SMOV3A REQUIREMENTS
This is a mark-up of the SM3 SMOV Level III Requirements Document
(SMO-1000, App. H, June 26, 1998), that originally addressed a
single SM3 mission.
The entries in purple indicate those
requirements which apply to SMOV3b, only.
SMOV3A.
All else applies to
The entries in blue indicate wording changes or typo-
corrections with respect to the original document.
(Note:
As of
9 April 99, these changes have not yet undergone the CCB review
process.
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H.11 Observatory Verification.
The Servicing Mission Observatory
Verification (SMOV) period starts when the HST is released from
the Orbiter and encompasses those activities required to re-enable
science observing with the HST.
The goal of this program is to
safely and quickly return HST to normal science operations with
specific on-orbit checkout planned only for those subsystems and
instrument packages directly affected by servicing.
Those sub-
systems and capabilities that are not expected to be affected
by the servicing mission will be examined by the SMOV Planning Team
with contingency plans developed for system level or critical path
activities in the event that the assumed capabilities are not
available.
During the SMOV period there will be no planned, unnecessary
exercising of the instruments and subsystems (i.e., activation of
modes not planned for use in normal operations) which specifically
precludes activities such as switching to redundant signal paths or
activation of fail-safe mechanisms to verify that they work.
As
much as possible, engineering requirements will be verified by
monitoring and trend analysis of otherwise motivated activities
occurring over the course of the SMOV period to alleviate the
allocation of spacecraft time to requirements that can be verified
over time with routine telemetry. Science checkout and calibrations
will encompass only those activities required to recommission the
HST Observatory for the cycles 8 & 9 science program with the
remainder of the science calibration and on-orbit verification
occurring in conjunction with cycles 8 & 9 science operations.
This will include verification that the new scientific instrument
meets those Contract End Item (CEI) Specification performance
requirements not previously verified and which are most pertinent
to the science program.
H.11.1
WFPC II Verification Requirements.
The following two
assumptions apply to WFPC II at the point of HST release:
1.
WFPC II is in PROTECT-SAFE mode.
2.
The WFPC II shutter is closed with the F785LP filter in
place.
H.11.1.1
H.11.1.1.1
Engineering Activation and Check-Out Requirements
After release, the instrument shall undergo an
active decontamination procedure of at least 12 hours.
In the
interval between release and the start of the decontamination
procedure, the shutter shall remain closed and the Thermal
Electric Coolers (TECs) shall remain off.
H.11.1.1.2
Upon completion of the decontamination procedure,
the instrument shall undergo a contamination verification phase
of at least 48 hours which shall be monitored by the ST ScI.
Upon the approval of ST ScI, the instrument shall be cooled to
its nominal operating temperature and the AFMs shall be reset.
H.11.1.1.3
Following TEC turn on, a standard UV stellar
monitor shall be scheduled at least twice during the first week
and, starting with the second week, at a declining frequency for
the duration of SMOV as part of the WFPC II Cycle 8/9
calibration program.
[The ST ScI will use the UV monitor to
determine whet-her the instrument remains at its operating
temperature or under-goes further decontamination.]
H.11.1.1.4
A short-wavelength (approximately Lyman alpha)
stellar observation shall be performed.
H.11.1.2
Science Verification Requirements
H.11.1.2.1
The baseline instrumental performance and optical
alignment and focus of the WFPC II shall be measured from an initial
set of PSF measurements, photometric calibrations and internal calibrations (dark frames, bias frames, K-spot images, and internal flat
fields).
Subsequent to this initial set of measurements, all WFPC
II calibrations will be performed as part of the Cycle 8/9 WFPC II
calibration program.
H.11.1.2.2
A second PSF measurement will be performed after the
NCS achieves its normal operational state.
H.11.2
H.11.2.1
COSTAR Verification Requirements
After the successful installation of ACS and after
re-lease, the COSTAR Deployable Optical Bench shall be retracted
from the stow to launch position and then return COSTAR to Hold
mode.
H.11.3
ACS Verification Requirements
H.11.3.1
H.11.3.1.1
Engineering Requirements
ACS entry into each of four instrument states
(Boot, Hold, Operate, Observe) shall be demonstrated.
