Page 1 PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID 3131c Report Date: 09-May-96:18:03 Version: ********** Check-in Date: ********** 1.Proposal Title: SA FEATHERING TEST ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Proposal Type 5. Continuation ID ENG Sub Category ------------------------------------------------------------------------------------ 6. Principal Investigator Institution Country Telephone J Decker CODE 440 USA ------------------------------------------------------------------------------------ 7. Abstract Thermal gradients on the SA bi-stems have been analytically implicated as the primary source of vehicle disturbances during every HST orbit at night-day and day- night transition. This test will reconfigure the SAs to a series of off-nominal configurations and observe/record the resulting vehicle disturbances at the critical times. The data will confirm or refute the postulated disturbance sources within the SA assemblies, and will reveal the unique disturbance contributions of the +/- V2 SA's. This test data will characterize any changes required in the design of the replacement SA's. ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ 9. Est obs time (hours) pri: 0 par: 0 10. Num targs pri: 1 par: 0 ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ Page 2 I. GENERAL FORM Proposal 3131c PI: J Decker Proposal Title: SA FEATHERING TEST ------------------------------------------------------------------------------------ 1. Proposers: Proposers Institution Country ESA ------------------------------------------------------------------------------------ J. Decker GFSC USA X ------------------------------------------------------------------------------------ 2. Scientific Justification. This test will provide data concerning the behavior of the vehicle during critical times of the orbit of the arrays in off-nominal configurations that will confirm or refute the postulated disturbances sources within the SA assemblies, and will reveal the unique disturbance contrib- utions of the +V2 and -V2 SA's. This info. cannot be obtained by any means other than an on-orbit test involving off-nominal SA config's. The data will be used to determine any modifications to the design of the replacement SAs which are required to minimize the SA induced disturbances. Page 3 ------------------------------------------------------------------------------------ 3. Description of proposed observations. This test will be conducted with the HST in Normal Mode using gyros for attitude reference. The +V1 will be pointed toward the sun. The battery Rate of Charge (ROC) safemode test must be disabled during the entire test; the SA normal Sun Angle Safemode test will be disabled during specific parts of the test by real time commands and then enabled during the test. The disabled tests, with the exception of the battery ROC will be re-enabled at the start of Test Seq. 7 as listed below. The ROC test cannot be enabled until at least 4 more orbits. All critical data e.g format PN data, will be downlinked in realtime when possible, and recorded on the ETR as a backup, and will be dumped to the STOCC to ensure that all critical data are available for either real time or near-real time analysis. The nominal orientation of th SAs for this test is an angle of +90 degs. This test consists of series of SA positioning slews that a) place the the -v2 wing 'edge-on' to the sun; b) place the +v2 wing 'edge-on' to the sun; c) simulta- neously place the wings at an agle of 6 degs off nominal; d) place both wings 'edge-on' to the sun. At least one 15-min forward link contact is required during the time that one or both wings are in the 'edge-on' configuration to enable the wings to be commanded back to the nominal orientation in the event that the any problems are en- countered; these are designated as critical forward link service. The foregoing test configurations will be maintained thruout one night/day, orbit day, day/night transition cycle; the wings will be slewed back to the nominal orient. after the tests at all configurations EXCEPT c). The wings will be slewed back to the test configurations using realtime commands and will be slewed back to the nominal orientation using stored commands. Test configs a), b), c) and d) must be established no later than 15 mins prior to a nite/day transition. 