a n n u a l
r e p o r t
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S p a c e
Space Telescope Science Institute
3700 San Martin Drive
Baltimore, Maryland 21218
Operated by the Association of Universities for Research in
Astronomy, Inc. in cooperation with the European Space Agency
for the National Aeronautics and Space Administration.
T e l e s c o p e
S c i e n c e
I n s t i t u t e
From the Director
1 From the Director | 3 Views | 11 News | 19 Reviews
20 Directors Office
25 Research Programs Office
23 Office of Public Outreach
27 Servicing Mission Office
30 Administration Division
29 Special Studies Office
33 Data Systems Division
39 Science & Engineering Systems Division
36 PRESTO
42 Science Support Division
By any measure,
the Hubble
science program
has changed
astronomy for
the better and
greatly increased
the public’s
appreciation
of astrophysical
research.
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c o n t e n t s
NEARLY AT THE MIDPOINT OF ITS LIFE,
the Hubble is considered NASA’s most
successful science mission ever as
measured by its impact on science and
the general public. In 1998 for example,
“Hubble was the most productive single
mission, providing 1.2% of discoveries
worldwide,” according to a NASA
compilation of research results. Deep
infrared imaging, the shock wave from
SN 1987a, and new findings on planetary
atmospheres are but a few of the results
cited in that study. Hubble has produced
more than twice as many discoveries as
the next most productive mission, Voyager.
The World Wide Web pages at the Institute
run by the Office of Public Outreach
record upwards of 4 million hits per week.
By any measure the Hubble science
program has changed astronomy for the
better and greatly increased the public’s
appreciation of astrophysical research.
1
V
iE
The Institute manages the science operations and public outreach activities for this most productive
Hubble mission. In being community-led and community-managed, the Institute’s arrangement is a
departure from the historical approach to NASA missions, and it is paying rich dividends, not only
to the science community but especially to NASA. One measure of the success of our management
arrangement is NASA’s early assignment of science oversight and operations to the Institute for the
Next Generation Space Telescope (NGST), scheduled for launch in 2008.
NGST will be an ambitious project with the same potential for scientific and public impact as
Hubble. Anticipation of NGST changed the course of the Institute in 1998. Because the Institute
plans to operate both Hubble and NGST with approximately the same number of staff that
currently run Hubble alone, we must increase our productivity over the next 10 years, a process
now underway.
The environment in which we strive
to optimize Hubble science, reduce
costs, and prepare for NGST is
delimited by the NASA budget.
Annual funding for the Hubble
project is about $225M, of which
the Institute receives $47M for tasks
related to Hubble, NGST and public
outreach. Additionally, we pass
$23M through to the community in
the form of grants and fellowships.
The remaining $155M is spent by
NASA on mission operations,
engineering, new instruments, and
servicing missions.
The Institute’s budget peaked in
1992 and has been slowly declining
since then. The projected budget for
the next ten years is approximately
level in constant dollars, but must
support both Hubble and NGST.
We estimate that the cost of running
NGST will be approximately onethird the current cost of Hubble,
implying a corresponding fractional
reduction in the cost of Hubble
operations by the launch of NGST
in 2008. The charts show the history
and future projections of Institute
budget and staffing.
Institute budget history and forecast
HST
OPO
NGST
Dollars in millions
The Institute
budget is
shown for tasks
related to
Hubble, NGST,
and public
outreach. The
budget figures
beyond fiscal
year 1999 are
estimates by
NASA.
Institute staffing history and forecast
HST
OPO
NGST
Full Time Equivalents
The Institute
staffing is
shown for
those charging
directly to
Hubble, NGST,
and public
outreach.
W
S
1 9 9 8 Wat c h W o r d s
Low-cost ops
Multiply Hubble science
“Low-cost ops” is an initiative to reduce the operating
costs of Hubble by one-third over the next ten years. This
initiative will make it possible to take on operations of a
second mission, the NGST, without increasing the total
budget of the Institute.
We re-analyzed Hubble science operations, looking for work that we could
phase out, places where process improvement would lead to savings, and
options for spreading the cost of operations infrastructure across two missions,
to achieve economies of scale. This ground-up build showed that we should be
able to operate Hubble for one-third less than we currently do. The major
savings come from not servicing the telescope after 2004. Servicing missions
add work all across the Institute and currently contribute more than 20% of
its total budget, and a much larger fraction of the overall program budget.
Process improvement is an integral part of low-cost ops. Productivity increases
may take some time to show up as cost savings, but we expect to achieve an
additional 6% budget savings from these efforts when they culminate early in
the next decade.
The third component of low-cost ops is decreased effort where that can be
done without a substantial reduction in the science output. For example,
support for redundant instrument capabilities (e.g. modes in two separate
cameras that deliver roughly the same images) might be cut back without a
loss of science. As another example, we used to check every proposal for
technical and programmatic feasibility. But since fewer than 20% of these
proposals will be approved, we could save effort by restricting the feasibility
checks to proposals conditionally recommended for approval by the Telescope
Allocation Committee. There is a sufficient pool of such savings options that
we are confident of reaching our overall goal of one-third total savings, even
with some reserves.
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Prepare for NGST
Low-cost ops
v i e w s
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5
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The Data Archive (Library)
achieved with
better command
software and
scheduling
innovations.
At the originally expected 33% efficiency rate,
an hour of observing on Hubble would be
worth about $165,000, or about $45 per
second, assuming the $4 billion total cost to
date of Hubble were spread over the 9 years of
life. Tripling the observing efficiency could
then be viewed as providing the science community with a bonus of research
opportunities of nearly 5800 hours worth $330,000 per hour, or about a
billion dollars, each year. The Institute’s cost of achieving this bonus was tiny by
comparison, which demonstrates the cost-effectiveness of process improvement.
HST Data Archive
Uncompressed
With Compression
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Percentage
When the Hubble was launched in 1990, the flight engineers estimated the
best observing efficiency that was achievable was about 33% time-on-target
with the instruments collecting useful data. The rest of the time, it was
thought, would be required for pointing the telescope, instrument setup,
calibration of the telescope’s systems, and avoiding regions of high radiation
or Earth obscuration of targets. Nevertheless, in 1998 the average observing
efficiency was 55% for a single instrument. And the overall efficiency for
collecting data exceeded 100% when we include parallel observing, which
means taking data with more than one instrument at the same time. These efficiency gains
came from improvements in the command
Annual Scheduling
Mission ”Lifetime to Date”
software and scheduling innovations, which
allowed calibrations and instrument setups to
take place at times when the telescope was
prevented from observing science targets.
Improvements
Our Project to REinvent Space Telescope
in Hubble
Operations (PRESTO) brought about these
observational
efficiency
process improvements.
By the end of 1998, the average retrieval rate was two to three times the rate
of new data entry. To the best of our knowledge, Hubble is the first astronomy
mission to have used a data library so actively while new observations were
still being gathered. This high usage attests to the wisdom of investing in a
well-planned archive, including easy access by non-experts and well-maintained calibrations to make every observation lastingly useful. Other observatories,
both space- and ground-based, are following the lead of the Institute in
recording and maintaining all their science data for future use; in fact, some
are using the Institute’s archive for this purpose.
v i e w s
Astronomy in the 21st century is emerging as a gestalt
consisting of more than just telescopes and astronomers, and
indeed is taking on cultural proportions. Hubble “multipliers”
are making no small contribution to this development. We
mean by this word such innovations as radically increased
observing efficiency, explosive growth of archival research,
and burgeoning programs of education and public outreach.
These innovations multiply and magnify the worth of
telescope time. We take pride that other missions, such as
the Advanced X-ray Astronomical Facility (Chandra) and the
Space Infrared Telescope Facility, are copying or emulating
the scheduling, archiving, and public outreach methods
pioneered at the Institute.
Observing Efficiency
Observing efficiency history
Historically, most science data from telescopes have been used just once:
analyzed, hopefully published, and not used again, except in the few cases
where a future observation of that region of the sky needed a past reference.
Even then, finding the needed data in usable format has been difficult because
of the rarity of cataloguing, preserving, and providing open, beneficial access
to original data. By contrast, all Hubble observations are stored in our data
archive-more aptly called a “data library”. This practice means that all Hubble
science observations, calibrations, and engineering data become available for
later reuse.
multiply hubble science
Total Data Volume (Terabytes)
7
Historical trends
in the data
volume of the
Hubble archive.
Comp.
SM-2
HST Data Archive
Ingest
Retrievals
Avg. Data Rates (GBytes/Day)
The rates at
which Hubble
data are added
to the archive
and are retrieved
for use by
scientists.
Public outreach
The outreach efforts of the Institute have had an enormous, positive impact
on the public’s perception of astronomy. Images of the heavens with Hubble’s
depth, color, and clarity capture the imagination and engage people from every
walk of life in the excitement of basic research. It is precisely such a diverse
audience we want to understand our mission. With lifetime run-out costs
exceeding $6 billion, Hubble is expensive to the taxpayer, and relies on public
understanding to justify continued support. Outreach is noble work, then, for
it returns value for value, conveying the wonder of the cosmos to an appreciative
audience. It will be increasingly important to do this work well for our future
science missions.
Such judgement calls are difficult to make. They highlight the importance of
having professional scientists involved in outreach at all stages of the process.
NASA has a good policy with Hubble press releases of always involving
scientists from the community, including outside experts not connected to
the observations in question. We have built trust among the best journalists,
who know that Hubble results are normally newsworthy, and we are gratified
by the public response we have helped achieve through the media. We will
continue to do this job well, and we expect to remain leaders in presenting
interesting science results to a wide audience.
The NGST project advanced dramatically in 1998, especially
with respect to the involvement of the Institute, which was
designated the NGST Science and Operations Center in
June. The Institute is now both leading the formulation of
NGST science objectives and developing concepts and cost
estimates for operating it. These dual roles signal a new
partnership with NASA, through which we are shaping the
NGST mission as a whole.
NGST is the first NASA project for which operational and spacecraft costs are
combined in reviewing performance requirements and telescope and instrument
designs. Issues about operability and cost versus scientific benefit—which were not
well joined for Hubble, and resulted in increased costs—are important matters for
NGST and the Institute. We recognize that the lessons learned from Hubble can
help ensure the programmatic success of NGST. The Institute takes seriously its
responsibility to manage the lifetime operations costs of the project in conjunction
with the cost of the flight hardware.
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At the end of 1998, our typical outgoing World
Wide Web traffic was about 35 gigabytes per day
or 1 terabyte per month! Public outreach content
typically accounts for 90-95% of traffic, with
those pages receiving typically 20 million hits per
month from hundreds of thousands of different
sites worldwide.
Sometimes outreach efforts can cause
controversy within the scientific
community. In response to a request
from NASA early in 1998, our Office
of Public Outreach supported a
news release in which a small object
appearing close to a young star was
interpreted as a runaway planet. The
possibility that this might be the first
image of an extra-solar system planet
created considerable stir within the
news community, but was greeted with skepticism by many scientists within
the sub-field of astronomy that deals with young stars and planets. The release
presented the result as an example of “discovery in progress”, but many people
thought that it would have been prudent to wait for confirmation before going
to the media.
Prepare for NGsT
v i e w s
In 1998 the Office of Public
Outreach had an excellent year for
publicizing Hubble science news. The
new instruments installed during the
servicing mission in 1997—the Space
Telescope Imaging Spectrometer
(STIS) and the Near Infrared Camera
and Multi-Object Spectrometer
(NICMOS)—provided new capabilities and many new discoveries.
The impact of these discoveries on
the public mind has been due in no
small part to the efforts of our
outreach staff.
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The ‘crown jewels’ of NGST are its science objectives: to understand the origin and
evolution of galaxies, and to study the physical structure and chemical composition
of the universe. Instrumentation strategies and observational scenarios flow from
those objectives. Further translations from scientific into engineering terms lead to
performance requirements and ultimately to the technical specifications and costs
of the NGST system itself.
Understanding the origin and evolution of galaxies involves observing galaxies and
stars in the early universe—objects at redshifts between 1 and 20. At these redshifts, the
familiar starlight and emission lines we study in local objects at visible wavelengths—
0.4 to 0.7 microns—will appear at much longer wavelengths, between 1 and 10 microns.
NGST will be optimized for that wavelength range.
To detect the earliest phases of star and galaxy formation requires long exposures and
superb sensitivity at near infrared wavelengths—ten times more sensitive than the
Hubble Deep Field programs. Resolving the first substructures in galaxies with redshifts
between 0.5 and 5 requires resolution of 0.06 arcseconds at 2 microns, which is
Hubble-like but at four times longer wavelength. Measuring physical properties of
individual galaxies calls for spectroscopy of emission and absorption-lines with broad
spectral coverage and low-to-moderate spectral resolution. Analyzing large numbers of
high-redshift galaxies to determine their properties, clustering, and rates of interaction
calls for imaging and spectroscopic surveys. These surveys must cover fields of
4 minutes of arc square or greater—large enough to include all likely progenitor
substructures within galactic regions comparable in size to the Local Group, as well as
the central regions of distant clusters of galaxies.
