Page 1 PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID 2168c Report Date: 09-May-96:16:55 Version: ********** Check-in Date: ********** 1.Proposal Title: G-HRS CARROUSEL PEFORMANCE ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Proposal Type 5. Continuation ID SV/HRS Sub Category ------------------------------------------------------------------------------------ 6. Principal Investigator Institution Country Telephone Dennis C. Ebbets BALL AEROSPACE SYSTEMS GROUP USA 303-939-5964 ------------------------------------------------------------------------------------ 7. Abstract This is an internal test using only the spectral calibration lamp lamp as a target. There are four parts, designed to measure: 1. Mechanical settling time after FPSPLIT type rotations. 2. FPSPLIT overhead times with 2 different flight s/w algorithms. 3. WSCAN overhead times with 2 different flight s/w algorithms. 4. Spectral image stability over 45 minutes. These test provide valuable information about the performance of the carrousel in the HST orbital environment, and timing of the carrousel control s/w in the flight operational system. The results will be used to select an appropriate delay time for the stability check algorithm, and for estimating instrument overhead times for subsequent SV and GTO observations. Updated 8/24/89 to include the parallel S/C mode data within SEQ definitions (PStanley) ------------------------------------------------------------------------------------ 8. Scientific Key Words: GHRS,CALIBRATION,CARROUSEL,FLIGHT SOFTWARE ------------------------------------------------------------------------------------ 9. Est obs time (hours) pri: 0 par: 6.40 10. Num targs pri: 0 par: 0 ------------------------------------------------------------------------------------ 11. Instruments requested: HRS ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ Page 2 I. GENERAL FORM Proposal 2168c PI: Dennis C. Ebbets Proposal Title: G-HRS CARROUSEL PEFORMANCE ------------------------------------------------------------------------------------ 1. Proposers: Proposers Institution Country ESA ------------------------------------------------------------------------------------ D. J. Lindler ADVANCED COMPUTER CONCEPTS USA H. W. Garner BALL AEROSPACE SYSTEMS GROUP USA Dennis C. Ebbets BALL AEROSPACE SYSTEMS GROUP USA ------------------------------------------------------------------------------------ 2. Scientific Justification. The test obtains data to evaluate the performance of the grating carrousel in the zero gravity orbital environment, and the timing characteristics of the flight software carrousel control algorithms. There are five important characteristics measured in four test segments. Each segment is defined for Side 2 (EL lines 1-14) and Side 1 (EL lines 15-28). 1. Settling times: After a very small carrousel rotation, such as will be used for FPSPLIT subexposures, how many seconds must elapse before the motion has ceased and the image is steady? This is purely the mechanical settling time, independent of s/w overhead. 2. FPSPLIT timing: During a series of FPSPLIT subexposures, what is the actual overhead time of the software operations? We will examine two cases, referred to here as the "full stability check" and the "short cut algorithm". This test also provides data useful for evaluating the carrousel repeatibility, which will influence the frequency with which wavelength calibrations must be made. 3. WSCAN timing: Since the G-HRS records only a short segment of the spectrum in a single observation, a sequence of exposures at different carrousel positions will often be required. This test uses a representative scan to empirically measure the overhead time associated with carrousel motions. Again both the full stability check and the shortcut algorithm will be used. 4. Image stability: If an observation of a faint source requires 30 minutes or longer, is it safe to make one long exposure, or should a series of shorter exposures be made? Will the image drift enough in 30 minutes to degrade the resolution? This is a system level test in whicgh effects due to carrousel motion, detector instability and thermal drifts will all influence the new stability of the spectral image. Page 3 ------------------------------------------------------------------------------------ 3. Description of proposed observations. 