2 opportunities for sending the commands to establish the configuration with the +v2 wing 'edge-on' to the sun, and 2 for sending the commands to establish the config's. for both wings 'edge-on' to the sun, are provided to ensure that the config's can be established prior to a nite/day transition in the event that the first opportunity is missed. The wings should be slewed back to nominal orient. no sooner than 15mins after teh day/nite transition for configurations a), b), and d). A recovery period is required after the test at each configuration to permit the battery SOC toreturn to the level that prevailed at the start of the test at that particular config. The slew of both winds to an orient. of 6 degs off nominal should be scheduled to occur after the 2nd recovery orbit following the test of the +v2 wing in 'edge-on' orient. The slew to 6-degs must be timed such that its mid-point coincides with a nite/day transition The slew will be executed with the SA brake off to determine any changes in vehicle response. The config's. at 6 deg's will be maintained thruout the next orbit day and day/nite transition; both wings will then be slewed to the 'edge-on' config. w/o first being slewed back to the nominal orientation. The sequence of test config's, the # of orbits for each configuration, are given below: TEST ARRAY POSITION # ORBITS/SEQUENCE SEQ. +v2 -v2 1 90 0 2 2 90 90 3 3 0 90 1 4 90 90 2 5 84 84 1 6 0 0 1 7 90 90 2+ During the test sequence, the thermal data and potentiometer data contained in telemetry format AN, and the PCS data contained in telemetry format PN to be used to further characterize the SA-induced attitude distur- bance problem will be collected according to the following schedule. All the data collected are to be recorded at all times; however data straddling the nite/day and day/nite transitions are desired in realtime to the max. extent possible. TEST SEQ ORBITS FORMAT 1 1 AN 2 PN 2 1,3 AN 2 PN 3 1 PN 4 1 AN 2 PN 5 1 PN 6 1 PN 7 1,2 AN Page 4 ------------------------------------------------------------------------------------ 4. Justification of need for HST observations. HST gryo assembly data will be analyzed in time and freq. domains using PSD's. These results will be correlated to the SA config's wrt the vehicle,and and to the vehicle config. wrt to the sun. The data will be compared to the predicted behavior of each array individually, and both together. ESA, GFSC and lmsc-w will participate in the analysis of the results. LMSC-W will process the data and issue a report. ------------------------------------------------------------------------------------ 11. Address Information Name: J. DECKER Category: PI Institution: GFSC Address: City: State: Zip Code: Country: Telephone: Telex (or e-mail): ------------------------------------------------------------------------------------ TARGET LIST a) Fixed Targets ID = 3131c [ 5] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial |Acqui|FLX| Flux data No | Name | Description | Position |Eqnx | Vel. |Prblm|REF| | | | | | | | | ------------------------------------------------------------------------------------------------------------------------------------ 1 SEP S.ECLIPTIC POLE RA = 89.4642D +/- .01", 1990 DEC = -64.48596D +/- .01" ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 3131c [ 6] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |10 | 11 | 12 |13 |14| 15 ------------------------------------------------------------------------------------------------------------------------------------ Line | Seq | Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | S/N |Flx|Pr| Special Number | Name | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| |Rel. Time|Ref| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 SEP