Astronomers would also like to detect and diagnose dust-enshrouded regions of vigorous
star formation or giant black holes in the nuclei of galaxies at redshifts between 1 and 2.
This would involve resolving the mid-infrared (5 to 28 microns) backgrounds, possible
if the NGST can be built with an extended wavelength range up to 25-30 microns.
9
NGST Discovery Space
While NGST must provide specific observing capabilities to reach its stated goals, it is widely
recognized that the greater the capabilities, the larger the potential for new discovery. The preliminary
designs indicate that NGST can readily cover the extended spectral range of 0.6 microns to more than
10 microns with slight increase in cost and dramatic decrease in risk to the overall mission. The ability
to reach further into the mid-infrared would give NGST almost unequaled potential to study star and
planet formation. For example, NGST will have a 100-1000 speed advantage
compared to SIRTF in the 10-30 micron range, depending on the design
temperatures of the NGST optics and sunshade.
Time to make an observation
NASA chartered the Ad-hoc Science Working Group to provide initial science
guidance to the NGST Program. It is co-chaired by John Mather, the Goddard
Space Flight Center Project Scientist for NGST, and Peter Stockman, the
Institute NGST Project Scientist. It includes a cross-section of the astronomical
community, including the principal investigators of the NASA-funded instrument feasibility studies. This working group has constructed a ‘design reference
mission’ to be an example of the science which NGST enables and to be a tool
for evaluating observatory designs. The current version of the Reference
Mission is accessible on the World Wide Web. (http://www.ngst.stsci.edu)
N
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W
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In 1998 NASA funded technology-development programs in a variety of areas
relevant to NGST, including deployable, ultra-lightweight, active, cryogenic
optics; wavefront sensing and control; large-format, high-sensitivity infrared
detectors; and lightweight, deployable sunshields. Though not completed,
these technology studies are already demonstrating that NGST is feasible with
known methods.
The time required for other observatories to
achieve a detection depth and areal coverage
similar to an NGST one-hour wide-field image.
A Design for NGST
NGST is an international project. The European Space Agency (ESA) will
contribute $200M (1996 dollars) toward instrument and spacecraft systems,
making its role in NGST comparable to its participation in Hubble. The
Canadian Space Agency intends to contribute $50 million. Both Europe and
Canada have set up NGST science teams, which are interacting with the
NASA team.
The NGST project is currently entering Phase A. NASA is soliciting two
prime contractor teams to perform parallel design studies, and one will be
selected to go on to build NGST. Eleven instrument-related studies are
underway in the US, Europe, and Canada. Meanwhile, AURA is entering
into a cooperative agreement with NASA under which the Institute will
guide the science planning and implement the operations of NGST.
The AURA-sponsored HST & Beyond Committee foresaw the enormous
potential of a scientific successor to Hubble optimized for the near infrared.
Their report, subtitled Exploration and the Search for Origins, called it, “. . . an
essential tool in an ambitious program of study in many areas of astronomy;
. . . especially powerful in studying the origin and evolution of galaxies. By
making detailed studies of these distant galaxies, whose light is shifted into the
infrared portion of the spectrum, we will be able to look back in time to study
the process of galaxy formation as it happened.”
This design uses an 8-m deployable segmented
mirror and science instrument module behind
a large sunshade. The sunshade allows the
entire assembly to cool radiatively to approximately 30 K. The telescope is placed in an
orbit at the second Lagrangian point of the
Earth-Sun system, which greatly reduces
thermal and dynamic disturbances to the
lightweight structure.
NGST is a focal point for two NASA priorities: addressing the “origins”
questions and building affordable yet technically advanced space observatories.
With Hubble, the Institute has demonstrated the scientific, technical, and
programmatic benefits of planning and operating such facilities by and on
behalf of the community. Thus, the Institute’s role in NGST is a great
challenge and an unrivaled opportunity for NASA, AURA, the Institute staff,
and the science enterprise as a whole.
discovered that the gas inside this galaxy is rotating
rapidly. A direct calculation of the mass of the black
hole at the center of NGC 7052 turns out to be 300
million times that of the sun. Accumulating evidence
now suggests that all galaxies may have black holes in
their centers, and that the normal galaxies of today
once made up the luminous quasar population of the
early universe. A short summary of research on black
holes is provided in the Science Appendix.
Second Hubble Deep Field “Down Under”
The Hubble Deep Field-North (HDF-N), a 10-day observation of the very distant universe in 1995, excited both
the scientific community and the general public. This unprecedented study fueled new research of distant
galaxies and spawned extensive follow-up observations across the electromagnetic spectrum, both from
major ground-based observatories and other satellites. This unparalleled observation also provided a springboard for the development of educational modules tied to middle school mathematics standards. The Space
Telescope Science Institute carried out a second deep field campaign, this time in the southern hemisphere,
in the fall of 1998.
T
Hubble’s suite of new
instruments—the
STIS, WFPC2 and
the NICMOS—
enriched the HDF-S
observation by
providing simultaneous,
parallel observations
of separate, neighboring fields.
Hubble web
simulcast takes
listeners on a “tour
of the cosmos”
Black Holes
Uncovered
y allowing scientists to peer into the highly
energetic centers of galaxies, Hubble continues
to make ground-breaking contributions in
the study of black holes. For several decades scientists
have known from observations across the electromagnetic spectrum that some galaxies have extremely
active regions in their cores. They have long
believed that this activity is due to the accretion of
matter onto massive black holes. One of the most
enigmatic active galaxies is Centaurus A, which
also contains a strong radio source. The galaxy has
a striking band of dust, gas, and young stars that
crosses the optical image, and is believed to be a
remnant of a merger between a large elliptical
galaxy and a small spiral galaxy.
The strong dust absorption had previously
prevented Hubble from obtaining an unobscured
view of the very central region; however, new observations with NICMOS have unveiled the galaxy’s
center. The observation revealed the existence of a
small nuclear disk of hydrogen gas, but surprisingly
this small disk is not aligned with any of the radio
features from the black hole. The merger is likely
to have contributed to the peculiar twisting in the
interior parts of Centaurus A.
In related studies, Hubble has provided detailed
diagnostic information for several other galaxies,
including NGC 7052. Using STIS, observers
B
n the summer of 1998, the Office of Public
Outreach (OPO) for the first time used multimedia
technology to stream video of Hubble’s latest
science images along with real-time audio from the
NPR radio show, The Marc Steiner Show. If listeners
missed the live broadcast, OPO continues to offer the
recorded program, including spectacular space images
and animation, on the Internet. The ongoing series
now is called Tour of the Cosmos. During the Tour
of the Cosmos program, Steiner discusses a variety of
science topics—cosmology, the formation of other
planetary systems around new stars, and exploration
of the solar system—with guest scientists, Hubble
scientists, and the director of the Davis Planetarium in
Baltimore, Maryland. Hubble webcasting has received
such wide approval from the public and major news
and information outlets, including CNN Science
and Technology, Yahoo! and others, that it now is a
regular feature of NASA Space Science Update press
conferences. See (http://hubble.stsci.edu)
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While it is too soon to assess the lasting impact
of the HDF-S observations, early analysis has
revealed the presence of high-redshift (z > 1) elliptical
galaxies, which do not appear in the HDF-N. The
observation also has revealed a higher density of
star-forming galaxies with “photometric” redshifts
z > 4.5. Both results suggest that the overall rate of
star formation within the first few billion years after
the Big Bang was considerably higher than it is
today. Perhaps this vigorous rate is even comparable
to the “baby boom” of galaxies bursting into view a
few billion years later. More details of the HDF-S
are given in the Science Appendix and on the World
Wide Web. (http://www.stsci.edu/ftp/science/hdf/hdf.html)
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he Institute’s scientists rationalized that the first
deep field three years earlier had produced a
wealth of information, and that a second would
provide a further dimension to these results. The
thinking proved correct. Hubble’s suite of new instruments—the Space Telescope Imaging Spectrograph
(STIS), Wide Field Planetary Camera 2 (WFPC2)
and the Near Infrared Camera and Multi-object
Spectrometer (NICMOS)—enriched the Hubble
Deep Field-South (HDF-S) observation by providing
simultaneous, parallel observations of separate,
neighboring fields. The STIS observation, for
example, resulted in a deep optical “white light” image
of a field surrounding a previously known quasar. It
now holds the record
for the deepest optical
image ever taken,
recording galaxies with
flux levels equivalent
to one photon per
fortnight striking the
human eye. The
other half of STIS’s
observing time was
used to measure
absorption lines from
intergalactic hydrogen
along the line of
sight to the QSO,
providing vital information on physical
conditions in the
intergalactic medium
at redshifts z ~ 1-2.
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HUBBLE HERITAGE
UNVEILS COLORFUL
PHOTO GALLERY
A
OMC-1
he Near-Infrared Camera and Multi-Object
Spectrometer (NICMOS) produced highquality science over the course of its short life,
including studies of distant galaxies such as the one
depicted in the figure. It unveiled star-formation
regions and the planetary disks that are forming
around stars.
Unfortunately, NICMOS’s life was cut short by
a thermal short in its dewar. Through engineering
and calibration, a quick ancillary “Call for Proposals,”
and a concentrated effort to optimize telescope
scheduling, the Insitute accelerated the use of
NICMOS. The Space Telescope Science Institute set
an ambitious goal of spending half of the available
orbits on near-infrared observing so that the total
observing program could be completed by a conservatively set date of November 1998. The program was
completed, with margin to monitor the behavior of
NICMOS as it warmed up. NICMOS exhausted all
of the available cryogen by January 1999, and observers
now look forward to the installation of the NICMOS
cryo-cooler during a future servicing mission that
will restore HST’s productivity in the infrared.
NGC 7742
T
H
NGC 253
New Roles for the
Institute with Wfc-3
he Space Telescope Science Institute will play a
strong role in the design and development of
WFC-3 through a partnership with the Goddard
Space Flight Center, the Jet Propulsion Laboratory, and
Ball Aerospace. In particular, the Institute is closely
teamed with our GSFC counterparts: we provide both
managerial and technical staff to help build and operate
the camera. The deputy Instrument Scientist and the
deputy Instrument Manager are both Institute staff and
other Institute will fill key technical and scientific roles.
The Institute has played a special role in adding a
near-infrared channel for WFC-3. A group of scientists
tasked with recommending strategies for achieving the
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Ring Nebula M57
Institute Picked for
NGST Science and
Operations Center
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A RACE TO THE
FINISH: COMPLETING
HUBBLE’S NEARINFRARED SCIENCE
PROGRAM
onored by his peers for bold and innovative
research, former Institute Director Robert
Williams received the prestigious Beatrice M.
Tinsley Memorial Prize at the January 1999 meeting
of the American Astronomical Society. Williams was
honored for his foresight and vision in using his
Institute discretionary oberving time to conduct the
Hubble Deep Field observation in 1995. At the time,
the Hubble Deep Field-North observation was the
deepest look ever at the universe, and galvanized the
research community and public alike. It has provided
profound new insights into the origin, evolution,
and structure of galaxies in the universe.
The prize was established in January 1985 in
honor of Beatrice Tinsley’s unique achievements in
astronomy. The Tinsley Prize recognizes an outstanding
research contribution by an individual, or individuals,
to astronomy or astrophysics. Consistent with
Tinsley’s own work, the award focuses on contributions
that are of an exceptionally creative or innovative
character and that have played a seminal role in
furthering our understanding of the universe.
optimum science return from Hubble in the next
decade (The “Second Decade Committee”) met in July
1998 and after considerable discussion and study,
recommended the addition of an infrared channel on
WFC-3. They concluded that such a capability would
enable Hubble uniquely to address a broad range of
important astrophysical questions and issues, especially
on studies of star-formation in our own Milky Way as
well as in galaxies at very high redshifts.
The support for this new IR channel was so strong
that the Institute’s science body voted unanimously to
provide funding from its own research pool to allow
technical feasibility studies to proceed without delay.
The strong message from the science community
was heard by NASA, and approval to proceed with
technical studies followed.
N e w s
vibrant celestial photo album of some of NASA
Hubble Space Telescope’s most stunning views
of the universe was unveiled on the Internet
in the fall of 1998. Called the Hubble Heritage
Program, this Technicolor gallery is being assembled
by a team of astronomers at Space Telescope Science
Institute. The Hubble Heritage program is intended
to provide the public with some of the very best
celestial views the telescope has to offer. Each month
one additional picture, distilled from Hubble exposures, is exhibited; however, the Institute frequently
offers supplemental illustrations, stories, explorations,
and educational information throughout the month.
