Fundamental Physics Program
onboard Space Shuttle and Planned
for International Space Station
Mark C. Lee
NASA Exploration Systems Mission Directorate
Fundamental Physics Program at NASA
• Physics And Chemistry Experiments (PACE)
• Fundamental Physics Experiments and PACE
onboard Spacelab/STS
• Fundamental Physics Investigations Planned for
ISS
15 Physics And Chemistry Experiments (PACE)
PACE…
Timeline
• Five Contemporary Fundamental Physics
NRAs for Spacelabs and ISS
– 1994/1996/2000/2001/2002
• FP, PACE and Other Experiments Executed
onboard Spacelab/STS
– LPE/CHeX/ZENO/CVX;
– DDM/DPM/STDCE;
– AADSF/CGF;IDGE;
– SSCE/DCE;PHaSE
• Four Microgravity Sciences Disciplines
– Fluids/Materials/Combustion/Biotechnology
– Fundamental Physics?
David Lee – Delivery from Heaven
Timeline continues…
• Formation of FP Discipline Working Group –
late 1996
• Publication of Fundamental Physics in Space
Roadmap (Led by Ulf Israelsson)
William Phillips – More from…
Delivery of Confined Helium Experiment (CHeX)
Wolfgang Ketterle – and More and More…
Timeline continues…
• 71 Distinguished FP Principal Investigators
as of July 12, 2002, including 10 ISS Flight
Investigations
• But…
• No resolution to the originally Selected PACE
Program Satellite Test of Equivalence
Principle (STEP)
Satellite Test of Equivalence Principle (STEP)
US$28M Pre-Phase A
External Peer-Review Recommendations on STEP
1983 - Selected by Physics and Chemistry Experiments (PACE) Panel
1988 - Reviewed by Space Study Board of National Research Council in SPACE SCIENCE IN THE
TWENTY-FIRST CENTURY: IMPERATIVES FOR THE DECADES 1995 TO 2015 for
FUNDAMENTAL PHYSICS AND CHEMISTRY.
1990 - Reviewed by NASA’s ad hoc Committee on Gravitation Physics and Astronomy (Chair: I.
Shapiro). The Committee strongly urged NASA continuing funding of laboratory engineering
development of STEP in the next three years.
1990 - Assessment by an ESA ad hoc Committee on Fundamental Physics and Experiments in Space
(Chair: F. Fuligni). STEP was ranked the highest priority among five proposals for fundamental
physics experiments in space submitted in response to ESA’s M2 Mission announcement.
1993 - Assessment of the ESA ad hoc Fundamental Physics Working Group (Chair: J. Blaser). STEP
was ranked number one priority out of 16 proposals for fundamental physics submitted in response to
ESA’s M3 Mission announcement.
1994 - Reviewed by NASA QuickSTEP ad hoc Science Review Committee (Chair: Clifford Will). The
Committee reported that “...STEP significantly strengthening the foundation of general relativity... and
... is technologically feasible, with only modest improvements from current technology needed.”
1996 - Comparatively reviewed of NASA’s MiniSTEP, CNES’s GEOSTEP and ASI’s GG by ESA
Fundamental Physics Advisory Group (FPAG) (Chair: M. Jacob). FPAG strongly recommended
MiniSTEP over the other two candidate experiments as “the scientifically most important mission in
fundamental physics.”
Recruiting Joseph Taylor
Blue Ribbon Peer-Review Panel on STEP
1998 - NRA-96-HEDS-03 Blue Ribbon PeerReview Panel on the FP Proposals: “The panel
strongly and unanimously recommends this
experiment (STEP) for flight development”.