S/C POINTIN V1 CONTROL=GYRO 1 1S 1 1 SEQ 1- 33 NO GAP G CYCLE 0 / 1-33 Comments: SLEW TO TARGET SEP VIA STORED COMMANDS ------------------------------------------------------------------------------------------------------------------------------------ 2 SEP S/C DATA V1 CONTROL=GYRO 1 20M 1 1 AFTER 1 BY 10M+/- 5M RT ANALYSIS REQ UPLINK Comments: UPLINK LAUNCH VAL'S OF PCS ACQ. GAINS. NEXT PATCH DF- 224 SFFCHG TO 450 AMP-HRS AND ONN RLM TO 15DEGS. DISABLE SA SUN ANGLE AND BATTERY ROC TEST ------------------------------------------------------------------------------------------------------------------------------------ 3 SEP S/C DATA V1 CONTROL=GYRO 1 20M 1 1 RT ANALYSIS REQ UPLINK Comments: COMMAND -V2 WING TO 0DEG VIA PSTOL SASLEW(0,0). GET -V2/0 CONFIG NO LATER THAN 10M PRIOR TO NITE/DAY X'ING. +V3 AXIS TO SUN AND START 10M+/-5M AFTER NOON ------------------------------------------------------------------------------------------------------------------------------------ 4 SEP S/C DATA V1 CONTROL=GYRO 1 15M 1 1 AFTER 3 BY 15M+/- 5M RT ANALYSIS REQ UPLINK Comments: BACKUP COMMAND FOR -V2 WING TO 0 DEG VIA PSTOL SASLEW. GET -V2 /0 CONFIG NO LATER THAN 10M PRIOR TO NITE/DAY X'ING. IFF 3 FAILS, START 4 @10+/-5M PRE- ORBIT NITE ------------------------------------------------------------------------------------------------------------------------------------ 5 SEP S/C DATA V1 CONTROL=GYRO 1 96M 1 1 CRIT OBS FORMAT=AN AFTER 4 BY 30M+/- 5M Comments: COLLECT/REC FORMAT 'AN' DATA FROM LINE 5 TO 7. ------------------------------------------------------------------------------------------------------------------------------------ 6 SEP S/C DATA V1 CONTROL=GYRO 1 15M 1 1 AFTER 5 BY 45M+/- FORMAT=AN 5M RT ANALYSIS REQ UPLINK Comments: CONTACT REQ'D FOR CONTINGENCY. ------------------------------------------------------------------------------------------------------------------------------------ 7 SEP S/C DATA V1 CONTROL=GYRO 1 51M 1 1 CRIT OBS FORMAT=AN ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 3131c [ 7] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |10 | 11 | 12 |13 |14| 15 ------------------------------------------------------------------------------------------------------------------------------------ Line | Seq | Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | S/N |Flx|Pr| Special Number | Name | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| |Rel. Time|Ref| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 8 SEP S/C DATA V1 CONTROL=GYRO 1 30M 1 1 CRIT OBS FORMAT=PN Comments: COLLECT/REC FORMAT 'PN' DATA FROM LINE 7 TO 9. ------------------------------------------------------------------------------------------------------------------------------------ 9 SEP S/C DATA V1 CONTROL=GYRO 1 15M 1 1 AFTER 8 BY 45M+/- FORMAT=PN 5M RT ANALYSIS REQ UPLINK Comments: CONTACT REQ'D FOR CONTINGENCY. ------------------------------------------------------------------------------------------------------------------------------------ 10 SEP S/C DATA V1 CONTROL=GYRO 1 51M 1 1 CRIT OBS FORMAT=AN Comments: COLLECT/RECORD DATA IN AN FORMAT ------------------------------------------------------------------------------------------------------------------------------------ 11 SEP S/C DATA V1 CONTROL=GYRO 1 96M 1 1 CRIT OBS FORMAT=AN Comments: SLEW BOTH WINGS VIA STORED COMMANDS TO 90DEGS. ------------------------------------------------------------------------------------------------------------------------------------ 12 SEP S/C DATA V1 CONTROL=GYRO 1 15M 1 1 RT ANALYSIS REQ UPLINK Comments: COMMAND TO DUMP ETR ------------------------------------------------------------------------------------------------------------------------------------ 13 SEP S/C DATA V1 CONTROL=GYRO 1 81M 1 1 CRIT OBS FORMAT=AN ------------------------------------------------------------------------------------------------------------------------------------ 14 SEP S/C DATA V1 CONTROL=GYRO 1 96M 1 1 CRIT OBS FORMAT=PN Comments: COLLECT/REC DATA IN 