See (http://heritage.stsci.edu) and Science Appendix
ROBERT WILLIAMS
AWARDED FOR
EXPANDING THE
UNIVERSE WITH THE
HUBBLE DEEP FIELD
he Space Telescope Science Institute was
designated as the NGST Science and Operations
Center. NASA based its decision on the
Institute’s very successful and well-regarded operation
of Hubble, which included service to the international
scientific community. Choice of the Institute for the
NGST center means that the experience derived from
nearly a decade of Hubble operations can be incorporated
into building NGST and planning for its operations
at a very early stage. This should permit greater
participation in NGST by the scientific community,
including such areas as major collaborative programs
involving the two observatories and techniques for
efficient scheduling of complex scientific programs.
Location of the NGST Science and Operations Center
at the Institute also will realize significant financial
savings, as the NGST project will not have to support
new infrastructure or staff.
The option for the Institute to take on responsibility
for NGST science operations was evaluated and
unanimously supported by the Origins Subcommittee
of the Space Science Advisory Committee, which
specifically cited the benefits to the scientific community.
Democratic Maryland Senator Barbara Mikulski and
NASA Administrator Daniel Goldin announced the
decision to Institute staff on June 8, 1998.
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15
Research on
black holes
Centaurus A has contributed to its peculiar twisted
and mass measurements for galaxy centers are now
morphology. Galaxy activity has often been linked
available, many from Hubble. This has allowed the
to interactions, and the detailed view that Hubble
first tentative studies of the black hole demography
is giving us of this particularly nearby galaxy sugin galaxies. The results indicate that the mass of the
gests that the feeding of black holes can be a very
black hole in a galaxy is proportional to the mass of
complex process.
the galaxy itself, typically making up 0.5 percent of
In conjunction with imaging studies such as
the total galaxy mass. This relation holds both for
those of Centaurus A, Hubble has continued to
elliptical galaxies and for spiral galaxies, provided
perform spectroscopic studies of other galaxies. A
that for the latter only the mass of the spheroidal
disk of dust and gas 30 times larger than the small
bulge component is used.
nuclear disk in Centaurus A was studied in the active
Active galaxies, and in particular quasars, were
galaxy NGC 7052 (Figure 2). Spectra of the gas
much more numerous in the past than they are now.
show the disk to be rotating
Studies of the number and
rapidly, as was found for
luminosity of quasars in
several other galaxies studthe early universe provide a
ied by Hubble in previous
direct constraint on the
years. The rotation velocity
total mass that must have
of the disk allows a direct
accumulated into black holes
calculation of the mass of
through quasar activity. The
the black hole, which for
results from such studies
the case of NGC 7052
are consistent with the
turns out to be 300 million
notion that all galaxies in
times that of the sun.
the present universe have
The activity in a galaxy
black holes with masses
may cease when the black
similar to those inferred by
hole in the center runs out
Hubble for nearby active
of fuel, or when this fuel
galaxies. So it now appears
stops being efficiently transclear what happened to the
Figure 1. Close-up view with WFPC2 of the nearly edge-on dust disk
formed into radiation. So
population of luminous
girdling Centaurus A, the nearest active galaxy to Earth. NICMOS
it is believed that many
quasars that lit up the
was used to peer through the dust to discover a tilted, 130 light-year
diameter disk of hot gas around the suspected black hole in the
normal, quiescent galaxies
universe when it was
galaxy
center.
(From
Schreier
et
al.,
1998,
ApJ,
499,
L143.)
may have had an active
young: these quasars have
phase in the past. If so, they
evolved into the normal
would also have massive
galaxies that we see around
black holes lurking in their
us today!
centers. For some years now,
Without any doubt, the
Hubble has been detecting
remarkable capabilities of
and weighing black holes in
Hubble will continue to
normal galaxies through
contribute in the coming
analysis of the motions of
years to our understanding
stars near galaxy centers.
of black holes in galaxies
The year 1998 brought
and the role that they play
spectroscopic confirmation
in the overall evolution
of the presence of a black
of galaxies.
hole in our nearest neighbor,
the spiral galaxy M31 in
Figure 2. A 3,700 light-year-diameter dust disk in the center of the
Andromeda. Since ground-based observations of the
elliptical galaxy NGC 7052 imaged by WFPC2. The upper left insert
center of our own Milky Way Galaxy have revealed
shows a larger-scale ground-based view. Spectroscopic observations
a massive black hole as well, black holes do indeed
show that the disk is spinning rapidly around a 300-million solar-mass
black hole. (From van der Marel and van den Bosch, 1998, AJ, 116, 2220.)
appear to be common also in normal galaxies.
A total of several tens of black-hole detections
By Roeland van der Marel
ecades of observations over a large range of
wavelengths, from radio waves to gamma
rays, have revealed that a few percent of all
galaxies display highly energetic activity in their
centers. These galaxies are generally known as “active
galaxies”, or in extreme cases, as “quasars”. The
observed activity does not arise naturally in conventional collections of gas and stars, and since the
1960’s, astronomers have believed the observed
phenomena result from accretion of matter onto
massive black holes. Long before Hubble was
launched, it was expected to make breakthrough
discoveries about black holes, because Hubble allows
us to peer into the centers of galaxies in more detail
than ever before. Throughout 1998 Hubble has
continued to live up to these expectations.
One of the nearest—and at the same time one
of the most enigmatic—active galaxies is Centaurus
A. It was one of the first galaxies to be identified as
a strong radio source. An optical image, Figure 1,
shows that the galaxy is bisected by a prominent
band of dust, gas, and young stars. This feature has
led astronomers to believe that Centaurus A is the
remnant of a merger between a large elliptical galaxy
and a small spiral galaxy.
Strong dust absorption obscured Hubble’s view
of the central region of Centaurus A until the
installation of the Near Infrared Camera and MultiObject Spectrometer (NICMOS) in 1997. Because
near-infrared light is absorbed up to 10 times less
than visible light, NICMOS has been able to image
the region close to the suspected black hole for the
first time.
NICMOS images of Centaurus A have revealed
the existence of a nuclear disk of hydrogen gas only
130 light-years across, which is the smallest nuclear
disk in an active galaxy yet imaged with Hubble.
Interestingly, the disk is not perpendicular to axis
of the jet of radio emission that emanates from the
black hole. This is surprising, since theoretical models
predict that the radio axis should be perpendicular
to the accretion disk that ultimately feeds the black
hole. Although this finding remains to be explained
in detail, it is likely that the recent merger history of
D
AURA APPOINTS A
NEW DIRECTOR FOR
THE SPACE TELESCOPE
SCIENCE INSTITUTE
URA appointed Dr. Steven V. W. Beckwith as
the Director of the Space Telescope Science
Institute in 1998 after former Director Robert
E. Williams decided to step down to focus primarily
on his research. Under Williams’ guidance as Director
for five years, the Institute went to great lengths to
service the Hubble user community and maximize
the science output from Hubble. Williams’ most
notable legacy is the Hubble Deep Field observation,
which he immediately shared with the astronomical
community. It was a challenge to AURA to find a
new director who could lead the Institute into the
millennium and a bright future with the Next
Generation Space Telescope (NGST).
Beckwith brings experience, energy, and vision
for the future of the Hubble project. He enthusiastically embraces the challenge and reward of carrying
Hubble science operations forward into the next
century. Beckwith’s research in infrared astronomy
makes him ideally suited for overseeing the Institute’s
work toward operating NGST. In accepting the
position, Beckwith said, “The Institute is one of the
most exciting new institutes in astronomy. The
Hubble Space Telescope is the first of what I hope will
be many important space projects for the Institute.”
Formerly director of the Max-Planck Institute for
Astronomy in Heidelberg, Germany, Beckwith
combines more than 20 years of scientific research
with significant international management experience. He is an excellent choice for fulfilling AURA’s
role in supporting NASA’s space science program.
A
|
SCIENCE APPENDIX
N e w s
SCIENCE APPENDIX
17
SCIENCE APPENDIX
The Hubble deep field south
By Henry Ferguson
n December 1995, the Hubble Space Telescope
pointed at an undistinguished high-galactic
latitude patch of sky in the northern hemisphere,
and observed for 10 straight days. The result was
the deepest optical image of the sky yet obtained: the
Hubble Deep Field North, or HDF-N. The images
allow detection of sources as faint as visual magnitude
V = 30 in four bandpasses spanning the near-UV to
the near-IR. The data were released to the community
within one month of the observations and have been
used in a wide variety of projects and publications,
ranging from studies of the star-formation rate as a
function of redshift to studies of faint M dwarfs in
the Galactic halo.
A second Hubble deep-field campaign, in the
southern sky, was carried out between late September
and October of 1998. The raw, pipeline calibrated
and reprocessed data were released to the community
on November 23, 1998. (The highest Internet traffic
ever experienced by the Institute occurred after the
release of the HDF-S data—over 200 Gbytes transferred in the first 24 hours.)
The rationale for undertaking the second
deep-field campaign followed from the wealth of
information that has come out of HDF-N, and from
the desire to provide a similar point
of focus for studies of the distant
universe from southern-hemisphere
facilities. The wide public access to
the HDF-N data stimulated extensive
follow-up observations across the
electromagnetic spectrum, both from
major ground-based observatories
and from other satellites. A similar
level of effort is now underway for
HDF-S, with major programs being
undertaken at the European Southern
Observatory and the AngloAustralian Telescope. The Institute is acting as a
clearinghouse for supporting and follow-up observations of the HDF-S.
As was the case for HDF-N, the southern field is
located in the zone of continuous viewing for Hubble,
near the pole of its orbit, which maximizes the observing
efficiency. A moderate redshift quasar (z ~ 2.24) was
placed in the field of the Space Telescope Imaging
Spectrometer (STIS) so that correlations could be
I
determined between quasar absorption redshifts and
those of galaxies in the field.
Simultaneous, parallel observations of separate,
neighboring fields were made with three Hubble
instruments—STIS, the Wide Field and Planetary
Camera 2 (WFPC2), and the Near Infrared Camera
and Multi-Object Spectrometer (NICMOS). The
STIS and NICMOS observations are significant
enhancements over what was possible during the
HDF-N campaign. Roughly half of the observing
time with STIS was spent obtaining a deep optical
“white light” image of the field surrounding the
quasar. This image now holds the record for the deepest
optical image ever taken, recording galaxies with flux
levels equivalent to one photon per fortnight striking
the human eye. The other half of the observing time
with STIS was used to measure absorption lines from
intergalactic hydrogen along the line of sight to the
QSO, providing vital information on physical conditions in the intergalactic medium at redshifts z ~ 1-2.
The actual observations of the HDF-S were
similar in spirit to the original HDF. As was the case
for HDF-N, approximately 150 consecutive orbits
were devoted to a single telescope pointing.
Additional flanking-field observations were made,
surrounding the deep STIS, WFPC2
and NICMOS fields.
The HDF-S data were reduced
in less than six weeks by members of
the Institute staff, with help from
visiting scientists from the European
Coordinating Facility and the STIS
Instrument Development Team.
While it is too soon to assess
the lasting impact of the HDF-S
observations, early analysis has
revealed the presence of elliptical
galaxies at high redshifts (z > 1),
which appeared to be absent from the HDF-N. Also,
HDF-S has revealed a higher density of star-forming
galaxies with “photometric” redshifts z > 4.5. Both
of these results suggest that the overall rate of star
formation in the universe within the first few billion
years after the big bang was considerably higher than
it is today, and perhaps even comparable to the “baby
boom” of galaxies bursting into view a few billion
years later, at redshifts z ~ 1.
R
E
vieWS
The director’s Office
Program Management
Advisory Committees
Through Hubble and NGST, the
Institute has a bright future.
We create the strategic vision to guide
the Institute into the future. We strive
to ensure that the Hubble science
program remains vigorous throughout
the life of the mission and that the
Institute continues beyond the Hubble
with new initiatives.
In 1998 we led four activities that
exemplify our commitment to
Hubble’s excellence and the Institute’s
future: the Hubble Deep Field
South, the “low-cost ops” effort, the
enhancement of WFC-3 with infrared
capabilities, and definition of the
Institute’s role in NGST.
The Hubble Deep Field South is
the southern hemisphere analogue of
the highly successful Hubble Deep
Field, which was a director’s initiative
using discretionary time to obtain
the deepest view of the universe ever.
Carried out in October 1998 under
the supervision of past-director
Robert Williams, the Hubble Deep
Field South more than doubled the
data on the early universe at visible
wavelengths, and used the new
instruments NICMOS and STIS to
add important views in the infrared
and the ultraviolet.
Low-cost ops is a ground-up
build of the services we currently
provide to NASA and the user community extrapolated into the future.
Some of the tasks we do now in
support of servicing missions can be
eliminated after the final servicing
mission in 2004. We continuously
improve our processes to become
more efficient. We identify services
that might be reduced without a loss
of science productivity. Altogether,
our low-cost ops plan will save
approximately 30% of the current
operating budget.
The Director’s Office led the
effort to approve the proposed nearinfrared capability initiative for
WFC-3. We were successful in obtaining endorsements from all the relevant
advisory committees. Working with
NASA, we have achieved conditional
approval to add this new capability
to the WFC-3 instrument definition,
which should help ensure an exciting
science program for Hubble until the
completion of its mission.