Blue Ribbon Panel Member
Joseph Taylor – Chair
Robert Richardson
Thibault Damour
Kip Thorne
Eric Adelberger
Riley Newman
NASA Administrator’s review
Microgravity Fundamental Physics Program were
reviewed twice in person by Mr. Daniel Goldin, the
NASA Administrator
1. 1998 - With Joseph Taylor, Thibault Damour,
Arnauld Nicogossian and Mark Lee
2. 2001 - With NASA Chief Scientist Kathie Olsen
and Mark Lee – leading to an article intended for
Physics Today
Mr. Goldin’s Physics Today’s Article
The Laboratory of Space:
Fundamental Physics Research at NASA
Daniel S. Goldin* and Nicholas Bigelow**
* Daniel S. Goldin is the Administrator, National Aeronautics
and Space Administration.
** Nicholas Bigelow is Lee A. DuBridge Professor of Physics at the
University of Rochester and the Chairperson of NASA's
Fundamental Physics Discipline Working Group.
Submitted to Physics Today prior to November 17, 2001
Declined due to his resignation as NASA’s Administrator
LTMPF Common - Facility
LTMPF is a state-of-the-art facility for
long-duration science investigations
whose objectives can only be achieved
in microgravity & at low temperature
• First launch scheduled for
November 2005
• External site on ISS’s JEM-EF
• STS launch & retrieval
• 2 Cryo Inserts; multiple experiments
• Cryogen lifetime ~ 5 months
• Environments monitored
• Extensive inheritance
• Operating lifetime: 5 missions
• Teaming between Ball, Design_Net,
Low-Temperature science
community, & JPL
DYNAMX
Robert Duncan, University of New Mexico
How do out-of-equilibrium conditions modify the nature of continuous phase
transitions?--- Provide a bridge between theory and real systems
Why:
The superfluid transition in 4He has been the model
system for testing the fundamental theory of phase
transition. When driven away from equilibrium, the
superfluid transition evolves from a simple critical point
into a fascinating and complex nonlinear region, where
the onset of macroscopic quantum order is masked by
Earth’s gravity.
Cell
How:
A new type of exceptionally stable high-resolution
thermometers will be used to measure the thermal
profile near the normal to superfluid interface while
a small heat flux Q travels through the helium. The
superfluid interface will be advanced slowly though
the cell, and the temperature profile behind the
interface will be recorded by three temperature
probes imbedded in the sample cell’s side walls.
Impact:
The results will provide conclusive experimental tests
of the most advanced existing theories describing
dynamical phase changes. These results will impact
the understanding of dynamical critical phenomena,
quantum liquids, quantum phase fluctuations, and
closely related fields such as cosmology and
quantum statistics.
Cooling
stage
High resolution
Thermometers
A bold attempt to explore a new area of critical
phenomena, the study of non-equilibrium dynamics
near criticality.
Peter K. Day, William A. Moeur, Steven S.
McCready, Dmitri A. Sergatskov, Feng-Chuan Liu, and Robert
V. Duncan, Phys. Rev. Lett. 81, 2474, 1998.
RV Duncan, AV Babkin, DA Sergatskov, STP Boyd, TD
McCarson, PK Day, J. Low Temp. Phys. 121, 643, 2000.
Figure Caption
FP2
Final Peer Review Date: 1999
FHA: May, 2005
MISTE
Martin Barmatz, Jet Propulsion Laboratory
Why MISTE in Space? --- Advance understanding of critical phenomena
Why:
The most precise theoretical calculations of
critical behavior are for a liquid-gas critical point.
The huge compressibility associated with the
earth’s gravitational field limits measurements in
near-critical fluids. This difficulty can only be
overcome by performing critical-point
measurements in a microgravity environment.
How:
The MISTE flight experiment will be performed
on the LTMPF/ISS during a 4.5 month period.
This study will conduct high precision
pressure, density and temperature
measurements as well as heat capacity at
constant volume and compressibility
measurements throughout the critical region of
Helium-3. Measurements will specifically be
performed along the paths of constant critical
density, constant critical temperature and
coexistence curve.
Impact:
These results can be used to self-consistently test
theoretical equation-of-state predictions for universal
critical amplitude ratios and relations between critical
exponents. These asymptotic and crossover models
apply to all simple fluids and fluid mixtures and their
unambiguous validation (or modification) will provide
a major advancement in condensed matter physics
and engineering.