Operations shall be commanded via RIU commands transmitted over
the Supervisory Bus.
H.11.3.1.2
ACS entry into each of the defined detector states
shall be demonstrated.
Operations shall be commanded via RIU
commands transmitted over the Supervisory Bus.
H.11.3.1.3
ACS command and engineering data interface via the
RIU and science data transmission via the Science Data Formatter
(SDF) shall be verified by monitoring of normal configuration
and science activities.
H.11.3.1.4
The ability to load and dump on-board memory shall
be demonstrated.
H.11.3.1.5
The ability to read and write data from and to the
science data buffer shall be demonstrated.
H.11.3.1.6
The performance of the Cal/Coronagraph Door, M3
Fold Mechanism, IM1 and M1 Alignment and Focus Corrector
Mechanisms, WFC/HRC Filter Wheels 1 and 2, SBC Filter Wheel, and
WFC and HRC CCD shutters shall be verified.
H.11.3.1.7
The functionality of the ACS Calibration Lamps
shall be verified, either by the execution of engineering
test(s) or as a result of detector performance testing.
Operation of the deute-rium lamp shall be deferred for an
initial outgassing period following release of the observatory,
as defined in the CARD.
H.11.3.1.8
Functional tests shall be executed for all three
ACS detectors. Proper accumulation of signal over a specified
time interval and data readout (including compressed data) shall
be demonstrated.
For the CCDs, readout of a single subarray and
commandability of gain setting shall be demonstrated.
H.11.3.1.9
The ability of the TECs to cool and stably control
the CCDs shall be tested at a small number of temperature set
points, in order to determine the coldest stable operating
point, which is the final setting desired.
that this point be at least as cold as -80C.
The requirement is
This test may
dependent on the operation of the ASCS.
H.11.3.1.10
ACS operations shall be managed to minimize risk
of contamination of its optical surfaces by materials outgassed
either internally or from other units installed during the SM as
well as from the payload bay environment during servicing. The
ACS Cal Door shall be used to provide ACS contamination protection during installation and while the OTA is viewing the bright
earth for the duration of the SMOV program. A contamination
moni-toring program shall be initiated as early as possible
after the SM.
H.11.3.1.11
High voltage operation of the ACS SBC MAMA
detector shall be delayed for an initial outgassing period
following re-lease of the observatory, as defined in the CARD.
H.11.3.2
Target Acquisition Requirements
H.11.3.2.1
The location of
a reference ACS HRC camera
aperture shall be determined with respect to the FGS reference
frames to an accuracy of +/-1 arcsecond in V2-V3 coordinates and
10 arc minutes in aperture rotation angle.
H.11.3.2.2
The relative positions of the ACS coronagraphic
field masks determined during ground test shall be confirmed.
H.11.3.2.3
The ability of the FSW to perform isolated point
source acquisition onto the coronagraphic spots shall be demonstrated with the ACS HRC detector. Successful execution of these
acquisitions will also demonstrate the ability of the FSW to
cal-culate the centroid of target positions and to perform
automated telescope pointing.
H.11.3.3
Optical Alignment Requirements
H.11.3.3.1
The encircled energy and image diameter vs. wave-
length shall be measured over a grid of focus and tilt positions
for both IM1 and M1 correctors.
These measurements shall be
used to set the nominal corrector positions.
H.11.3.3.2
The camera mode image quality at the detectors over
the full field shall be measured via broad and narrow band imaging of stars.
The requirement for encircled energy in the WFC
and HRC is 75% within a diameter of .25 arcseconds, through the
F502N filter.
The requirement for encircled energy in the SBC
is 30% within a diameter of
0.10 arcseconds, for a star
observed through the Lyman alpha filter.
H.11.3.3.3
The internal stability of ACS from coronagraphic
field stop to HRC detector shall be monitored.
The image shifts
seen shall be compared to the specified stability of 0.12 HRC
pixels RMS over 1300 s and +/- 0.20 HRC pixels over a three hour
period.
H.11.3.3.4
The pointing and throughput stability of the OTA-
ACS combination shall be measured over several orbits.
The
purpose of these measurements is twofold:
1.