NGST represents the future for
Hubble’s kind of science, and the
Institute has embarked decisively to
ensure NGST’s success in technical,
programmatic, as well as scientific
terms. We appointed Ethan Schreier,
an associate director, to manage the
Institute’s NGST team. By the end
of 1998, this team identified tasks and
produced a staffing plan for NGST
operations from now to launch in
2008 and into steady operations after
2010. We are in an excellent position
to advise NASA and the community
on operational cost tradeoffs of various
telescope and instrument concepts.
We are poised to move from a singlemission to a multi-mission organization. Meanwhile, we continue to
examine ways to broaden further our
base, including with new proposals
and the use of commercial products
in support of space science.
Program Management
We optimize the allocation of resources
to meet our goals and responsibilities.
In 1998 the overall performance of
the Institute was excellent. NASA
rated it at 99%—subtracting 1%
because we under-spent our budget
by about a million dollars. NASA
requires more predictability for their
planning, and we have taken steps to
improve our projected expenditures.
In large part, the 1998 underspending was due to unfilled positions,
which means that addressing the
problem will also improve workloads.
We have authorized some over-hiring
of science and technical staff to
|
Leadership
The year 1998 was a turning point for the Institute.
Leadership passed to a new director. NASA designated us
to conduct the science program and mission operations for
the Next Generation Space Telescope (NGST). Hubble
continued to produce new results at the forefront of science
while engaging the public in astronomical research. The
community of Hubble has expanded with new observers,
increasing numbers of archival researchers, and a growing
public audience.
This was the year of three directors: Robert Williams,
whose term ended July 31, Michael Hauser, acting director
for the month of August, and Steven Beckwith, selected by
AURA to be the new permanent director, whose five year
term began on September 1. Returning to the U.S. from
Heidelberg, Germany, where he directed the Max Planck
Institute for Astronomy, Dr. Beckwith got to know the
people and operations of the Institute, and conveyed his
vision of the future to the staff.
On June 8, Senator Mikulski and NASA Administrator
Goldin made the announcement that the Institute would
be the Science and Operations Center for NGST. We have
begun planning the evolution of our organizational structure
to operate Hubble and NGST simultaneously, with no
cost increase. The anticipated operations costs of NGST
are approximately one third of Hubble’s current costs.
Thus, we will reduce Hubble’s operational costs by a third
while maintaining its scientific productivity.
Leadership
r e v i e w s
We are responsible for overall management of the Institute—
establishing policy, organization, and strategy, obtaining
and managing resources—and for conducting the external
relations of the Institute, including reporting to oversight
committees and soliciting and receiving advice from advisory
groups. We ensure the Institute succeeds in its commitments
to NASA, the scientific community, and the public.
At the request of NASA, we
convened a committee to develop a
strategic plan for Hubble science in
the second half of its mission. The
Second Decade Study produced two
major recommendations in 1998,
which we are pursuing on behalf of
the science community. The first is to
extend into the infrared the sensitivity
of the wide-field camera (WFC-3) to
be installed on the last servicing
mission. This extension will exploit
the rich discovery space pioneered
by the first Hubble near-infrared
camera, NICMOS. The second is to
allocate approximately one fourth of
Hubble’s orbits to large programs.
Large programs on Hubble have had
a disproportionately positive impact
on science relative to the smaller ones
as measured on a per-orbit basis.
By every statistical measure, and
by every formal and informal channel
of feedback to the Institute from
its wide community, Hubble is an
outstanding success. The preeminent
place of Hubble in astronomical
research is evident in papers, collaborations, meeting topics, and headlines.
It is also reflected in young people
being drawn into science, and new
generations of astronomers finding
employment opportunities and
research directions created or influenced by Hubble. This is the living
legacy of Hubble, which will continue
long after the expected end of
mission in 2010.
21
Our advisory committees counsel us on
optimizing our services to the community.
We have three standing advisory
committees with terms of reference
outside the Institute, and two that
are creations of the director, one of
which is currently dormant. The
Space Telescope Institute Council
(STIC), our primary management
oversight committee, is selected by
and reports to the AURA board of
directors. The Institute Visiting
Committee (IVC), which evaluates
the productivity, working conditions,
and morale of the staff, is selected by
STIC and reports to NASA through
AURA. The Space Telescope Users
Committee (STUC) is selected by
and reports to both the Institute
director and the NASA project
scientist on matters related to the
utility of the telescope and the quality
of Institute services. The Telescope
Allocation Committee (TAC) is
The Interim IVC met in April
1998 to review the Institute’s progress
toward meeting its goals and objectives, assess its response to matters
arising since the previous IVC meeting,
and survey the perspectives and issues
of Institute staff. The committee’s
comments about the overall performance and responsiveness of the
Institute were very positive. They
called particular attention to the
effectiveness with which we carry out
the selection and implementation of
the Hubble science program, and
noted the innovation with which we
deal with programmatic changes. The
IVC also commented positively on
our outreach and education activities
as well as our preparations to support
NGST. The IVC noted with concern
the high workload for all the staff, a
situation we intend to relieve with
additional hiring and a reduction in
the tasks. They recommended a review
of the Administration Division,
previously suggested by the IVC was
again endorsed, and we completed
this review in November.
The TAC and its 16 panels met
in October and November 1998 to
select a total of 295 new General
Observer, Snapshot, and Archival
programs from a pool of 1053 proposals. The total number of primary
orbits requested was 14,005, from
which we assigned 3314 to selected
proposals. On its own initiative, the
TAC made a number of specific
recommendations regarding improvements to be made in future cycles. In
particular, it gave strong support to
the concept of allocating an increased
fraction of the observing time to
large (i.e., greater than 100 orbits)
programs. The Cycle 9 Call for
Proposals will encourage the submission of these large programs.
office of public outreach
We employ the scientific discoveries and
technological advances from Hubble to
make research and expertise accessible and
relevant to the public.
By developing exemplary programs, we bolster mathematics,
science, and technical education and contribute to an
improved public understanding of science and technology.
We investigate methods that sensibly integrate the communities of researchers, engineers, and technologists, both
locally and nationally, into public programs. We encourage
effective dissemination networks, with a result that scientists
and engineers are motivated to take an active role in
science communication.
We also diffuse knowledge about the Hubble mission
and Institute services to the astronomy community itself.
For example, we have arranged major displays about HST
results and Institute activities at meetings of the American
Astronomical Society. During 1998, we began a major effort
in coordination with NASA to inform the community
about NGST, which included planning public meetings,
publishing NGST documentation, and preparing requested
material for the National Research Council’s decadal survey.
In 1998 Hubble continued to captivate public interest
and inspire more people to take an active interest in science.
Hubble, as an icon of discovery, fascination, and erudition
is a springboard for leveraged, effective programs of
education and outreach.
|
Advisory Committees
appointed by the director to evaluate
observing proposals and recommend
an allocation of Hubble orbits to
selected programs. Finally, the
currently-inactive Space Telescope
Advisory Council (STAC) is available
to the director for advice on any
subject related to the Hubble
science program.
STIC met three times in 1998
(February, June and October). The
relationship between the Institute and
this committee is excellent. STIC has
been very supportive of a number of
initiatives, including our new role in
the design and development of the
WFC-3 and our advocacy of a nearinfrared channel for this instrument.
Also, STIC strongly endorsed the
selection of the Institute as the Science
and Operations Center for NGST,
and has been supportive of the resulting internal activities and managerial
changes. In 1998 two tenure cases
were brought forward to the STIC,
endorsed, and subsequently approved
by the AURA board of directors.
STIC played an important role in
the search for the new director.
STUC met twice in 1998 (May
and November). It made a number of
recommendations, the great majority
of which have been adopted by the
Institute. STUC members participated
in the analysis of the user survey sent
to all Hubble users. Also, STUC
strongly endorsed the inclusion of a
near-infrared capability in WFC-3.
r e v i e w s
compensate for natural turnover.
With new Hubble instruments and
NGST on the horizon, we also need
to increase expertise in infrared
astronomy, detectors, and instrument
development. We have begun addressing these needs through an aggressive
—and successful—hiring campaign
begun in 1998.
The Institute will be a more
complex organization as it takes on
operational responsibility for a new
mission while operating Hubble more
efficiently and with no compromise
of science. This increasing complexity
will necessitate improving our management tools and methods. In 1998
we commissioned new accounting
systems capable of operating in a
multi-contract environment. Also,
we initiated a survey of the Institute’s
management culture to identify
those areas where we need training
to improve or acquire skills.
23
K–12 Curriculum Support
Public Understanding of Science
The News Program
Origins Education Forum
K-12 Curriculum Support
We develop curriculum products based
on Hubble.
Public Understanding of Science
We reach a broad audience with
Hubble results via learning institutions
and the Internet.
The public’s natural curiosity about
space, astronomy and technology
allows us to bring the excitement of
scientific discovery and technological
accomplishment to a wide audience
through science museums, planetaria,
libraries and information networks.
We are able to reach a broad audience
through interactions with key members of the informal science education
community. Science museums
regularly feature Hubble images and
consult with us to tune their exhibits
and planetarium productions. We
continue to collaborate with the
Smithsonian Institution on the
In 1998 we began utilizing
multimedia technology to stream
video of the science images along
with real-time audio from an NPR
radio program, The Marc Steiner
Show. If listeners have missed the
live broadcast, our web site offers the
recorded program, with spectacular
space images and animation added.
In this way, space enthusiasts and
educators on the World Wide Web
can “tune in” to hear Marc discuss a
variety of science topics in depth
with Hubble scientists and other
experts and science educators.
The News Program
We prepare Hubble press releases.
Exciting scientific findings from
Hubble are disseminated through the
news media in televised press conferences, press kits, and electronic releases
of newsworthy materials. The press
conferences offer an opportunity for
the press to interact directly with
(http://www.stsci.edu/pubinfo/pr.html)
Origins Education Forum
We coordinate the education and public
outreach efforts of all of the NASA
missions that are collected within the
Origins Theme.
NASA Origins Theme includes such
missions as SIRTF, SOFIA, the
NGST, Keck, FUSE, Hubble, and
the Astrobiology Institute. The forum
serves as a central jump station for
public information about NASA
missions, their scientific results and
publicly available materials useful to a
wide audience, especially professional
educators. (http://origins.stsci.edu/)
NASA also offers funding incentives for scientists who collaborate
with educators through the Initiative to
Develop Education through Astronomy
and Space Science (IDEAS), which we
manage. (http://ideas.stsci.edu/)
In 1998 approximately 10% of
Hubble Guest Observers also responded
to an opportunity through the
Hubble Cycle 8 Call for Proposals
to obtain funds for conducting outreach programs tied to their research
programs. (http://origins.stsci.edu/cycle8/)
Research Programs Office
We support the research activities of Institute staff.
We sponsor and provide logistical support for scientific
meetings, run the library, support administratively the
postdoctoral fellows and graduate students, conduct the
Hubble Fellowship program, facilitate research visitors,
and manage the allocation of the director’s research fund.
The general objective of scientific meetings at the Institute is
to enhance staff research while making lasting contributions
to the progress of science. In 1998 the Research Programs
Office organized and hosted the annual May Symposium,
entitled “Unsolved Problems in Stellar Evolution”, which
was one of our most successful to date. The symposium
attracted 140 experts on stars from around the world for the
four-day meeting. As is customary, the proceedings were
published by Cambridge University Press. The Hubble
Fellow Symposium is another outstanding annual event.
Held this last year in October, it brought together 30
Hubble Fellows to present talks on their current research,
which constituted a broad tour of the frontiers of astronomy.
We also assisted Johns Hopkins and the Institute’s Galaxies
Journal Club in organizing a mini-workshop entitled “When
and How Do Bulges Form and Evolve?”
Our visitors program is a valuable resource for both the
Institute staff and the outside astronomical community. It
encourages and supports astronomers from around the world
to come to the Institute for intensive collaboration with our
research staff. In 1998 a total of 96 visiting researchers spent
time at the Institute ranging from a few days to a few weeks.
At any one time, we host an average of six visiting scientists.
Our Hubble Fellow Program is arguably the most
influential postdoctoral fellowship program in astronomy.
It provides three-year support for competitively-selected
recent PhDs in astronomy, physics, and related disciplines,
who pursue research broadly related to the Hubble mission
at participating host institutions throughout the United
|
(http://amazing-space.stsci.edu/)
(http://hubble.stsci.edu)
the investigating scientists. Nearly
once a week, a new image or result
is released often with valuable background materials.
In 1998 we supported the kickoff of the new Hubble Heritage
Project, producing stunning images
culled from the Hubble archive, with
a new release at the beginning of
each month.
1n 1998 the media coverage of
Hubble included approximately 800
science articles in major U.S. newspapers, nearly 925 broadcast media
reports, and several dozen articles in
major news magazines. A review
published in Science News for the
year 1998 reported that Hubble
contributes about 1.5% of the significant scientific advances across all
fields including medicine and technology, dominating the astronomy
field, in particular.
r e v i e w s
Our curriculum-support team
develops online and hardcopy
products incorporating Hubble data
and research into materials that are
directly relevant to K-12 curricula
and address specific national standards.