The need for a long-duration low-temperature
environment in microgravity is particularly
compelling for MISTE.
Prototype MISTE flight cell
FP 3
Final Peer Review Date: 1999
FHA: May, May, 2005
CQ
David Goodstein, California Institute of Technology
Why measure CQ in space? ---Expand understanding of non-equilibrium systems
Why:
The CQ experiment will extend the DYNAMX
experiment into the Superfluid Phase, where a
measurement of the heat capacity at constant Q
(CQ) should answer the most important scientific
issues in that regime.
How:
Precision measurements of the heat capacity
of helium will be taken just below the helium
superfluid - normal fluid transition by applying
small pulses of heat while a constant heat is
passed through the DYNAMX thermal
conductivity cell. The temperature rise caused
by the heat pulses will be measured by the
three temperature probes imbedded in the
sample cell’s side walls.
Impact:
The discovery of an infinitely large heat capacity
always has a dramatic, transforming effect in physics.
Just such an effect has been predicted theoretically in
the conditions of the CQ experiment. The theory
cannot be tested in the laboratory, but verification
might be possible in gravity-free conditions. CQ will
be a no hardware or engineering cost extension of
the DYNAMX experiment.
Ground experimental results showing the
enhancement in the heat capacity with applied heat
current compared to theory and zero heat flow.
CQ was selected from the OBPR-00 NRA
Weichman, Harter and Goodstein, Rev. Mod. Phys. 73, 1, 2001.
FP 4
Final Peer Review Date: 2002
FHA: May, 2005
COEX
Inseob Hahn, Jet Propulsion Laboratory
Why COEX in microgravity? --- Advance understanding of phase transition
Why:
Experimental studies of phase transition near
the liquid-gas critical point has been severely
affected by gravity. The confirmation and test of
fundamental relationship between critical
exponents and amplitudes is difficult unless
experimental quantities are simultaneously
obtained in a same measurement condition.
How:
LTMPF/ISS and MISTE hardware are used to
obtain the coexistence curve of helium-3 fluid
near the liquid-gas critical point in microgravity
condition. The density of the sample is
manipulated in-situ low temperature gas
handling system. The temperature is
measured by the high-resolution thermometer.
The coexistence boundary will be determined
by detecting the specific heat anomaly at the
transition temperature at different densities
throughout the critical region.
Impact:
We shall test the scaling hypothesis and equation-ofstate model predictions with unprecedented accuracy
by combining with the data from MISTE experiment.
Space cryogenic sensors (temperature, density,
pressure) and flight software technologies shall
significantly benefit other fundamental physics
experiments.
The MISTE hardware that will be used for the COEX
measurements.
FP5
Final Peer Review Date: 2002
FHA: May, 2005
COEX was selected from the OBPR-00 NRA
SUMO
John Lipa, Stanford University
Why a Superconducting Oscillator in Space? --- Test Special and General Relativity
Why:
The ultra-stable frequency from a superconducting
microwave oscillator probes new science because it
depends in a unique way on the underlying constants
of fundamental physics. Additionally, the SUMO
oscillator provides a low noise signal to improve the
performance for atomic clock experiments on the ISS.
How:
SUMO is developing a new generation of
superconducting microwave cavities that are
much less sensitive to acceleration than earlier
models. Two superconducting cavities will be
mounted at right angles to each other for
Special Relativity tests, and comparison with
an atomic clock gives additional tests of
Special and General Relativity. Dependence of
the frequencies on orientation and orbital
velocity vector of ISS will lead to tests of
deviations from the Standard Model of matter.
Impact:
Provides new tests of three basic theories of physics:
Special Relativity, General Relativity, and the
Standard Model of matter. Also, interconnection with
ISS atomic clock experiment RACE improves both
science and atomic clock performance.
SUMO will be a landmark experiment. It will not
only allow scientists to test the fundamental
theories of physics with unsurpassed precision,
but will also advance the performance of our
most accurate clocks.