Confirm that the typical thermal environment after SM3
does not cause unacceptable image drifts;
2.
Confirm that operation of the ASCS does not degrade
the ACS image quality or pointing stability.
H.11.3.3.5
The ACS Point Spread Function (PSF) in normal
imaging and coronagraphic modes shall be measured.
H.11.3.4
H.11.3.4.1
Calibration Requirements
The plate scale, orientation and geometric
distortion shall be measured for each of the ACS channels by
imaging an astrometric field.
Relative location of each
aperture in the FGS frame shall also be determined with these
measurements.
H.11.3.4.2
Dark rate and read noise and CTE for each CCD detec-
tor shall be measured, as well as dark rate for the SBC MAMA
detector.
One purpose of these measurements is to confirm that
the operations of the STIS, the ASCS, and the NCS do not affect
the noise properties of the detectors.
The hot pixel creation
rate shall be assessed and the efficacy of the hot annealing
cycle shall be demonstrated.
H.11.3.4.3
Instrument sensitivity vs. wavelength shall be
measured for a subset of ACS modes. Sensitivity measurements
shall be performed using astronomical standard stars.
As part
of this process, UV sensitivity measurements shall be obtained
as early as possible, to enable early trending of UV
sensitivity.
H.11.3.4.4
The instrumental polarization as function of
wavelength shall be measured for both WFC and HRC channels.
H.11.3.4.5
The flat field uniformity per pixel and cosmetic
defect fraction shall be measured for each of the 3 ACS
detectors.
The ability to determine the residual response
variation using the ACS internal calibration sources shall be
demonstrated. The difference between sky flats and internal
flats and temporal stability of the flat field correction shall
be assessed.
H.11.4
NICMOS Verification Requirements
H.11.4.1
H.11.4.1.1
Engineering Activation Requirements
The ability to command NICMOS via the RIU, science
data transmission via the SDF, and the ability of NICMOS to
transition between its primary operational states (HOLD, BOOT,
SAA-OPER, OPERATE, and OBSERVE) shall be verified.
H.11.4.1.2
The integrity of the NICMOS FSW shall be demonstrated.
H.11.4.1.3
Operation of the NICMOS mechanisms (PAM, FOM, and
filter wheels) shall be tested. PAM motion between -9.5 and +4.0
mm of focus travel and +/- 10 steps in X and +/-12 steps in Y
tilt shall be demonstrated. The ability to reposition the field
off-set mirror (FOM) to within 10 milliarcseconds over the full
operational range of travel shall be demonstrated. Internal lamp
exposures shall be obtained at each filter
wheel position.
H.11.4.1.4
The operational temperature of the detectors at
their baseplate shall be maintained to within 1 degree K of the
nominal operational temperature as determined by models of NCS
performance.
Detector temperature stability shall be charac-
terized over periods of 60s, 2000s, 24 hours, and 30 days.
H.11.4.1.5
The thermal stability of the Vapor Cooled Shield
(VCS)shall be determined to be within +/- 5 degrees K of the
nominal operating temperature as determined by models of NCS
performance.
H.11.4.2
H.11.4.2.1
Target Acquisition Requirements
The location of each NICMOS camera aperture shall
be determined with respect to the FGS reference frames to an
accu-racy of +/- 2 arcseconds in V2-V3 coordinates and 7 arc
minutes in aperture rotation angle for Camera 2 and 1 degree for
cameras 1 and 3.
H.11.4.2.2
The performance of the coronagraph shall be demon-
strated by an observation of an isolated point source following
an onboard acquisition (Mode 2 acq) with an autonomous location
of the coronagraphic hole.
H.11.4.3
Optical Requirements
H.11.4.3.1
The optical plate scales at each of the detector
focal planes shall be measured, with a precision of 1/4 of a
Camera 2 pixel(nominally 18.8 mas).
H.11.4.3.2
Optical alignment shall be restored to the level of
performance achieved during Cycle 7. PAM focus setting should be
measured and trended to establish and maintain focus within +/1mm of nominal (best) focus for each Camera. After pupil adjustment, the combined effect of all NICMOS internal optics shall
add a wavefront error, at the FPA, of no greater than lambda/20
(rms) at wavelength of 1.083 microns. The encircled energy
within a 100 mas (200 mas for Camera 3) radius of an unresolved
point-source shall be measured.