The heart of the team’s effort is a
5-week-long summer workshop,
which produces online laboratories
and interactive modules to trigger
students’ fascination with space.
The intended outcome is improved
math, science, and technical skills.
Authoring these materials is a collaborative effort between K-12 teachers,
graphic artists, writers, web developers
and Institute scientists and technologists. Materials are reviewed, tested,
and disseminated nationally. The
modules are also demonstrated at
workshops held at national professional meetings such as the National
Science Teachers Association,
National Council of Teachers of
Mathematics, Association of Science
and Technology Centers, and the
American Astronomical Society.
development of a traveling exhibition
featuring Hubble science and technology.
The rapid growth of Internet
use by the general populace has been
manifest in the staggering growth of
our World Wide Web site’s popularity.
As a leader in the NASA community,
and with an excellent talent mix of
personnel, we conduct experiments
using information technology. The
goal is to improve public understanding of and access to science results
and expertise through the internet.
We broadcast Space Science Updates,
which are NASA press releases, over
the Internet to reach millions of users.
In doing so, we provide a suite of
resources to individuals and educators
alike. Major news media web sites—
CNN, MSNBC and ABC, as well as
the Washington Post and New York
Times—constitute an increasingly
important dissemination channel for
us. They now carry significant
amounts of our web-based materials,
such as images, graphics, video clips
and audio interviews.
25
hubblefellow.html)
February cycle and 12 in September.
One of the new projects is a longterm program under the direction
of John MacKenty to develop a new
type of infrared multi-object spectrograph. Regarding publications, we
produced 107 preprints in 1998,
and paid $107,105 in journal page
charges, of which $66,105 was
recovered from grants. Finally, with
support from the entire scientific
staff, the director has allocated money
from his research fund to support a
near-infrared channel in the WideField Camera 3, to be installed on
Hubble in the final servicing mission,
currently planned for 2003.
We organize a committee to
recommend Institute astronomers for
various local and national awards. The
committee had a successful year in
1998, with the acceptance of its
nominees for the Beatrice M. Tinsley
Prize, Robert E. Williams, and the
George Van Biesbroeck Prize, the late
Barry M. Lasker. In addition, the
committee recommended to AURA
that the 1997 AURA Science Award
go to Harry Ferguson, who received
this honor at a special ceremony at
the Institute hosted by Dr. Oertel.
Looking forward to 1999, we see a
steady increase in our science researchsupport activities as we strengthen our
research staff and diversify the kinds
of astronomy we do at the Institute.
Our recent designation as the Science
and Operations Center for NGST
offers a vital long-term perspective in
this regard, broadening our intellectual
scope and making the Institute even
more attractive for young researchers.
We are committed to contributing to
the scientific leadership of the Institute
and to strengthening the Institute’s
position as a leader in the astronomical
community.
S e rv ic i n g M i s s io n Of f ic e
We facilitate the use of new science instruments
by participating in their development, capturing and
transferring information about their operation
and calibration to the Institute, and coordinating the
re-commissioning of all the instruments following
a servicing mission.
Our first task as a new office in 1995 was to assist with the
introduction of the complex science instruments planned
for the servicing mission in 1997, namely the Near-Infrared
Camera and Multi-Object Spectrograph (NICMOS) and
the Space Telescope Imaging Spectrograph (STIS). Following
their successful integration and commissioning, Office staff
have been working on the final three instruments for
Hubble: the Advanced Camera for Surveys (ACS), to be
flown in December 2000, as well as the Cosmic Origins
Spectrograph (COS) and the Wide Field Camera-3
(WFC-3) planned for July 2003.
During the last year much work was accomplished in
preparing the ground systems for ACS observations. We
organized design and code reviews for all parts of the
calibration pipeline system, including data analysis and
archiving. By the end of the year, most sections were built.
Currently, these sections are under test using data obtained
from the instrument. We have made considerable progress
in the planning and scheduling of scientific operations
with the instrument. The ACS has three different opticalultraviolet cameras and a large selection of filters. All major
instrument modes for single camera operations are completed,
and ready for testing with the instrument. Remaining
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We offer administrative support
for approximately 30 postdoctoral
fellows, who are resident at the
Institute and work with staff
astronomers on a variety of grantfunded research. In addition, we
manage the selection process for our
own Institute Fellowship, supported
by the director’s research fund. This
fellowship, which in many respects
resembles a Hubble Fellowship, is
awarded annually to the applicant
with the best research promise and
plans. Institute Fellows are provided
with a research budget to support
their work. The first Institute Fellow,
Roeland van der Marel, was offered
(and accepted) a position as a regular
Institute tenure-track astronomer in
1998. The second Institute Fellow,
Sally Oey—selected from a field of
over 150 applicants—arrived in
October 1998. Recruiting for the
1999 Institute Fellowship was begun
in the fall of 1998 with the receipt
of 159 applications.
In 1998 the Institute hosted 17
graduate students from around the
world, who came in the latter phases
of their PhD programs to work on
research topics with Institute staff.
We have also begun experimenting
with expanding our support of
beginning graduate students at the
Johns Hopkins University. We assist
with recruiting qualified graduate
students into the Physics & Astronomy
department, and support several
deserving candidates with research
assistantships. In 1998 five “pre-comprehensive” students were admitted
into this program.
We administer the library, which
is one of the jewels of the Institute
and the envy of many of our sister
research institutions. At year’s end, we
had 11,931 volumes in our collection.
In addition to traditional paper
materials, our capabilities for
computer-based research have also
expanded, including a collection
of compact disks (92 titles and 248
disks), and library-mediated access to
26 electronic journals, most of which
are refereed publications. The library
maintains a database of astronomy
research papers. In 1998 approximately 2500 papers were added to
the preprint database, of which 516
were new papers based on Hubble
research. Available electronically over
the World Wide Web, the library
web pages were queried an average of
5820 times per month in 1998.
The director’s research fund is a
vital resource for Institute researchers,
providing financial support for
meritorious research projects not
amenable to other funding mechanisms, and covering research travel
and publication costs for research
papers by Institute staff. To select
research projects, we issue calls for
proposals twice yearly, facilitate the
peer review process, and formulate
recommendations for selections to
the director for his approval. There
were 72 active grants in 1998, with
11 new projects funded in the
r e v i e w s
States. Fellows usually receive offers
of research faculty appointments.
Former and current Hubble Fellows
continue to distinguish themselves,
which was exemplified in 1998 by
Andrea Ghez being awarded the
Newton Lacy Pierce Prize, and
Victoria Kaspi the Annie J. Cannon
Award, by the American Astronomical
Society. Also, 4 out of the 6 astrophysicists selected for 1998 Alfred P.
Sloan Foundation research fellowships
are former Hubble Fellows: Michael
Brown (Caltech), Victoria Kaspi
(MIT), Suzanne Staggs (Princeton),
and Dennis Zaritsky (Santa Cruz).
Full information about the Hubble
Fellow program is available at our
web site. (http://www.stsci.edu/stsci/
27
capabilities and science usage were
evaluated for their impact on operations and data volume. For WFC-3,
initially, we concentrated on the
design for the CCD camera. Then,
following a recommendation of the
Second Decade Study, we helped
support an effort to develop a nearinfrared capability. We will be playing
a major role in the development of
WFC-3. Accordingly, we have been
concentrating on developing the
strength of the WFC-3 team through
internal transfers and external hiring.
We support and conduct strategic studies on topics
and issues related to the future of the Hubble and the
U.S. space program generally.
Our previous accomplishments include the 1990 Strategy Panel study, which
invented COSTAR; the 1993 Future of Space Imaging study, which defined the
advanced camera; and the 1990 Education Initiative in Astronomy study, which
informed the Bahcall committee’s education recommendation. In addition to
the reports of these studies, we have produced other influential reports, such as
the TOPS Report, which presented a program of extrasolar planetary studies, and
HST & Beyond, which defined NGST. In 1998 we continued such leadership
communications, including authoring and illustrating NASA’s brochure explanation
of the extra-solar planet research with the Space Interferometry Mission (SIM).
In 1998 we conducted the first two meetings of the Second Decade Study
for NASA. It will produce a strategic plan for the science program of Hubble
after its final servicing mission. Interim recommendations have included a near
infrared capability for the third version of the Wide Field Camera, and an
increased number of large observing programs.
We conceived and organized a major exhibition of Hubble images to be
displayed at the National Academy of Sciences from April to August, 1999.
Titled “A Universe of Change,” the pictures have been selected to illustrate
variability and evolution in planets, stars, nebulae, galaxies, and the universe as
a whole. The 26 large-format images include some not yet publicly displayed,
from the Hubble Heritage Project.
On the education front, we continued to advocate educational outreach in
NASA’s science program as a whole and Hubble in particular. We conduct the
Exploration in Education (ExInEd) program, which develops print books and
multimedia educational software. ExInEd products are widely distributed via the
Internet, stores, and catalogues, and on diskette, CD-ROM, and in print. In 1998
our “The Hubble Library of Electronic PictureBooks” continued its successfully
distribution through commercial channels. Our software products are also available
over the Internet. (http://www.stsci.edu/ exined/)
The Special Studies Office is collaborating with the Office of Public Outreach
to provide the education program of the Comet Nucleus Tour mission, which
will be launched in 2002.
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Looking ahead, we see exciting
challenges in the recent announcement
of a contingency servicing mission
to Hubble in October 1999, the
primary purpose of which is to replace
the six gyroscopes, upgrade the flight
computer, and replace one Fine
Guidance Sensor. We are currently
preparing plans for the post-mission
observatory checkout and instrument
re-calibration. When those tasks
are completed, on the eve of the
Millennium, we will begin preparations for the next servicing mission in
December 2000, when ACS will be
installed, as well as the cryo-cooler
for NICMOS and an external cooling
system to help cool the detectors in
both ACS and STIS.
Special Studies Office
r e v i e w s
work includes developing a parallel
observing capability. Over the year,
the instrument underwent several
rounds of optical alignment and testing at Ball Aerospace, in Boulder, and
Goddard Space Flight Center, in
Greenbelt. Many aspects of these
activities were designed and led by a
member of the ACS group at the
Institute. The testing and subsequent
selection of the CCDs was also led
by one of the group members.
As the launch date for ACS
approaches, and our development
work draws to a close, we will begin
to focus on operations and user
support. Accordingly, the Science
Support Division has begun developing an ACS group in anticipation of
working with astronomers on ACS
observations and data analysis.
We have begun work on the two
science instruments designated for
the final servicing mission in 2003.
For COS, we embarked on a detailed
review of the expected instrument
operations with the science team from
the University of Colorado, Ball
Aerospace, and Goddard. We have
developed a Design Reference Mission
in which anticipated instrument
29
A d m i n i s t r at io n D i v i s io n
Finance
Grants & Contracts
Human Resources
Staff Support Services
We manage and maintain the facilities
operations, comprising the 120,000
square foot Muller building and a
297-car parking facility.
In 1998 in coordination with our
landlord, the Johns Hopkins University,
we undertook modifications and
enhancements of the Muller building.
We replaced one of four cooling
towers and upgraded the energy
management system. We replaced two
of the four air-conditioning chillers
and initiated a major renovation of
the pavement and roadway at the
main entrance to the building. We
also began renovations and alterations
to facilitate the expansion of the
Office of Public Outreach and the
move of the Hubble flight operations
team to the Institute.
We maintain all Institute financial
records. We prepare and track budgets,
and prepare monthly and annual
financial statements. In addition, we
are responsible for the procurement and
tracking of materials and services
to ensure the smooth operation of
the Institute.
Successful external audits highlighted
the year’s accomplishments. The
audits of our financial statements
and A-133 compliance resulted in
no negative findings. Additionally,
the government waived its review
of our purchasing system for an
unprecedented third year, indicating
its satisfaction.
The conversion to new accounting
software was the outstanding event
of the year. Despite the effort this
entailed, our workflow was not
disrupted, and we continued to
provide timely services. Internally,
monthly cost reports were delivered
within five working days of month
end. We closed the fiscal year and
delivered an accurate financial statement to the auditors with similar
dispatch, allowing an expeditious
audit. Accounts-payable invoices were
turned into checks in fewer than
five days. We have begun using the
new accounting software to prepare
budgets for all grant and contract
proposals, including the Institute’s
FY99 budget. The improved quality
of our planning models and spending
forecasts will improve our resource
management and financial performance.
Working with the Computer and
Network Systems branch, we achieved
cost reductions and workflow improvements by introducing a web-based
purchase-requisition system, which
provides users with status information
about their procurements online. Also,
we consolidated the related functions
of property administration and
procurement in 1998, which streamlines management of equipment
resources.
In 1998 our travel office continued
to provide its customers exceptional
value in their travel spending while
processing a record number of trips.