1. Settling time: The carrousel and Y deflection are set to place a bright emission line near one end of the diode array. A RAPID readout observation is started with 200 msec sample time. Once every 15 seconds the carrousel is moved, via a hardware command, by 4 encoder steps. This will move the image by about 20 diodes. This is repeated 16 times. About 1200 readouts are produced in 4 minutes of integrating. The test is run twice, with the carrousel position incremented in both directions. 2. FPSPLIT timing: At each of 3 wavelengths an observation is made with 4 FPSPLIT subexposurtes. The sequence is repeated 4 times, not necessarily back to back. The test is run once with the "full stability check" and again with the "shortcut algorithm". Each carrousel position is visited 8 times, allowing repeatability to be measured as well. The study of repeatability involves both mechanical and thermal considerations. We have requested S/C parallel data observations to acquire engineering telemetry data. This will allow temperature data to be obtained while the tests are performed. 3. WSCAN timing: The SC2 lamp spectrum is scanned between 1200- 1900 A in steps of 20 A with G160M (36 exposures at lambda = 1200, 1220,1240....1880, 1900), and from 1150 - 1600 A in steps of 15 A with G140M (31 exposures a lambda = 1150, 1165, 1180...1585, 1600). Both carrousel algorithms are used. 4. Image stability: An observation of a bright isolated emission lines is made, consisitng of a new SPYBAL offset, and quarter stepped sampling in X. The observation is repeated 50 times to measure the image location in both X and Y. If repeated without interruptions the series would require about 45 minutes. ------------------------------------------------------------------------------------ 4. Justification of need for HST observations. Similar tests have been performed during the ground based development, and as part of the A&V activities. The mechanical performance is likely to be slightly different in zero G. The ground tests have not duplicated G-HRS software operations in the flight environment, including such issues as the mechanism motion flag and the spacecraft stable flag. Page 4 ------------------------------------------------------------------------------------ 5. Description of special scheduling requirements. SV Prerequisites: i9.1 G140M spectral lamp mini-functional (Prop ID 2767) i9.2 G160M " (Prop ID 2767) i9.4 G270M " (Prop ID 2767) i9.6 Ech-A " (Prop ID 2766) i9.7 Ech_B " (Prop ID 2766) This carrousel test should be run after the OLT SI interference test (Prop ID 2173) if the Delta Plan interference tests are scheduled. If desired, a subset of this proposal could be used as the GHRS carrousel motion segment of the SI interference test. Operation of G270M at 1970 Angstroms, outside of its normal operating wavelength range, is intentional. Lines 2,3,16,17: each must be a continuous 4 minute exposure. Lines (4-6),(7- 9),(18-20),(21-23) must be performed in sequence within each group. Repeats (10,11,24,25) may be scheduled back to back or over several days if necessary. No restrictions on the execution of the 4 tests with respect to each other. Lines 12,13,26,27: the WSCAN series should each be performed without interruption if possible. There is no necessary time relationship bwtween the four scans though. Lines 14,28: the 50 repeated exposures should be made within one orbit if at all possible, but the intervals between them need not be uniform. There is no necessary connection between 14 and 28. The side 2 observations, lines 1-14 must be regarded as minimum plan SV tests. All exposures use the internal lamp. There is no Target List with this proposal. I have assumed that all internal tests can be performed as parallel operations. Only parallel observing time has been requested. We request that all of the GHRS engineering data obtained during this test be captured and made available to us. We need to examine the temperature data as part of the image stability analysis. Parallel S/C mode observations are requested. The "time per exposure" of the S/C parallel observations is an estimate of the GHRS exp.time plus some pad. If scheduling stretches the observations, we request that the S/C mode be stretched to span the same time interval as the GHRS data. SV Minimum Plan: lines 1-14, lines 27.5-28 SV Delta Plan: lines 15-27 Guiding Tolerance: None - internal test only ------------------------------------------------------------------------------------ 7. Data reduction and analysis plans. 