'PN' FORMAT. ------------------------------------------------------------------------------------------------------------------------------------ 15 SEP S/C DATA V1 CONTROL=GYRO 1 48M 1 1 CRIT OBS FORMAT=AN Comments: COLLECT/REC DATA IN 'AN' FORMAT. ------------------------------------------------------------------------------------------------------------------------------------ 16 SEP S/C DATA V1 CONTROL=GYRO 1 20M 1 1 RT ANALYSIS REQ UPLINK Comments: DISABLE SUN ANG.TEST, DUMP ETR, SLEW +V2 WING TO 0DEG VIA PSTOL SASLEW(0,0). GET +V2/0 CONFIG NO LATER THAN 10M PRIOR TO NITE /DAY X'ING. START 10M AFTER NOON ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 3131c [ 8] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |10 | 11 | 12 |13 |14| 15 ------------------------------------------------------------------------------------------------------------------------------------ Line | Seq | Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | S/N |Flx|Pr| Special Number | Name | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| |Rel. Time|Ref| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 17 SEP S/C DATA V1 CONTROL=GYRO 1 20M 1 1 AFTER 16 BY 13M+/- 5M RT ANALYSIS REQ UPLINK Comments: BACKUP COMMAND FOR +V2 SLEW TO 0 DEGS VIA PSTOL. GET +V2/0 CONFIG NO LATER THAN 10M PRIOR TO NITE/DAY X'ING .IFF 16 FAILS , DO 17 @10MIN BEFORE ENTER'NG ORBIT NITE ------------------------------------------------------------------------------------------------------------------------------------ 18 SEP S/C DATA V1 CONTROL=GYRO 1 25M 1 1 CRIT OBS FORMAT=PN Comments: COLLECT/REC DATA IN 'PN' FORMAT , FROM 18 TO 20 ------------------------------------------------------------------------------------------------------------------------------------ 19 SEP S/C DATA V1 CONTROL=GYRO 1 15M 1 1 RT ANALYSIS FORMAT=PN REQ UPLINK Comments: CONTACT REQ'D FOR CONTINGENCY. ------------------------------------------------------------------------------------------------------------------------------------ 20 SEP S/C DATA V1 CONTROL=GYRO 1 192M 1 1 CRIT OBS FORMAT=PN ------------------------------------------------------------------------------------------------------------------------------------ 21 SEP S/C DATA V1 CONTROL=GYRO 1 192M 1 1 CRIT OBS FORMAT=AN Comments: SLEW BOTH WINGS TO 90DEGS AND ENABLE SUN ANG.TEST VIA STORED COMMANDS. GET DATA IN 'AN' FORMAT ------------------------------------------------------------------------------------------------------------------------------------ 22 SEP S/C DATA V1 CONTROL=GYRO 1 15M 1 1 RT ANALYSIS REQ UPLINK Comments: DUMP ETR @1024KBPS ------------------------------------------------------------------------------------------------------------------------------------ 23 SEP S/C DATA V1 CONTROL=GYRO 1 25M 1 1 CRIT OBS FORMAT=PN Comments: COLLECT/RECORD DATA IN 'PN' FORMAT, 1ST COMMAND TO SLEW WINGS TO +84DEGS VIA STORED COMMANDS, 10-12 MINS BEFORE NIGHT/ DAY CROSSING ------------------------------------------------------------------------------------------------------------------------------------ 25 SEP S/C DATA V1 CONTROL=GYRO 1 75M 1 1 CRIT OBS FORMAT=AN Comments: COLLECT/RECORD DATA IN 'AN' FORMAT ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 3131c [ 9] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |10 | 11 | 12 |13 |14| 15 ------------------------------------------------------------------------------------------------------------------------------------ Line | Seq | Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | S/N |Flx|Pr| Special Number | Name | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| |Rel. Time|Ref| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 26 SEP S/C DATA V1 CONTROL=GYRO 1 15M 1 1 RT ANALYSIS REQ UPLINK Comments: DISABLE SA/SUN ANG TEST. SLEW WINGS TO 0 DEGS VIA PSTOL SASLEW PN(0.0,0.0) SET +/- V2 CONFIG. 