Some 1200 airline tickets were
issued, up 60% from the previous
year. This increase is due to a general
increase in staff travel and as well as
increased handling of travel arrangements for incoming visitors to various
Institute events.
Grants and Contracts
We prepare proposals, administer grants
and contracts, and award grants for
Hubble research and education activities.
In 1998 we supported the preparation
and submission of 120 new, continuation, and supplemental proposals by
Institute staff for grant and contract
funding. Of this total, we prepared
82 proposals by Institute staff for
Hubble research. As of December 31,
1998, 230 grants and contracts other
than the prime contract were in place,
representing $19.1M in value. During
the year, 67 new awards were received.
Carrying out one of the
Institute’s major community services,
we fund General Observers (GOs)
and Archival Researchers (ARs) to
conduct research based on Hubble
observations. In the process, we
conduct the financial review of submitted budgets, and submit funding
recommendations to the director for
final approval. From inception, we
have awarded $121M for 2678
grants, of which 528 GO/AR grants
worth $18.4M were awarded in
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Building Operations
No aspect of Institute life is untouched by the Administration
Division’s services. So pervasively do our functions transect
the offices and infrastructure, so many are our points of
contact with the staff, that we are keenly aware of the
quiet importance and sensitivity of our roles. We are
committed to customer service excellence, to improving
skills and processes, and to striving towards the highest
standards of performance while seeking ways to save money.
The Administration Division is organized into branches
and groups, which are defined by our major functions and
responsibilities. In 1998 we reorganized, splitting the former
Facilities Branch into a new Staff Support Services group and
a renamed Building Operations and Facilities Planning group.
In addition to the services routinely provided by our
branches and offices, the Administration Division provides
special training for management and staff, commissions
occasional consultant studies of Institute management
issues, and facilitates occasional management retreats to
develop strategy on topics emerging as important for the
Institute’s future. In 1998 we selected a managementconsulting firm to assess the Institute’s organizational
culture, and to make suggestions on a curriculum addressing
the training needs of current and prospective managers.
The firm has begun their assessment by conducting a
diagnostic survey of the entire Institute staff.
Building Operations
Finance
r e v i e w s
We provide business and administrative
services to the Institute in the areas
of accounting, contracts, facilities
management, finance, grant administration,
human resources, procurement, travel,
property administration, and publications.
Looking forward, we anticipate progress
in planning, with Johns Hopkins, a
new building to accommodate housing
needs and reunite all Institute staff.
We foresee major benefits from our
investment in the Cost Point accounting
system, for example, with electronic
timecards and improved management
and budget reports. We anticipate
facilitating a training program to
develop and enhance managerial skills,
as well as instituting recognition and
reward for those who do not wish to
pursue management careers.
31
Human Resources
We provide a wide range of personnel
services to Institute staff and management, including recruitment and
employment, relocation, wage and
salary administration, benefit administration, development and maintenance
of the Equal Employment Opportunity/
Affirmative Action plans, employeemanagement relations, and various
forms of training.
Staff Support Services
We provide a variety of services related
to food, document reproduction, and
building logistics.
Though different in substance, food
and copying services are similar from
the standpoint of management, as
onsite contractors provide both to
the entire Institute staff. To achieve
savings and improve efficiency, we
have combined these functions
under the umbrella of our former
publications group.
In 1998 the serving and dining
areas of the Star Gazer Café, which
provides cafeteria and catering services, were renovated and refurbished.
The Cycle 8 Call for Proposals of
1998 June generated 4,880 individual
copies of various documents and
handbooks, representing 608,920
copy impressions. In total, the Copy
Center produced 5.9 million impressions in 1998.
D ata S y s t e m s D i v i s i o n
We manage and provide technical support
of Hubble science operations, including
pipeline data processing, archive operations,
and distribution of data products to the
Hubble user community. We are also
responsible for the operations, systems
support, maintenance, and long-range planning for all Institute computer systems.
This includes all general purpose, research,
development, operations, and administrative
computer systems required by Institute staff.
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In 1998 our recruitment and employment activities resulted in 75 AURA
hires, including 50 regular and 25
temporary employees. Additionally,
16 students were placed in student
intern positions as part of an ongoing,
affirmative-action effort to provide
training and develop future employment opportunities for women
and minorities.
Institute-wide turnover increased
slightly during the past year from
10.7% to 11.5 %, comparing favorably with national statistics of 13.2%.
In 1998 the Johns Hopkins
Employee Health Plan was added to
the health care coverage options of
our employees. We implemented Life
Works, an employee resource and
referral service. A series of investment
workshops were also held during the
year to assist employees planning for
retirement. We sponsored a series
of successful employee programs,
including the annual Health Fair,
Family Day, United Way campaign,
and Red Cross blood drives.
A pilot employee recognition
program was implemented within the
Administration Division, which will
be evaluated and assessed for the feasibility of Institute-wide implementation.
In 1998 our operations in human
resources remained fully compliant
with regulatory requirements,
resulting in no Equal Employment
Opportunity complaints filed during
the year.
r e v i e w s
1998 alone. We also administer grant
funds for the Initiative to Develop
Education through Astronomy and
Space Sciences (IDEAS) program,
and awarded $600K to 42 approved
proposals in 1998.
In 1998 we defined requirements
for a new web-based software system
to manage the GO/AR grants. The
“Grants Administration Team for
Organizational Re-engineering
(GATOR)” system is being developed with process-improvement funds,
the primary goal being to expedite
the granting process.
In 1998 we engaged in significantly higher levels of new-business
and technology-transfer activities, as
well as more attentive management
of Institute-originated AURA intellectual property. In acknowledgement
of the success of our own grants
system, we were asked to support
the initiation of grant issuance for
SIRTF at the California Institute of
Technology and for AXAF at the
Smithsonian Astrophysical Observatory.
In 1998 the Data Systems Division focused on processing
more data and providing more data to the user community
while reducing costs and improving efficiencies. The pipeline processed more observations with lower shift coverage,
including the 250,000th Hubble observation in October.
Archive operations were improved by segregating and
compressing science and engineering data, and by developing a plan to migrate to magneto-optical storage media. In
addition to such process improvements, we offered expanded
and enhanced services to our users in 1998. The archive
has taken on increasing responsibility for archiving NASA
astrophysics data sets from other missions in the ultraviolet,
optical and near-infrared band-passes. Computer network
access to Hubble data and World-Wide-Web access was
improved, providing more data to users at a lower cost.
Further broadening our scope, the decision was made to
incorporate the Hubble flight operations team into the
Data Systems Division by the year 2000.
33
OSS/PODPS Unified Systems Branch
Archive Branch
Catalog & Surveys Branch
Computing & Network Services Branch
Administration
In 1998 we reduced shift staffing for
routine data production and data
quality assessment by 14% while the
number of observations increased by
45% from the previous year. This cost
saving and efficiency improvement
was enabled by software bug fixes,
design enhancements, and some
procedural changes. The released
effort was applied to other projects,
including preparations for conversion
from DEC’s VMS operating system
to UNIX, and reprocessing flawed
Archive Branch
We are responsible for operating and
enhancing the archive system, delivering
data to users, facilitating search and
retrieval of data from the archive, and
ensuring the scientific integrity and
accuracy of the data archive.
In 1998 the archive ingested a recordhigh volume of data. In December,
the rate was 6 GB/day, a 21% increase
from a year earlier. By the end of the
year, the size of the archive had grown
to 6 terabytes.
A major accomplishment of the
Archive Branch in 1998 was the
development of the multi-mission
archive, which holds—or provides
links to—data from many UV and
optical missions, including Hubble,
IUE, EUVE, ASTRO, as well as the
Digitized Sky Survey and the VLA
radio data from the FIRST survey.
Cross-correlation searches of these
archives are now possible.
We completed several archive reengineering developments. Incoming
data are now compressed and segregated into engineering and science
data, which allows the more popular
data to stay online. Existing data were
retrieved, compressed, and segregated,
such that science data previously
distributed over 578 optical disks is
now stored on just 80 disks. The
Hubble science data are now completely online for immediate access.
Catalog & Surveys Branch
We produce and distribute all-sky
digital images and deep-object catalogues
to support the operations of current
and future ground- and space-based
astronomical observatories, and to
provide a research and educational
resource to the community.
In 1998 a new agreement was negotiated with the Royal Observatory in
Edinburgh and the Anglo-Australian
Observatory to obtain access to their
southern hemisphere, near-infrared,
survey plates. This means we will have
all-sky coverage in three passbands
(J, F, and IV-N). The total number
of available plates is now almost 7500,
of which 60% have now been scanned.
These data are being compressed and
distributed to the community via
collaborating institutions worldwide.
In 1998 our main focus, which
has been constructing the secondgeneration guide star catalogue,
moved from development to operations, and the digitization of sky
survey plates got well underway.
The plate-processing pipelines at
the Institute and the European
Coordinating Facility have completed
over 50% of the plates for the core
program. We also began producing
the database to manage and calibrate
the estimated 10 billion entries that
will ultimately populate the secondgeneration catalogue. The new all-sky
catalogue will be deeper than the old,
and will contain colors and proper
motions. In addition to supporting
Hubble operations, second-generation
guide star catalogue will be used
by the Gemini, VLT, and Galileo
observatories.
In addition to the alreadypublished, 101-volume Digitized
Sky Survey and 18-volume RealSky
products distributed through the
Astronomical Society of the Pacific,
we have participated in the production
of a one- volume version called
RealSky-Classroom, which is being
prepared for high-school education use.
Computing & Network Services
Branch
We support all Institute computing needs.
We provide a variety of technical
assistance to all computer users and
application areas (science, operations,
communications, administration,
databases, and networking) and all
platforms (VMS, UNIX, PC, and
Macintosh). We develop the Institute’s
annual plan to upgrade computer
systems. In the process, we coordinate reviews of system requirements
across the Institute, and suggest
implementation strategies.
Our helpdesk provides a single
point of contact for user support. The
helpdesk system tracked an average
of 1965 calls per month in 1998, up
from 1700 in 1997. The minimum
number of calls tracked per month
was 1718, compared with 1011 the
previous year, for an increase of 41%.
These numbers reflect both increased
customers of the helpdesk system as
well as additional support provided
for all computer platforms. Today,
four out of five Institute divisions and
one office use the helpdesk system
to track requests for and delivery
of services.
In 1998 we moved into the area
of office automation, with the goal of
replacing paper forms with new webbased forms. This has been achieved
for purchase requisitions, which staff
now enter and track via a WorldWide-Web interface.
The increase in the use of
personal computers, both at the
Institute and elsewhere, has led to
difficulties in exchanging documents.
For example, users with UNIX or
VMS workstations on their desktop
were receiving Microsoft Word and
Excel documents as e-mail attachments, which they could not read
without going through a tedious
process, often involving multiple systems. In 1998 we solved this problem
for users with UNIX workstations,
who can now access Windows NT
applications (Word, Excel, PowerPoint,
etc.) and can now read, edit, and
exchange documents in these formats
from their workstations.
Although the total number of
computer systems at the Institute has
not increased, our network bandwidth
requirements had outgrown our
capabilities. A major goal in 1998
was to provide dedicated 10-Mbps
network connections to each desktop,
and this was achieved for 98% of all
systems. Improvements were also made
in 1998 to the Institute’s Internet
connection, providing greater bandwidth as well as improved reliability.
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OSS/PODPS Unified Systems
Branch
We are responsible for pipeline processing of all Hubble data, including
procedural evaluation of data quality.
Also, we support users if they need
real-time interactions with Hubble
during their observations.
data from the archive. Software developed by operations staff to screen
Hubble observations for procedural
problems and failures was adapted to
run in one of our pipelines. As a
result, at the end of the year, we
completed assessing the typical
observation within 3.4 days after it
executed, down by 0.5 days from the
start of the year. We evaluated 85%
of all observations automatically,
with only 15% requiring manual
intervention to verify assessment
accuracy or to add ancillary information. Typically, we provide science
data to the archive, where it is
available to the user online, within 36
hours of the observation.
r e v i e w s
Looking ahead, the Data Systems
Division will continue its work to
transition the Hubble flight operations
team to the Institute. On-the-fly
calibration for the WFPC2 and STIS
instruments will be put into a production mode, which will mean that data
will be calibrated as it is retrieved,
allowing us to store only the raw data.
This will save significant storage space
and ensure up-to-date calibrations for
archive users. Compact disks will be
introduced as an optional medium for
the delivery of data to general observers
and archival researchers. A JAVAbased version of StarViewII, the user
interface to the Hubble archive, will be
released, which will allow operatingsystem-independent access. We will
continue to expand multi-mission
archive holdings, including the ingestion
of FUSE data when it is available,
and will begin to support data system
planning for NGST.