1. Settling times: Measure times from acquisition of Fine JTrack Lock signal to stable image position after each carrousel movement. Compile statistics and recommend delay time for use in shortcut algorithm. 2. FPSPLIT timing: Compare time tag signals from each observation to infer carrousel overhead times. Cross correlate all images taken at a common carrousel position to measure repeatability. Compare line widths to guage adequacy of settling time. 3. WSCAN timing. Compare time tags to infer carrousel overhead times. Compile atlas of SC2 lamp spectrum. Derive dispersion constants, Y deflections and resolving powers. 4. Image stability: Use SPYBAL offsets to monitor Y position. Cross correlate spectra to measure X position. Analyze as functions of time and G-HRS temperatures and gradients. Coadd profiles to measure wings of Echelle scatted light function. Measure temperatures and temperature gradients as functions of time. Eaxamine possible correlations between image drifts or displacements with thermal conditions. ------------------------------------------------------------------------------------ 10. Resources to be supplied by investigator's institution(s). test personnel travel support publication support data analysis facilities ------------------------------------------------------------------------------------ 11. Address Information Name: DENNIS C. EBBETS Category: PI Institution: BALL AEROSPACE SYSTEMS GROUP Address: P.O.BOX 1062, FT-3 City: BOULDER State: CO Zip Code: 80306 Country: USA Telephone: 303-939-5964 Telex (or e-mail): ------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 2168c [ 5] ------------------------------------------------------------------------------------------------------------------------------------ 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 ------------------------------------------------------------------------------------------------------------------------------------ 0.5 DARK S/C DATA NONE 1 2M 1 PAR WITH 1 CYCLE 0 / 0.5-28 Comments: INTENT IS FOR S/C MODE ENG. DATA TO SPAN FULL DURATION OF GHRS OBS. IF SCHEDULING STRETCHES OBS., PLEASE ADJUST ALL S/C MODE DURATION. SEE G.F. SECTION 5. ------------------------------------------------------------------------------------------------------------------------------------ 1 WAVE HRS ACCUM SC2 G270M 3050 DOPPLER=OFF 1 16S 9 CALIB FOR 2,3 STEP-PATT=3 COMB=FOUR Comments: COMPUTE AND APPLY NEW SPYBAL OFFSET. ------------------------------------------------------------------------------------------------------------------------------------ 1.5 DARK S/C DATA NONE 1 5M 1 PAR WITH 2 ------------------------------------------------------------------------------------------------------------------------------------ 2 WAVE HRS RAPID SC2 G270M 3078.8 SAMPLE-TIME=0.2 1 240S 9 Comments: INCREASE ENCODER POSITION BY 4 STEPS EVERY 15 SECONDS FOR 16 TIMES. ------------------------------------------------------------------------------------------------------------------------------------ 2.5 DARK S/C DATA NONE 1 5M 1 PAR WITH 3 ------------------------------------------------------------------------------------------------------------------------------------ 3 WAVE HRS RAPID SC2 G270M 3030.3 SAMPLE-TIME=0.2 1 240S 9 Comments: DECREASE ENCODER POSITION BY 4 STEPS EVERY 15 SECONDS FOR 16 TIMES. LINES 1-3 DESCRIBE THE SETTLING TIME TEST FOR SIDE 2. ------------------------------------------------------------------------------------------------------------------------------------ 3.5 DEF DARK S/C DATA NONE 1 12M 1 PAR WITH 4 G4FPL ------------------------------------------------------------------------------------------------------------------------------------ 4 DEF WAVE HRS ACCUM SC2 G270M 1970 DOPPLER=OFF 1 54.4S 9 SEQ 4-6 NO GAP G4FPL STEP-PATT=5 FP-SPLIT=STD COMB=TWO ------------------------------------------------------------------------------------------------------------------------------------ 5 ^ ^ ^ ^ ^ ^ 2490 ^ ^ ^ 9 ------------------------------------------------------------------------------------------------------------------------------------ 6 ^ ^ ^ ^ ^ ^ 3050 ^ ^ 9 Comments: FOR 4-6, USE "FULL STABILITY CHECK" CARROUSEL ALGORITHM. ------------------------------------------------------------------------------------------------------------------------------------ 6.5 DEF DARK S/C DATA NONE 1 12M 1 PAR WITH 7 G4FPS ------------------------------------------------------------------------------------------------------------------------------------ 7 DEF WAVE HRS ACCUM SC2 G270M 1970 DOPPLER=OFF 1 54.4S 9 SEQ 7-9 NO GAP G4FPS STEP-PATT=5 FP-SPLIT=STD COMB=TWO ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 2168c [ 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 ------------------------------------------------------------------------------------------------------------------------------------ 8 DEF WAVE HRS ACCUM SC2 G270M 2490 DOPPLER=OFF 1 54.4S 9 SEQ 7-9 NO GAP G4FPS STEP-PATT=5 FP-SPLIT=STD COMB=TWO ------------------------------------------------------------------------------------------------------------------------------------ 9 ^ ^ ^ ^ ^ ^ 3050 ^ 1 ^ ^ ^ Comments: FOR 7-9, USE "SHORTCUT ALGORITHM" ------------------------------------------------------------------------------------------------------------------------------------ 10 USE REPEAT 10 EVERY 1D G4FPL +/- 1.0D FOR 1 MORE TIMES ------------------------------------------------------------------------------------------------------------------------------------ 11 USE REPEAT 11 EVERY 1D G4FPS +/-1.0D FOR 1 MORE TIMES Comments: LINES 4-11 DESCRIBE THE FPSPLIT TIMING TEST FOR SIDE 2. ------------------------------------------------------------------------------------------------------------------------------------ 12 WAVE HRS WSCAN SC2 G160M 1190- DOPPLER=OFF 1 979.2S 9 1910 STEP-PATT=5 COMB=TWO WAVE-STEP=20 Comments: USE "FULL STABILITY CHECK" FOR 12 CENTRAL WAVELENGTHS= 1200, 1220,1240...1900 LINES 12-13. 36 CARROUSEL POSITIONS. ------------------------------------------------------------------------------------------------------------------------------------ 13 WAVE HRS WSCAN SC2 G160M 1190- DOPPLER=OFF 1 979.2S 9 1910 STEP-PATT=5 COMB=TWO WAVE-STEP=20 Comments: USE "SHORTCUT ALGORITHM" FOR 13 36 CARROUSEL POSITIONS. ------------------------------------------------------------------------------------------------------------------------------------ 13.5 DARK S/C DATA NONE 1 50M 1 PAR WITH 14 ------------------------------------------------------------------------------------------------------------------------------------ 14 WAVE HRS ACCUM SC2 ECH-B18 3064 DOPPLER=OFF 150 13.6S 9 STEP-PATT=7 COMB=TWO Comments: GROUP 14 WITHIN 90M; LINE 14 DESCRIBES IMAGE STABILITY TEST FOR SIDE 2. COMPUTE AND APPLY NEW SPYBAL EACH EXP. ------------------------------------------------------------------------------------------------------------------------------------ 15 WAVE HRS ACCUM SC2 G140M 1510 DOPPLER=OFF 1 16S 9 CALIB FOR 16,17 STEP-PATT=3 COND IF SV DELTA COMB=FOUR PLAN Comments: COMPUTE AND APPLY NEW SPYBAL OFFSET. ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 2168c [ 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 ------------------------------------------------------------------------------------------------------------------------------------ 15.5 DARK S/C DATA NONE 1 5M 1 PAR WITH 16 COND IF SV DELTA PLAN ------------------------------------------------------------------------------------------------------------------------------------ 16 WAVE HRS RAPID SC2 G140M 1517 SAMPLE-TIME=0.2 1 240S 9 COND IF SV DELTA PLAN Comments: INCREASE ENCODER POSITION BY 4 STEPS EVERY 15 SECONDS FOR 16 TIMES. ------------------------------------------------------------------------------------------------------------------------------------ 16.5 DARK S/C DATA NONE 1 5M 1 PAR WITH 17 COND IF SV DELTA PLAN ------------------------------------------------------------------------------------------------------------------------------------ 17 WAVE HRS RAPID SC2 G140M 1501 SAMPLE-TIME=0.2 1 240S 9 COND IF SV DELTA PLAN Comments: DECREASE ENCODER POSITION BY 4 STEPS EVERY 15 SECONDS FOR 16 TIMES. LINES 15-17 DESCRIBE THE SETTLING TIME TEST FOR SIDE 1. ------------------------------------------------------------------------------------------------------------------------------------ 17.5 DEF DARK S/C DATA NONE 1 12M 1 PAR WITH 18 G1FPL ------------------------------------------------------------------------------------------------------------------------------------ 18 DEF WAVE HRS ACCUM SC2 G140M 1250 DOPPLER=OFF 1 54.4S 9 SEQ 18-20 NO GAP G1FPL STEP-PATT=5 FP-SPLIT=STD COMB=TWO ------------------------------------------------------------------------------------------------------------------------------------ 19 ^ ^ ^ ^ ^ ^ 