H.11.4.3.3
H.11.4.4
H.11.4.4.1
Root mean square image motion shall be characterized.
Calibration Requirements
The ability to determine residual pixel-to-pixel
variation using the internal flat-field calibration source shall
be demonstrated.
The stability of the instrumental flat-fields
will be characterized over timescales of orbits, days, and one
month.
H.11.4.4.2
The ability to calibrate spectral throughput shall
be demonstrated. The goal is the calibration of the absolute
flux level to an accuracy of approximately 10%. Total instrument
throughput shall be determined and compared to that measured
previously during Cycle 7.
H.11.4.4.3
The ability to do differential photometry with a
residual measurement error no greater than 3%, and a temporal
stability of 3% over a month shall be demonstrated. The consequences of detector temperature stability will be assessed.
H.11.4.4.4
NICMOS geometric stability will be characterized as
a function of orbital elements, vehicle orientation, and dewar
temperatures by measuring the lateral motion of the image in the
Camera 2 focal plane.
H.11.4.4.5
Detector read noise and dark current shall be
measured and compared to Cycle 7 values.
mean read noise is <35 electrons.
The expectation for
The goal for mean dark
current is TBD electrons/second.
H.11.4.4.6
The cosmic ray background will be measured and
confirmed to be comparable to the Cycle 7 levels.
H.11.4.4.7
HST and NICMOS thermal emission will be charac-
terized as a function of spectral element and time.
H.11.4.4.8
The decay timescale for image persistence will be
determined for both images from external sources of light and
from cosmic rays.
H.11.4.4.9
The photometric and wavelength solutions for the
G096 and G141 grisms will be remeasured.
H.11.4.4.10
During the initial cooldown phase, NICMOS detector
dark current and flat-field performance in all three cameras
shall be measured in 5-degree steps starting at 100 degrees K.
H.11.4.5
NICMOS Cooling System (NCS) Engineering Verification
Requirements
H.11.4.5.1
Configure the NCS to re-cool NICMOS detectors and
verify NICMOS background noise is reduced to scientifically
useful levels.
The goal during SMOV is to verify the capability
to maintain the NICMOS Cooling Coil temperature less than or
equal to 70 +/- 0.1K.
H.11.4.5.2
Verify the capability of the NCS to achieve and
maintain a NICMOS Cold Well temperature of 72 Kelvin.
H.11.4.5.3
Verify the NCS capability to provide adequate level
of thermal stability and repeatability for NICMOS science
operations.
H.11.4.6
H.11.4.6.1
NICMOS/NCS Calibration and Performance Requirements
The temperatures of each NICMOS detector, along
with its range of variation and the timescales for variation,
shall be determined.
H.11.4.6.2
The temperature of the VCS (and hence the filter
elements), along with its range of variation and the timescales
for variation, shall be determined.
H.11.4.6.3
The absence of spurious signal or noise in the
NICMOS detectors due to NCS operation shall be verified.
H.11.4.6.4
If the NCS transitions into IDLE Mode, the
magnitude and repeatability of changes in NICMOS focus shall be
determined.
H.11.4.6.5
If the NCS transitions into IDLE Mode, the
repeatability and settling timescale for the VCS temperature
shall be determined.
H.11.4.6.6
If the NCS transitions into IDLE Mode, changes in
detector pixel behavior and the positioning and quantity of
detector focal plane contamination ("grot") shall be determined.
H.11.5
STIS Verification Requirements
H.11.5.1
H.11.5.1.1
Engineering Requirements
STIS entry into each of four instrument states
(Boot, Hold, Operate, Observe) shall be demonstrated.
Operations shall be commanded via RIU commands transmitted over
the Supervisory Bus.
H.11.5.1.2
STIS command and engineering data interface via the
RIU and science data transmission via the Science Data Formatter
(SDF) shall be verified by monitoring of normal configuration
and science activities.