10M PRIOR TO DAY/NITE X'ING. START @10+/-5M AFTER NOON. ------------------------------------------------------------------------------------------------------------------------------------ 27 SEP S/C DATA V1 CONTROL=GYRO 1 15M 1 1 RT ANALYSIS REQ UPLINK Comments: BACKUP TRY TO DISABLE SA/ SUN ANG TEST & SLEW WINGS TO 0 DEGS. SET +/-V2 CON- FIG.10M PRE-DAY/NITE X' ING. IFF 26 FAILS, START 27 AT 10+/-5M BEFORE NOON ------------------------------------------------------------------------------------------------------------------------------------ 28 SEP S/C DATA V1 CONTROL=GYRO 1 96M 1 1 CRIT OBS FORMAT=PN Comments: COLLECT DATA IN 'PN' FORMAT ------------------------------------------------------------------------------------------------------------------------------------ 29 SEP S/C DATA V1 CONTROL=GYRO 1 15M 1 1 RT ANALYSIS REQ UPLINK Comments: CONTACT REQ'D FOR CONTINGENCY ------------------------------------------------------------------------------------------------------------------------------------ 30 SEP S/C DATA V1 CONTROL=GYRO 1 192M 1 1 CRIT OBS FORMAT=AN Comments: SLEW WINGS TO 90 DEGS VIA STORED COMMANDS. SWITCH TO 'AN' FORMAT FOR 192 MINS. ------------------------------------------------------------------------------------------------------------------------------------ 31 SEP S/C DATA V1 CONTROL=GYRO 1 20M 1 1 AFTER 30 BY 20M +/ - 10M RT ANALYSIS REQ UPLINK Comments: COMMAND TO PATCH ON- NRLIM TO 90DEGS, AND BATTERY ROC SM TEST , & REINSTATE NORMAL PCS ACQ GAINS. ------------------------------------------------------------------------------------------------------------------------------------ 31.5 SEP S/C POINTIN V1 CONTROL=GYRO 1 1S 1 1 AFTER 30 BY 20M+/- G 10M Comments: ENABLE SA/SUN ANGLE TEST VIA STORED COMMANDS. ------------------------------------------------------------------------------------------------------------------------------------ 32 SEP S/C DATA V1 CONTROL=GYRO 1 20M 1 1 AFTER 31 BY 25M+/- 10M RT ANALYSIS REQ UPLINK Comments: COMMAND TO DUMP ETR AT 1024KBPS ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 3131c [ 10] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |10 | 11 | 12 |13 |14| 15 ------------------------------------------------------------------------------------------------------------------------------------ Line | Seq | Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | S/N |Flx|Pr| Special Number | Name | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| |Rel. Time|Ref| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 33 SEP S/C DATA V1 CONTROL=GYRO 1 10M 1 1 AFTER 32 BY 150M+/ -20M RT ANALYSIS REQ UPLINK Comments: COMMAND TO PATCH SFFCHG TO 408 AMP-HRS ------------------------------------------------------------------------------------------------------------------------------------ Summary Form for Proposal 3131c [ 11] Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations S/C ------------------------------------------------------------------------------------------------------------------------------------ Opmodes POINTING DATA ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CONTROL=GYRO FORMAT=AN FORMAT=PN ------------------------------------------------------------------------------------------------------------------------------------ Proposal for ENG ------------------------------------------------------------------------------------------------------------------------------------ S/C Hours ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category ------------------------------------------------------------------------------------------------------------------------------------ Scientific Sub-category ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements SEQ 1- 33 NO GAP; CYCLE 0 / 1-33; AFTER 1 BY 10M+/-5M; RT ANALYSIS; REQ UPLINK; AFTER 3 BY 15M+/-5M; CRIT OBS; AFTER 4 BY 30M+/-5M; AFTER 5 BY 45M+/-5M; AFTER 8 BY 45M+/-5M; AFTER 16 BY 13M+/-5M; CRIT OBS AFTER 30 BY 20M +/- 10M; AFTER 30 BY 20M+/-10M; AFTER 31 BY 25M+/-10M; AFTER 32 BY 150M+/-20M; ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements ------------------------------------------------------------------------------------------------------------------------------------ Target Names SEP ------------------------------------------------------------------------------------------------------------------------------------