35
Project to Re-Engineer Space
Telescope Observing (PRESTO)
User Support & Observation Development
Planning, Scheduling & Commanding
Transferring Know–How &
Lessons–Learned
We conduct the solicitation and peer
review of the Hubble general observer,
archival research and director’s
discretionary science programs with
maximum efficiency to ensure highest
science value in terms of the merit of
individual observations and overall
program balance.
Efforts in the past couple of years
have streamlined the proposal process
and compressed the timeline between
submission and notification. Most of
the work is now fully electronic. Our
innovations in managing the proposal
process are widely recognized and
admired, and we are actively working
with other observatories to provide
users with consistent and effective
tools, terminology, and process.
Two solicitations and selections
were performed in 1998. First, the
extension of Cycle 7 prompted the
announcement of a special archival
research opportunity, in which 44
proposals were accepted, allocating
$2.8M out of a requested ~$10M of
support. Second, the Cycle 8 general
observer and archival research solicitation and selection was performed.
Cycle 8 saw 1053 proposals submitted,
of which 41 archival research programs worth $2.2M and 254 general
observer programs were accepted.
Looking forward, we plan to continue
investigating peer review dynamics
including those that drive the process to
accept smaller programs in favor of
large programs of equal or higher
scientific importance. For example, we
will look at the role of the sub-discipline
peer review panels in relation to that
of the full Telescope Allocation
Committee, as well as other aspects, in
the process of assuring a well-balanced
Hubble observing program.
User Support and Observation
Development
We provide direct support to Hubble
users to develop their observations
making best use of their allocation
of orbits and most cost-effectively for
the Institute.
Our program coordinators and
contact scientists from the Science
Support Division are the user’s
interface with the Institute during
the period their observations are
being prepared for the planning and
scheduling process. We serve them
with useful tools and professional
advice. Our management goal is to
reduce the overall effort while
providing the user with necessary
support. (In 1998 the Institute
conducted a general assessment of
our user support program, which is
described in the review of the Science
Support Division.)
In 1998 we launched a multi-year
project to re-engineer and modernize
the architecture and methodology of
the software system that translates
astronomer input into the terms and
data items used by the Hubble planning and scheduling process. At
launch, this translation was relatively
straightforward, with the initial,
rather simple, scientific instruments.
However, the installation of more
complex instruments has made it
much more challenging. This problem
has been pressurized by the strong
desire to increase the scheduling
efficiency and otherwise increase
the science return. With the original
architecture of the system overwhelmed, re-engineering was needed.
When it is completed, we will have
a robust, adaptable system that will
serve to the completion of the Hubble
mission, requiring significantly fewer
resources than in the past to operate,
maintain, and enhance.
Today, re-engineered software
packages for observation development
are available to internal users. These
tools are proving themselves, providing critical and accurate feedback about
how well orbits are being utilized.
Observations that used to take days
to prepare for scheduling are now
routinely processed in less than an
hour with the “click of a button”.
Looking ahead, we are preparing to
offer the external users similar
improvements to engage them more
effectively in optimizing their
observations. To this end, we will
integrate the various observationdevelopment programs into a cohesive,
interactive “tool-set”, adapt it to
today’s multi-platform environment,
and offer it to the community.
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Science Program Solicitation & Selection
Many PRESTO accomplishments of the past year reflect a
common theme: we are reaping the benefits of our efforts
to continually improve our processes. Originally founded
as a special project to re-think and re-work observation
planning end-to-end, we remain an organization adept at
seeking and managing change. Our credo: “Simple things
should be simple and hard things possible.” By streamlining
our work and automating routine tasks, we reduce the
resources required to accomplish our goals, and those
savings are available for new and more complex goals.
Accomplishing the entire science program of the nearinfrared camera, NICMOS, before the cryogen ran out and
handling an onboard transmitter failure without science
data loss are two 1998 examples of our ability to deal with
the unexpected without undue stress. This is the result of a
flexible organization dedicated to improving its methods
and tools.
PRESTO staff participated in NGST-related studies
during 1998. While NGST is predicated on a much simpler
operation than Hubble, our experience conducting science
program solicitation and selection, and observation development, will provide valuable support to NGST planning.
Science Program Solicitation
and Selection
To reduce the time and effort
required to conduct the peer review
meetings, we instituted a formal “triage”
process for Cycle 8. We recommended
to the panels that they forego discussion of the proposals graded lowest
in initial reviews. We also continued
to provide incentives to the panels
to encourage the acceptance of highquality larger Hubble proposals, such
as counting half the approved time
against a general pool of orbits rather
than the panel’s allocation.
r e v i e w s
We serve the community by conducting
science program solicitation and selection,
and observation development, planning, and
scheduling, in a manner that maximizes the
returns to science and minimizes the costs.
PRESTO is comprised of two
operational teams (Program
Coordinator, Science Planning and
Scheduling), two science offices
(Science Program Selection, Project
Scientist), and three development
teams (Software Support, Mission
Scheduler Development, Data Base
System Administration).
37
Planning, Scheduling, and
Commanding
We prepare the Hubble observing
program, which involves processing
developed observations, formulating
the long-range observing plan,
generating weekly schedules, and
producing command loads for the
computers onboard Hubble to execute.
Transferring Know-How and
Lessons-Learned
We take extra steps to ensure that our
advances in observing efficiency and
user services are available to other
observatories.
Looking forward, we see growing
importance and mutual benefit in
the transfer of operational know-how
between observatories, particularly in
the form of software and methodology
developed by PRESTO for Hubble
operations.
Science and Engineering
Systems Division
We manage and provide technical support
of Hubble science operations, including
pipeline data processing, archive operations,
and distribution of data products to
the Hubble user community. We are also
responsible for the operations, systems
support, maintenance, and long-range
planning for all Institute computer systems.
This includes all general purpose, research,
development, operations, and administrative
computer systems required by Institute staff.
|
The process of developing, planning,
and scheduling astronomical observations has many factors that are
observatory-independent. The
types of tools required are similar,
although the parameters with which
they work can be quite different.
Thus, it is possible to envision a
common set of tools installed at many
observatories, in similar computing
environments, to perform the various
tasks taking observations from the
proposal stage to execution. This
commonality offers the dual advantages of reducing the learning curve
for observers and allowing observatories
to share software tools, expertise,
methods, and procedures in an effective and efficient manner. All across
the world, observatories are re-engineering the scheduling facet of their
operations, often using systems or
emulating processes that the Institute
pioneered. The Institute is a leader
and a pathfinder by dint of the
complexity of—as well as the investment in—Hubble operations.
To take advantage of this
opportunity, the Institute and the
Advanced Architectures and
Automation Branch of Goddard
Space Flight Center hosted the “The
Workshop on Observing Tools” in
October, 1998. The conference was
well attended, with representatives
from 13 agencies and observatories,
including the United Kingdom
Astronomy Technology Center, the
Space Infrared Telescope Facility, the
Advanced X-Ray Astrophysics Facility,
the European Southern Observatory,
Gemini and the Stratospheric
Observatory for Infrared Astronomy.
There was lively and effective
exchange of ideas at the workshop,
which launched several splinter groups
to focus on restricted areas of known
commonality. At the end of the day,
we discovered that there is little
difference between space-based and
ground-based observing from the
planning and scheduling viewpoint.
r e v i e w s
The job of preparing the Hubble
observing program begins with the
developed observations of individual
users and ends with the command
loads sent up to the telescope for
execution. In the first stage, a longrange plan is developed, which is a
master schedule to establish workflow and set priorities, and informs
users when to prepare for the arrival
of their data. Guided by the longrange plan, weekly schedules are
generated, which take into account
the many physical, scientific, and
programmatic constraints. The goal
is to optimize the weekly schedule
from the standpoint of science
priorities and observing efficiency
(time on target) while assuring the
health and safety of the spacecraft.
The role of the Institute in
Hubble spacecraft operations used
to end with delivery to NASA of the
weekly science schedule. In 1997,
our role was expanded to include
performing mission scheduling, by
integrating spacecraft housekeeping
functions with science operations. In
1998 our role was further expanded
to include interacting with Goddard
Space Flight Center to obtain
communications contacts and ephemeris
data products. The integration of
all the planning, scheduling, and
commanding tasks has made the
whole process easier and more straightforward, and has been accomplished
with no increase in staff.
One measure of the success of the
PRESTO program of improvements
is the ever-rising observing efficiency,
which means getting more value out
of Hubble while lowering the costs
of operating it.
39
We work closely with operations staff at Goddard Space
Flight Center and the Institute to ensure the proper
functioning of flight and ground systems that are used to
operate Hubble. When something goes wrong or changes,
we try to understand what happened and make appropriate
changes in parameters, operational procedures, or software.
We also revise or enhance operational systems to accommodate new instruments, increase observatory capabilities
for users, and reduce long-term costs for operations and
maintenance. Our experience and expertise with Hubble
transfers usefully to other missions. We are deeply involved
with planning the Next Generation Space Telescope (NGST),
and are supplying important services and systems to
other missions, notably the Far Ultraviolet Spectroscopic
Explorer (FUSE) and the Space Infra-Red Telescope
Facility (SIRTF).
Assuring Hubble Science Operations
Improving Operations Systems
Supporting NGST & Other Missions
Assuring Hubble Science
Operations
We quickly respond to problems that
can compromise the effectiveness of
Hubble observations, and work with
operations staff to resolve them. We also
carry out advance work necessary to get
ready for operations of new instruments,
working with the developers as they
design, build, and test new instruments.
We continually improve the software systems used to support Hubble observing.
We completed major enhancements
to several software systems in 1998.
The highlight was the debut of
the new guide star system. We also
wish to mention important software improvements in scheduling,
archiving and calibration, and
managing engineering data, including
astrometry data.
The original Guide Star Selection
System was built in the mid-1980s
and had become obsolete. We built
the New Guide Star System using
modern software techniques, and
cut the system size in half. We also
incorporated new features to facilitate maintenance, improve the user
interface, and increase performance.
NASA bestowed a Quality and
Process Improvement Award on the
guide star implementation team.
We performed a major enhancement to the scheduling-system
software that places instrument
transitions into the weekly schedule.
The performance of this software had
degraded due to the large volume of
programs using short exposures and
multiple instruments. The new
version of this software is more than
ten times faster than the old, which
has permitted substantial compression
of the scheduling timeline for Hubble.
In archiving and calibration, we
completed several projects to expand
capacity, improve user performance,
ensure optimal calibrations, and
facilitate data distribution. We
participated in the “secondary load”
of the archive, which substantially
compressed the data, allowing the
entire science archive to be once
again stored on-line. The first phase
of an “on-the-fly” calibration system
has been completed. This will allow
us to keep only raw data in the archive,
rather than raw and calibrated data
as we do presently. The system will
apply the best available calibration
to the raw data whenever they are
retrieved from the archive, prior to
being delivered to the user. This
saves space and also ensures the user
of the best available calibration at the
time the data are retrieved. Finally, we
completed a major enhancement to
the system that supports bulk distribution of Hubble data to the mirror
sites at the European Coordinating
Facility and the Canadian Astronomical
Data Center.
We have been involved in several
efforts at Goddard Space Flight
Center to lower the cost of Hubble
operations by simplifying systems and
improving efficiency. For example,
early in 1998 we began processing
astrometry data in the Institute’s
calibration pipeline. Astrometry data
from the fine guidance systems flows
in the engineering-data stream rather
than the science-data stream. The new
system has allowed retirement of the
original engineering-data processing
system located at Goddard. We also
have been helping with the testing
of a modernized system to be used
for monitoring Hubble, which will
be moved to the Institute when the
flight operations team moves here.
We have been working with staff
in the Administration Division to
develop a new grants administration
system. This system will allow astronomers to submit grant applications
electronically, and will also automate
many of the manual steps currently
required of the Institute’s grant
administration staff.
And last, but not least, we
completed testing all of the Institute’s
operational systems to ensure that we
will not suffer from any “Y2K” bugs.
Looking forward, we expect to
make further enhancements to our
current systems to improve the cost
effectiveness of Hubble operations.
and observation scheduling, as well
as systems engineering support.
The SIRTF project has adopted two
systems we developed: our calibration
pipeline executive system and the
grants administration system.
Looking ahead, our primary new
challenge in the coming period will be
leadership of a further definition of
NGST operations concepts.
Supporting NGST and Other
Missions
We apply our expertise in science
system engineering, gained over many
years with Hubble, to future missions,
including NGST.
We actively support several definition activities for NGST. Our staff
work closely with astronomers in the
community to develop and refine
the scientific rationale and expected
science program for the telescope.
Similarly, we work closely with NASA
and industry engineers to investigate
possible designs for the telescope,
and to address the most pressing
technological issues in building it.
One of the challenges for the
Institute will be to operate NGST
with a smaller budget than Hubble.
During the past year we carried out
our initial studies of NGST operations concepts and made our first
ground-up estimate for the costs of
NGST operations.
Our system engineers coordinated
the delivery of a suite of science
operations systems and services for
the FUSE, which is being developed
at Johns Hopkins University for
launch in May 1999. The Institute
has provided the mission with
pipeline data processing, data archiving,
software tools for proposal processing
|
Looking ahead, our priorities will be
the servicing mission this October, and
continued preparation of the ground
system for the new instrumentation to
be installed in the 2000
servicing mission.