H.11.5.1.3
The performance of the Mode Select Mechanism, Slit
Wheel, Calibration Insert Mechanism, Mode Isolation Shutter,
Echelle Blocker, CCD Shutter and Focus Adjust and Corrector
Alignment Mechanism shall be verified, as part of normal
operations.
H.11.5.1.4
Minifunctional tests shall be executed for all
three STIS detectors. The high voltage for the STIS MAMA
detectors will not be activated until the ambient pressure is
below TBD.
H.11.5.1.5
The ability of the TEC to cool and stably control
the CCD shall be tested at a small number of temperature set
points, in order to determine the coldest stable operating
point, which is the final setting desired.
The requirement is
that this point be at least as cold as -80 degrees C.
This test
may be dependent on the operation of the ASCS and the NCS.
H.11.5.1.6
Contamination plan:
1. The STIS shutter shall be used to provide STIS
contamination protection in addition to the contamination management plan defined in H.11.16.
2. The STIS Deuterium and Krypton lamps will not be operated
until TBD weeks after release.
3. STIS sensitivity will be monitored periodically.
H.11.5.2
H.11.5.2.1
Target Acquisition Requirements
The location of a reference STIS camera aperture
shall be determined with respect to the FGS reference frames to
an accuracy of 11 arcsecond in V2-V3 coordinates and 10 arc
minutes in aperture rotation angle.
H.11.5.3
H.11.5.3.1
Optical Alignment Requirements
The slit plane encircled energy vs. wavelength and
image diameter shall be measured for the nominal corrector focus
and tilt positions.
If the throughput is significantly lower
than pre-SM3 measurements, further corrector alignment and
testing will be performed.
The requirements at center of field
are 36% energy within the 0.1x0.09 slit at 145 nm and 48% energy
within the 0.1x0.09 slit at 633 nm.
This test is dependent on
the setting of the HST secondary mirror position, which must be
set to nominal focus prior to the throughput test.
H.11.5.3.2
The nominal values for Slit Wheel positions, based
on slit/aperture choice, and Mode Select Mechanism positions,
based on detector/grating/wavelength (or order) choice, shall be
verified.
Determination of shifts of nominal positions shall
result in modification of the on-board mechanism calibration
tables.
H.11.5.3.3
MSM and Slit wheel positions will be checked at a
few settings at off-nominal cooler temperatures to check operations during planned cooler excursions.
H.11.5.3.4
The slit-to-detector internal stability of STIS
shall be monitored.
The spectral shifts seen shall be compared
to the specified stability of 0.2 low resolution MAMA pixels
over a one hour period. The purpose of this measurement is
twofold:
1.
Confirm that the typical thermal environment after SM3
does change the requirements for frequency of wavelength
calibration for typical astronomical observations.
2.
Confirm that operation of the NCS and ASCS do not
degrade the STIS spectral image quality.
H.11.5.3.5
The pointing and throughput stability of the OTA-
STIS combination shall be measured over several orbits. The
purpose of this measurement is threefold:
1.
Confirm that the typical thermal environment after SM3
does not cause unacceptable image drifts.
2.
Confirm that operation of the NCS and ASCS do not
degrade the STIS image quality or pointing stability.
3.
Confirm that the STIK installation has not induced
forces that are deforming the optical bench.
H.11.5.4
Calibration Requirements
H.11.5.4.1
Dark rate and read noise for each detector shall be
measured at the nominal operating temperatures, and will be
periodically monitored to track variations with time and
temperature. The goals are:
1.
To confirm that operation of ACS, the ASCS, and the NCS
do not affect the noise properties of the detectors.
2.
To calibrate NUVMAMA dark rate vs. temperature and time
from SAA in the post-SM3 operating environment.
H.11.5.4.2
Instrument sensitivity vs. science mode and wave-
length, shall be measured for the low-resolution spectroscopic
modes for contamination monitoring.
Sensitivity measurements
shall be performed using astronomical standard stars.
Sensitivity shall be measured at different values of the MAMA
temperatures.
H.11.5.4.3
NUVMAMA dark current reduction afforded by the ASCS
shall be demonstrated.
H.11.6
Early Release Observations
H.11.6.1
SMOV activities shall include early release
observations with at least the WFPC2 science instrument.
The
resulting science data products shall be released into the
public domain to demonstrate the improved HST capabilities.