Superconducting cavity design for reduced
acceleration sensitivity
FP 6
Final Peer Review Date: 2004
FHA: March, 2007
“Testing Relativity with clocks on Space Station”, J.A. Lipa et al,
Proceedings, 2nd Pan Pacific Basin Workshop on Microgravity
Sciences, Pasadena, CA May 1-4, 2001.
BEST
Guenter Ahlers, University of California and Santa Barbara
Feng-Chuan Liu, Jet Propulsion Laboratory
Why BEST in space? --- Comprehensive understanding of the dynamic finite-size scaling
Why:
The dynamic finite-size scaling and the effects of
boundaries on transport properties of a fluid are of
great scientific and industrial importance, yet have
not been well studied. In order to achieve the best
and comprehensive understanding, a large range of
finite-size systems is required. Due to the gravity
smearing effect on the ground, such large range can
only be achieved in space.
Capillary plate with 2dimensional slots (5 X 50mm)
How:
Measure the thermal conductivity of liquid helium
near the superfluid transition at various pressures
with cylindrical and rectangular confinement of
various characteristic sizes in a combination of
ground (< 10 mm) and flight (~50 mm) experiments.
Two types of DC SQUID-based superconducting
devices are employed to achieve high-resolution
measurements: the High-Resolution Thermometer
(HRT) for extreme temperature resolution (< 1 nanoKelvin) and the superconducting pressure gauge for
extreme pressure resolution (< 1 nano-Bar).
Impact:
Transport properties in finite systems have a broad
range of relevance which transcends the helium
problem. They are important, for instance, also to
electrical conduction in thin wires which is highly
relevant in mesoscopic systems and numerous
applications.
Capillary plate with 1-dimensional cylindrical
holes (50mm)
FP 7
Final Peer Review Date: 2004
FHA: March, 2007
SCR panel statement:
“BEST will make a landmark contribution to NASA’s
Low Temperature and Condensed Matter Physics
campaign.”
Primary Atomic Reference Clock in Space
Donald Sullivan, National Institute of Science and Technology
As the Laser Cooling Pathfinder PARCS will improve timekeeping while testing
fundamental tenets of Einstein’s theories
Why:
Atomic energy levels are among the most
reproducible phenomena in Nature and are also
the basis for atomic clocks. Such clocks make
fertile testing grounds for physics beyond the
levels of current understanding while also
supporting standards needed for commerce,
high speed communications, and navigation.
How:
PARCS involves frequency comparisons between highperformance atomic clocks on the ISS and on the
ground. Atoms cooled to a millionth of a degree above
absolute zero float through a microwave interrogation
region to measure the transition used to define the
base unit of time, the second. Microgravity allows long
interaction times reducing effects which limit the
performance of ground clocks.
Impact:
PARCS will set new limits on our understanding of
gravity as it relates to the nature of time and space
while realizing the world’s most accurate clock.
Techniques and capabilities developed for PARCS
enable future science measurements using laser
cooling and space atomic clock.
Artist rendition of laser-cooled cesium
clock in space.
From RDR panel report: “Second, the Panel
concluded that the scientific motivation for the
experiment remains excellent and the need for
microgravity and the access to space is
compelling. The Panel continues to fully and
enthusiastically endorse the science that drives
this mission…”
“PARCS: a Primary Atomic Reference Clock in Space,” Proceedings of
the 1999 IEEE International Frequency Control Symposium, p. 141
(1999).
Rubidium Atomic Clock Experiment
Kurt Gibble, Penn State University
The Ultimate Stability and Accuracy in a space-based Atomic Clock
Why:
•Advance atomic clock science to enable
measurements with accuracy of 1 part in 1017.
•Significantly improve the classic clock tests of
general relativity and search for violation
predicted by string theory.
•Distribute the highest accuracy time and
frequency from the ISS.
How:
• Laser-cooled atomic clock based on high
density Rubidium atomic beams. Much less noise
in the clock signal than in Cesium.