Improving Operations Systems
r e v i e w s
In 1998 relatively few spacecraft or
instrument anomalies occurred as
compared with the previous year. In
the spring, the loss of one of the highdata-rate transmitters did present an
operational issue. One of our systems
engineers served on the failure review
board and subsequently coordinated
the necessary fixes in the scheduling
systems. In the end, this failure has
had no substantive impact on Hubble
productivity, and the transmitter unit
will be replaced in the next servicing
mission. In October, a gyro failure
was accommodated without impact
to the science program. Perhaps the
most important operational issue of
1998 was the exhaustion of the
solid-nitrogen cryogen in the nearinfrared camera, NICMOS. Our
engineering staff monitored NICMOS
closely throughout the year, and
accurately predicted the cryogenexhaustion date, which was needed
to successfully finish the entire
NICMOS science program while the
detectors were still cold. We also led
the group that developed the monitoring program for NICMOS as it
warmed up, and are using those
data to predict performance when
the mechanical cryo-cooler is
installed during the December 2000
servicing mission.
There has been a lot of activity
in preparation for the next servicing
missions, in October of 1999 and
late in 2000. Most of the detailed
command procedures necessary to
operate the Advanced Camera for
Surveys (ACS) have been developed
and tested with the instrument.
Requirements have also been provided
for the necessary scheduling software
changes, and these are now largely
implemented and tested. Changes
have been made to the data processing
pipeline and the archive to handle
the large volume of ACS data, and
these changes are being tested with
data from the instrument. A second
cooling system, for the Hubble axial
instrument compartment, will also
be installed in 2000, and our engineers are involved in defining ground
tests, operational requirements, and
implementation plans to ensure that
the coolers do not have an adverse
effect on the telescope.
41
Science Support Division
NICMOS Group
Spectrographs Group
Observatory Science Group
Science Software Group
Looking forward, the Science Support
Division will contribute its experience
and lessons from the user support
assessment to the planning process for
NGST, while continuing to provide
Hubble users with effective and
efficient technical support.
WFPC2 Group
We are responsible for the optimal
utilization of the WFPC2 instrument.
WFPC2 continued to operate
flawlessly throughout 1998. Since it
is now in its fifth year of operation,
we have made significant efforts to
test for long-term changes in its
performance. The long-term photometric stability appears to be excellent, with fluctuations of two percent
or less in most filters between 1994
and 1998. Both the number of hot
pixels, and the low-level dark current
show modest increases due to radiation
damage, but without significant
impact on science observations.
A large effort was devoted to
studying the so-called “long versus
short” exposure effect. The effect gains
its name from early evidence that
long-duration exposures of a star
tended to give brighter magnitudes
than shorter exposures, as though a
fraction of the target signal is lost,
where the fraction increases for fainter
signals. This effect appears to be
the result of a non-linearity of the
detector and signal chain. A simple
formula has been developed to
correct the effect to an accuracy of
a few percent for faint sources.
An increasingly important
Hubble imaging technique is using
small position offsets or “dithers” to
allow removal of detector artifacts
and improve sampling of the image.
NICMOS Group
We are responsible for the optimal
utilization of the NICMOS instrument.
NICMOS has had a short, but productive life to date. Due to cryogen
exhaustion, the last science observation
was executed on 18 December 1998.
The anticipated dewar warm-up
started on 3 January 1999, and the
instrument was placed into a safe
configuration, where it will be held
until the new mechanical cooling
system is installed during the servicing
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WFPC2 Group
Most of the Science Support Division is organized into
groups according to the suite of currently existing and
planned Hubble scientific instruments. In 1998 the
instrument groups consisted of one for the optical camera,
WFPC2; one for the near-infrared camera, NICMOS; one
for the spectrographs, STIS, GHRS, and FOS; and one for
observatory science, including the European camera, FOC,
and the fine guidance systems, FGS. A new group has been
formed to prepare to support the Advanced Camera for
Surveys (ACS), which will be installed during a servicing
mission late in the year 2000; this group currently works
closely with the Servicing Mission Office, as described in
that office’s review. Two groups in the Science Support
Division are not organized by instrument. One develops
the science software tools needed to reduce and analyze
data from Hubble instruments. The other consists of data
analysts to aid astronomers in their research. The Science
Support Division, along with the Servicing Mission Office,
hosts a large number of the Institute’s scientists and much of
its instrumentation expertise. The Division will increasingly
begin to support NGST instrument planning activities.
important role that timely, highquality calibration plays for the
Hubble user community. While our
documentation was highly rated, the
survey exposed the need for a better
key or guide to it, so that finding
specific information would be easier.
In the second stage of our user
support assessment, we formed three
focus groups to help interpret the
survey and to study various aspects
of user support in more detail. The
groups, consisting of both Institute
and outside astronomers, focused on
proposal processing and scheduling;
calibration, analysis, and archival
support; and software support for
users. The final recommendations,
melding survey and focus group
results, include: increase support
for infrared observations; improve
organization and indexing of paper
and web-based documentation;
improve proposal processing software
tools; reduce paper products and
data tapes; outsource calibration of
infrequently used modes; consolidate
support of redundant instrument
modes; reduce contact scientist support
for users of mature instruments;
simplify end-to-end proposal processing
effort; and reduce support for
certain software packages. These
recommendations will be implemented
Institute-wide.
r e v i e w s
We ensure that Hubble observers use the
science instruments to maximum effectiveness
by providing direct technical advice in
developing observations and interpreting
data, and by calibrating and characterizing
the scientific instruments.
The Science Support Division
supports Hubble users in two modes,
proactive and reactive. We assign a
single scientist to be the primary
scientific contact for each approved
science program. These proactive
contact scientists are responsible for
aiding the principal investigator
teams in strategies for carrying out
their programs, and for answering
questions about the execution of the
program and how best to analyze the
data. Our help desk reacts, quickly
answering all manner of questions
from the wider community, about
past, present, and future instruments,
or about data analysis software and
techniques, proposal preparation, or
documentation. With help-desksupport software, we track incoming
questions accurately and efficiently,
and find that practically all queries
are answered within two working
days, most within a few hours.
Supplementing the contact scientists
and help desk, data analysts are
available to provide hands-on data
reduction and analysis support to
any and all observers, local, visiting,
and remote.
The Science Support Division
and PRESTO together advise the
Director’s Office in resolving major
proposal change requests, resolving
target duplication issues, and achieving
closure on observation problem
reports, which sometimes involves
rescheduling failed observations.
In May 1998 the Institute undertook a general assessment of our user
support program, to identify areas for
improvement, services most valued
by users, and areas where savings
might be made with least impact to
the community. In the first stage of
this assessment, a web-based user
survey was advertised via e-mail.
Approximately 350 individuals filled
out the survey, roughly twice as many
as with previous, more specialized
surveys. The survey reaffirmed the
43
mission late in the year 2000. We
monitored NICMOS closely during
its warm-up period to learn what to
expect when the detectors operate in
the new temperature regime of the
planned mechanical cooling system.
We expect the instrument to regain
all basic science capabilities.
Executing the full science
program of NICMOS despite the
thermal leak was a great achievement.
It involved incisive problem assessment, accurate prediction of when
the cryogen would be gone, solicitation of additional observing programs,
and strategically re-crafting Hubble
scheduling priorities. During the
intensive period of NICMOS priority
scheduling, up to 50% of Hubble
observations were carried out with
NICMOS. In the end, a total of 3,340
orbits of prime science were executed
with this instrument, and 592 orbits
were obtained in parallel mode.
The lack of parfocality between
the three NICMOS cameras, another
consequence of the dewar anomaly,
was addressed by scheduling widefield (Camera 3) observations in
campaign periods during which
Hubble’s secondary mirror was
moved to achieve focus. The first
such campaign in January 1998,
with a duration of about four weeks,
was successful, and a second similar
campaign was conducted in June.
Several of these observations involved
detailed infrared views of the Hubble
Deep Field North. Observations of
the southern counterpart, Hubble
Deep Field South, were carried out
in October 1998. These images show
light from distant galaxies shifted
from the visible into the infrared,
and probe the dusty centers of
foreground galaxies of moderate
redshift, revealing stars and structure
not seen in optical imagery.
Spectrographs Group
We are responsible for the optimal
utilization of the spectrographs, STIS
and FOS.
In 1998 we successfully brought the
Space Telescope Imaging Spectrograph
(STIS) into routine operation as a
mature instrument, guiding users
through the first fully operational
year of observing. Nearly all calibration reference files are now based on
in-orbit data, and the data calibration
pipeline provides reliable and robust
processing of all STIS data. STIS
performance has been excellent. It
has good basic stability, including
focus, flux repeatability, acquisition
accuracy, flat fields, internal geometry,
and mechanism reliability. After a
period of lower usage while the
NICMOS science program was expedited, the percentage of observations
with STIS will increase significantly
in 1999. Faint Object Spectrograph
(FOS) calibration was also improved.
The Hubble Deep Field program
has been a beneficial undertaking
from several perspectives, notably
including the improved instrument
understanding gained from the
intensive efforts to release a data
set of the highest possible quality.
The Hubble Deep Field South data
released to the public in November
1998 included extensive STIS images
of the prime and flanking fields and
deep spectroscopic observations of
the centered quasar. Our work
calibrating and reducing these observations resulted in improved dark
subtraction, methodologies for
dealing with hot pixels, improved
geometric distortion solutions for the
imaging modes, low-order imaging
flats for all detectors, and techniques
for dealing with amplifier-ringing
artifacts around hot pixels. In addition, software for optimal extraction
of spectra and optimal splicing of
overlapping spectra were developed.
Such techniques, applicable not only
for STIS but for other present and
future instruments as well, will
benefit all Hubble users in the form
of improved algorithms, better data
analysis software, and improved
understanding of the instruments.
Observatory Science Group
We maintain the Hubble focal plane
model, support the use of the Fine
Guidance Sensors (FGSs) as astrometry
science instruments, and provide
support for Faint Object Camera
(FOC) observations.
Maintaining and updating the focal
plane model involves analyzing
pointing errors in target acquisitions,
which reveal the relative alignments
of the instruments and the FGSs.
The analysis either verifies that the
positions employed are of sufficient
accuracy to support the science
program, or produces changes in the
positions to be incorporated in the
flight software.
In 1998 while FGS 3 was
maintained and calibrated as the
astrometric science instrument, we
were monitoring the performance
of the newly-refurbished FGS 1R,
which became outstanding as it
stabilized after installation in the
second servicing mission. It can
resolve binary systems with separations
as small as 7 milliseconds of arc, a
dramatic improvement over FGS 3.
Also, the stability of fringes is six
times higher in FGS 1R as compared
with FGS 3. Consequently, FGS 1R
was designated the astrometric science
instrument for the Cycle 8 Hubble
science program.
We contributed to NGST studies
in three areas. First, we examined the
statistics of Hubble observing mode
usage and reported their implications
for the NGST design reference
mission. Second, we used radiative
transfer models to evaluate the
practicality of passively cooling the
NGST instrument module to about
30 Kelvins. Third, we completed a
wavelength-dependent study of stray
light with scattering from various
levels of assumed contamination on
the optics. This effort produced a
parametric model of the stray light
expected at various pointings from
the integrated effects of thermallyemitted photons from the sunshade
inner surface, off-axis galactic light,
and off-axis zodiacal light.
Science Software Group
We provide the tools needed to reduce
and analyze data from existing and
future Hubble instruments. These
software packages are available to the
community as part of the data analysis
system, and a subset forms the core of
the standard calibration pipeline for
all instruments.
In 1998 we improved the calibration
pipeline, incorporating a new system
for FGS science data, introducing
the baseline version of the ACS calibration package, and enhancing the
pipelines for the recently installed
instruments, STIS and NICMOS,
which now routinely produce highquality calibrated data for observers.
Based on the Hubble Deep Field
experience, we added two dataanalysis tasks to the science software
available to the community: the
dither task and the spectrum-splicer
task. The dither task uses sophisticated
algorithms to combine many images
to produce a clean, higher-resolution
composite image, These tools align
the dithered images, and combine
them while removing detector artifacts,
geometric distortions, and rotations
(a process called “drizzling”). A
detailed, hands-on guide for use of
this software was released, providing
detailed examples for combining
dithered images taken with the
Hubble cameras for a range of
targets. Work is underway to add
more capabilities to the dither software, including the ability to mosaic
multiple-detector images onto a
single drizzled image, and the removal
of time-variable artifacts (such as
cosmic ray events) from images.
Looking to the future, we have begun
an important project to replace the
command language used to control
data-analysis tasks. Our approach
preserves the investment in the existing
software, while taking a major step
toward the long-term goal of opening
up the current data-analysis environment, making it more powerful and
easier to use for both astronomers and
programmers.