H.11.7
Optical Telescope Assembly/Fine Guidance Sensor Verification Requirements
The following is a preliminary list of OTA/FGS verification
requirements for the Third Servicing Mission SMOV. They
these requirements have been based on the referenced documents.
H.11.7.1
H.11.7.1.1
Optical Interfaces
HST's secondary mirror shall only be moved to com-
pensate for desorption in the graphite epoxy structure.
H.11.7.2
FGS S-Curve Restoration Activities (applicable if an
FGS is replaced).
The FGS shall be peaked up by the vendor and
then turned over to operations and science to optimize the
location of the articulated FGS fold flat #3.
H.11.7.2.1
The FGS vendor will be given an opportunity to peak
up the S-Curves in the central and off-axis locations.
Both the
Central Position Modulation Index (CPMI)and the Off-Axis Modulation Index (OAMI) shall be determined in this operation for a
fold flat #3 position which maximizes both values.
The deter-
mination of these values may be done using a mixture of both
analysis and on-orbit test data.
The precise star used for
evaluating performance shall be determined by the agreement
between the vendor and the HST operations.
At any time, the
government may elect to use the analysis in the incentive fee
evaluation and may require no further fold flat #3 moves.
H.11.7.2.2
The pupil centering with respect to the face of the
Koester's prism shall be accomplished by articulating FGS fold
flat #3 (FF3). The modulation of the X and Y S-curves shall be
optimized at a particular field location that is chosen to produce an acceptable set of S-curves over the entire FGS FOV.
Performance at the selected field location shall be deemed adequate if the S-curve modulation in each axis is within 10% of
the maximum value achieved during the final laboratory
optimization procedures. The wavelength characteristics of the S
Curve at the relevant central location in the FOV will be
baselined using F583W, PUPIL, and the red filter.
H.11.7.2.3
A test to determine whether the optimal orientation
of FF3 is affected by desorption shall be performed two to six
months after the baseline alignment of FF3 is completed.
It
will consist of obtaining an S-curve near the FGS FOV location
used for the baseline alignment.
H.11.7.2.4
After the orientation of FF3 has been optimized the
position of the Internal Test Source (ITS) shall be measured.
This result together with a prediction of the Optical Control
Subsystem (OCS) obscuration zone shall be used to update PDB
cone 5, which describes the FOV avoidance zone about the OCS
center where guide stars can neither be acquired nor moved.
H.11.7.3
H.11.7.3.1
FGS Calibration
Mini-OFAD/Plate Scale calibrations for operational
use shall be executed in all three FGSs.
Onboard flight
software table updates and PDB updates incorporating the new
calibrations shall be made.
H.11.7.3.2
FGS-to-FGS alignment calibration shall be performed
and resulting alignment matrices computed.
Onboard tables and
the PDB shall be updated with the new calibration parameters.
H.11.7.3.3
A check on the stability of the Mini-OFAD and FGS-
to-FGS Alignment parameters, and on the stability
of the S-
curve restoration, shall be made two to six months after the
calibra-tions.
ITS measurements shall be obtained to verify
positional stability of the FF3. These data will be used to
verify and change (if necessary) the operational K parameters
for the new FGS.
H.11.7.3.4
A PMT calibration for a replacement FGS shall be
derived from brightness measurements of stars acquired while
conducting other FGS and non-FGS SMOV activities.
H.11.7.3.5
If an FGS is replaced, dark count data will have
been obtained in all FGSs during the replacement FGS functional
checkout.
If no FGS is replaced, dark counts shall be acquired
on a target of opportunity basis.
H.11.7.3.6
The operational performance of the replacement FGS
will be verified in an operational environment. Standard guide
star acquisition and tracking of bright and faint guide stars
will be exercised.
The jitter and noise characteristics during
slews and fine lock pointing will be compared to nominal
tolerances.
H.11.7.3.7
FGS pointing stability will be verified to be com-
patible with ASCS/NCS operation.
H.11.7.4
H.11.7.4.1
FGS Astrometry Science Re-Commissioning
The decision to re-enable the astrometry FGS for
science will be partly based on the repeatability and stability
of the S Curve. Performance shall be deemed adequate if the S
Curve exhibits small amplitude and morphology changes that are
consistent with the temporal variations seen in
time.