•Circumvents the large shift of the tick rate due to
Cs collisions that is inherent to all laser-cooled Cs
clocks. High density beams lead to clock
instabilities in Cs.
• Novel double clock configuration employed to
reduce the cost and complexity of the electronic
oscillator that excites the atoms.
Impact:
•RACE will explore the limits of relativity, where modern
grand unified theories of the cosmos predict a
breakdown of Einstein’s theory of gravitation.
•RACE and SUMO are currently scheduled to be on the
ISS simultaneously. Comparisons of these two clock
experiments will improve the relativity test of the
anisotropy of the speed of light by over a factor of 1
million.
Dual Clock Concept launches cold Rb atoms (in
blue) opposite directions alternately to improve clock
stability and reliability
“The SCR panel identifies RACE as being of very high
intrinsic value to the scientific community and that the
anticipated improvements should be classified as
dramatic and as timeless.”
Condensate Laboratory Aboard the Space Station
William Phillips, National Institute of Standards and Technology
CLASS will advance our understanding of the organizing principles of nature by
observing free evolution of macroscopic quantum systems.
Investigation Selected from 00NRA but does not have funding
Why:
The study of BEC has been one of the most
exciting areas in atomic physics over the past
five years. Many of the experiments that have
been performed to date have been significantly
affected by gravity.
How:
Laser cooling techniques are used to pre-cool
a sample of rubidium atoms to temperatures a
few millionths of a degree above absolute
zero. The sample is loaded into a miniaturized
magnetic trap. Evaporative cooling is used to
cool the atoms further by ejecting the hottest
atoms from the trap, to allow the remainder to
equilibrate at a lower temperature. This
cooling technique is continued until the BEC
state forms, which is then studied by various
means.
Impact:
Atom lasers are expected to be the key to a new
generation of “quantum technologies”, including
sensors which employ atom interferometry of
coherent atoms to achieve unprecedented sensitivity.
Matter-wave holography has potentially significant
advantages over conventional lithography techniques.
The use of BEC to demonstrate an atomic laser
This research is at the forefront of advances in
modern physics. It was selected from the OBPR
00 NRA
Quantum Interferometer Test of Equivalence
Mark Kasevich, Yale University
QuITE will search for limits to Einstein’s relativity
Investigation Selected from 00NRA but does not have funding
Why:
Atom, wave interferometry is an exciting new
development based on laser cooling and
trapping. Development of instruments based on
this approach allows exacting tests of the
fundamental physics, including Einstein’s
Equivalence Principle (EEP). This approach
towards testing the EEP is also distinguished by
the feature that tests masses are comprised
from atoms, which are quantum entities. Thus
matter wave interferometry allows both a high
sensitivity test, and one that can directly probe
the coupling of gravity to mass at quantum
mechanical scales.
How:
Laser cooling techniques will be used to
simultaneously cool and trap both rubidium
and cesium atoms. These atoms are allowed
to free fall in space, while pulses of light
excite Raman transitions to split and
recombine the atom waves, and form the
interferometers. Atom waves propagating in
each arm of the interferometer experience
different phase shift in their free fall, allowing
the determination of the acceleration of
gravity. Comparison of the acceleration
experienced by the two atomic species allows
testing the EEP.
Impact:
Identification of the boundaries of the general
relativity, and all metric gravity, is crucial to
developing models that reconcile gravity with
quantum mechanics. This is arguably the most
outstanding problem in Fundamental Physics, today.
Quantum particle-wave duality
This research is at the forefront of advances in
modern physics. It was selected from the OBPR
00 NRA
Fundamental Physics Baselined Budget as of 01-31-2003
Prior
FY’03 FY’04 FY’05 FY’06 FY’07 FY’08 Total
213.764 36.056 32.290 49.562 41.416 44.191 46.406 463.685
Future
• Had a good run
• Almost made it to ISS
• Partially recoverable…but need
• FP Community vigorous advocacy to acquire
fundings and upmass
– NRC Decadal Report
• Ask what NASA can do for you