S Curves over
These data will be also be used to assess the operational
performance of the FGS1R across the FOV and to determine if
contingency FGS1R FF3 re-optimization is necessary to preserve
operational integrity.
H.11.7.4.2
The re-enabling of astrometry science will also
depend on the repeatability of the optical field angle
distortion calibration.
An LTSTAB orbit will be obtained and
compared to the pre-servicing mission standards. If the LTSTAB
adjustments can remove all differences introduced by servicing
mission activities,
the integrity of the astrometer is
established.
H.11.7.4.3
Serendipitous photometric observations from the
LTSTAB verification orbit will be used to verify the photometric
stability of the astrometry FGS.
H.11.8
Pointing Control Subsystem Verification Requirements
H.11.8.1
The initial attitude shall be determined to an
accuracy within .2 degrees using Fixed Head Star Tracker (FHST)
data.
H.11.8.2
The gyro drift rate bias shall be calibrated to
within 0.05 arcseconds per second prior to the first guide star
acquisi-tion.
H.11.8.3
The FHST/FHST alignment matrices shall be computed,
using FHST observations at the initial attitude, to an accuracy
of 5 arcseconds (1s).
The FHST/FHST alignment matrices shall be
updated if the change in the pitch or yaw alignment exceeds 20
arcseconds.
The alignment computations will be further refined
during normal operations to achieve accuracy comparable to the
pre-Servicing Mission level.
H.11.8.4
If gyros are changed out, the gyro to FHST alignment
matrices shall be updated to an accuracy that reduces the attitude error following a vehicle maneuver to less than one arcsecond per degree of slew.
H.11.8.5
The PCS shall acquire guide stars in fine lock.
H.11.8.6
The vehicle jitter during periods of fine lock shall
be measured.
H.11.8.7
Perform a post SM3 HST Modal Test to properly charac-
terize the on-orbit system modes and jitter.
H.11.9 HST 486 Verification Requirements
H.11.9.1
HST486 Thermisters shall be configured for
appropriate temperature monitoring.
H.11.9.2
DMS (SSM486 flight software) shall be configured to
provide nominal operation of the safemode tests and software
safemodes.
H.11.9.3
After transition to normal mode, HST 486 performance
shall be verified by observing the following:
1.
Vehicle slews
2.
Science maneuvers
3.
Solar Array slews
4.
HGA slews and TDRSS track
5.
FGS acquisitions
6.
FGS diagnostics
7.
Events Status Buffer management
8.
Telemetry and recorder management
9.
SPC processing
10. BMIC management
11. FGS observer performance
12. VT and/or KR software charge control
13. SPAR performance
14. Gyro bias estimation/extrapolation performance
H.11.9.4
The SSM flight software shall maintain the position
vectors for up to four TDRSS spacecraft, and calculate the
following position and velocity vectors from a flight tested
analytical model at a 1 Hz rate.
1.
Solar
2.
Lunar
3.
Magnetic field
H.11.10
Instrumentation & Communications Subsystem
Verification
Requirements
No applicable requirements.
H.11.11
H.11.11.1
SI C&DH Verification Requirements
Verify that the NSSC-I interface with the HST486
shall support spacecraft operations and commanding of the post
SM-3 complement of SIs.
H.11.11.2
A NSSC-1 load supporting the post SM3 SI configura-
tion shall be loaded during SMOV.
The NSSC-1 load will be
required to remove FOC memory for additional command storage.
Load and verification activities shall include pre- and postinstallation dump of the NSSC-1 and regression testing of NSSC-1
functionality.
H.11.12
Structures and Mechanisms Subsystem Verification
No applicable requirements.
H.11.13
Thermal Control Subsystem Verification Requirements
H.11.13.1
All active thermally controlled SSM systems status
shall be verified by analysis of neighboring telemetry parameters
[i.e., SSM ES Bay 1: Computer baseplate heater, Bays 2 & 3:
Battery heaters, Bay 4: Door heaters, Bay 5: Comm tray & Recorders
(2) heaters, Bays 6 & 9: RWA heaters, Bays 7 & 8: Door heaters,
ESTR-2 heater, Bay 10: SI C&DH Tray heaters, AS shelf: RSU(3) and
FHST(3) heaters, External: CSS(5), AD drive/latch heaters, Latch/
Drive heaters, MSS heaters, Retr/Depl heaters, and SADM heaters].
H.11.14
Aft Shroud Cooling System (ASCS) Engineering
Verification Requirements
H.11.14.1
Verify the heat rejection capability of the ASCS to
maintain ACS and STIS subsystems at temperatures supporting
achievement of each instrument’s science performance for Cycles
8 and 9 operations.
The goal during SMOV is to verify the
capabi-lity to maintain the following interface plate
temperatures:
1.
Less than or equal -2 degrees C for ACS
2.
Less than or equal 4 degrees C for STIS
3.
Less than or equal -5 degrees C for STIS (dark)
4.
Greater than or equal 25 degrees C for STIS (boil)
H.11.14.2
Verify the ASCS capability to provide adequate level
of thermal stability and repeatability for ACS and STIS science
operations.
H.11.15
Solar Array III (SAIII) Verification Requirements
H.11.15.1
SAIII drive system performance shall be
characterized during the SMOV period and the following
requirements verified.
1.
the sensed position is within +/- 3.5 degrees of the
commanded position when operating within the range 0 to
130 degrees,
2.
the sensed position is within +/- 5.0 degrees of the
commanded position when operating within the remainder of
the range,
3.
the maximum command profile error shall be less than the
safemode test threshold.
H.11.15.2
SAIII power generation performance shall be assessed
and compared to Beginning of Life (BOL) predictions that account
for expected degradation.
To the extent possible, measurements
shall be recorded when HST is at orbit noon, when the Sun vector
is within +/-10 deg of the -V1 axis, when the SA/Sun incidence
angle is less than 5 deg, and when all the CCC K-relays are
closed.
H.11.16
General Verification Requirements
H.11.16.1
The HST optics shall be protected from contaminants
being polymerized by the solar UV light reflected by the earth
in the early stage of outgassing following SM3.
The following
con-tamination management plan shall be carried out to provide
the protection described below.
1.
Avoid pointing the +V1 axis within 15 degrees of bright
earth limb from the time HST is released by the Orbiter
through release +3 days.
2.
Avoid pointing the +V1 axis within two degrees of the
bright earth Limb from release +3 days through release
+12 days.
3.
From release +12 days through release +42 days the cumulative exposure of the focal plane to the earth (+V1 axis
within two degrees of the bright-earth surface) is not to
exceed the total bright earth exposure (approximately six
days) experienced by HST during the first six weeks following the Second Servicing Mission.
H.11.16.2
Parallel operation of NICMOS, STIS, and WFPC2, and
ACS shall be demonstrated, with an allowance, if necessary, of
several weeks of response time between the first parallel test
and subsequent operations requiring parallel capabilities.
H.11.17
H.11.17.1
Electrical Power Subsystem Verification Requirements
With the Voltage Improvement Kit (VIK) installed,
the battery charge control performance shall be characterized by
recording a statistically significant data set of individual
battery charge-on and charge-off cutoff voltages.
This data
shall be recorded over the nominal temperature range following
SM3.
The average charge-on and charge-off voltages shall be
compared to the expected values based on VIK specifications and
past performance of the CCC(s).
H.11.17.2
With the K10 bypass relay closed, the SPA Recovery
(SPAR)modifications (relays in the SA3 D-Boxes and associated
flight software)shall control charging of Battery 1 and maintain
thermal stability when operating in conjunction with both
hardware and software charge control modes.
H.11.17.3
A software charge control mode, either Voltage/
Temperature SoftWare Charge Control (VTSWCC) or K-Relay SoftWare
Charge Control (KRSWCC) shall perform charge control and
maintain battery thermal stability while operating in
conjunction with the SPAR modifications.
This shall be verified
for periods of high suntime, low solar array incidence angles,
and at a minimum HST load power for the expected load range
following SM3.
H.11.17.4
A minimum of three batteries shall be capacity
tested at one-month intervals following SM3.