1510 ^ ^ ^ ^ ^ ------------------------------------------------------------------------------------------------------------------------------------ 20 DEF WAVE HRS ACCUM SC2 G140M 1775 DOPPLER=OFF 1 54.4S 9 SEQ 18-20 NO GAP G1FPL STEP-PATT=5 FP-SPLIT=STD COMB=TWO Comments: USE "FULL STABILITY CHECK" FOR 18-20 ------------------------------------------------------------------------------------------------------------------------------------ 20.5 DEF DARK S/C DATA NONE 1 12M 1 PAR WITH 21 G1FPS ------------------------------------------------------------------------------------------------------------------------------------ 21 DEF WAVE HRS ACCUM SC2 G140M 1250 DOPPLER=OFF 1 54.4S 9 SEQ 21-23 NO GAP G1FPS STEP-PATT=5 FP-SPLIT=STD COMB=TWO ------------------------------------------------------------------------------------------------------------------------------------ 22 DEF WAVE HRS ACCUM SC2 G140M 1510 DOPPLER=OFF 1 54.4S 9 SEQ 21-23 NO GAP G1FPS STEP-PATT=5 FP-SPLIT=STD COMB=TWO ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 2168c [ 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 ------------------------------------------------------------------------------------------------------------------------------------ 23 DEF WAVE HRS ACCUM SC2 G140M 1775 DOPPLER=OFF 1 54.4S 9 SEQ 21-23 NO GAP G1FPS STEP-PATT=5 FP-SPLIT=STD COMB=TWO Comments: USE "SHORTCUT ALGORITHM" FOR 21 -23 ------------------------------------------------------------------------------------------------------------------------------------ 24 USE REPEAT 24 EVERY 1D G1FPL +/- 0.5D FOR 3 MORE TIMES COND IF SV DELTA PLAN ------------------------------------------------------------------------------------------------------------------------------------ 25 USE REPEAT 25 EVERY 1D G1FPS +/-0.5D FOR 3 MORE TIMES COND IF SV DELTA PLAN Comments: LINES 18-25 DESCRIBE THE FPSPLIT TIMING TEST FOR SIDE 1. ------------------------------------------------------------------------------------------------------------------------------------ 26 WAVE HRS WSCAN SC2 G140M 1142.5- DOPPLER=OFF 1 843.2S 9 COND IF SV DELTA 1607.5 STEP-PATT=5 PLAN COMB=TWO WAVE-STEP=15 Comments: USE "FULL STABILITY CHECK" FOR 26. CENTRAL WAVELENGTHS=1150, 1165, 1180...1600 LINES 26,27. 31 CARROUSEL POSITIONS. ------------------------------------------------------------------------------------------------------------------------------------ 27 WAVE HRS WSCAN SC2 G140M 1142.5- DOPPLER=OFF 1 843.2S 9 COND IF SV DELTA 1607.5 STEP-PATT=5 PLAN COMB=TWO WAVE-STEP=15 Comments: USE "SHORTCUT ALGORITHM" FOR 27. LINES 26&27 DESCRIBE WSCAN TIMING TEST FOR SIDE 1. 31 CARROUSEL POSITIONS. ------------------------------------------------------------------------------------------------------------------------------------ 27.5 DARK S/C DATA NONE 1 50M 1 PAR WITH 28 ------------------------------------------------------------------------------------------------------------------------------------ 28 WAVE HRS ACCUM SC2 ECH-A37 1509 DOPPLER=OFF 150 13.6S 9 STEP-PATT=7 COMB=TWO Comments: LINE 28 DESCRIBES IMAGE STABILITY TEST FOR SIDE 1. COMPUTE AND APPLY NEW SPYBAL EACH EXP. 27.5 AND 28 ARE SV MINIMUM PLAN TESTS. ------------------------------------------------------------------------------------------------------------------------------------ Summary Form for Proposal 2168c [ 9] Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations S/C HRS ^ ------------------------------------------------------------------------------------------------------------------------------------ Opmodes DATA ACCUM RAPID ^ WSCAN ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters DOPPLER=OFF STEP-PATT=3 COMB=FOUR SAMPLE-TIME=0.2 STEP-PATT=5 FP-SPLIT=STD COMB=TWO WAVE-STEP=20 STEP-PATT=7 WAVE-STEP=15 ------------------------------------------------------------------------------------------------------------------------------------ Proposal for SV/HRS ------------------------------------------------------------------------------------------------------------------------------------ S/C Hours ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category ------------------------------------------------------------------------------------------------------------------------------------ Scientific Sub-category ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PAR WITH 1; CYCLE 0 / 0.5-28; CALIB FOR 2,3; PAR WITH 2; PAR WITH 3; PAR WITH 4; SEQ 4-6 NO GAP PAR WITH 7; SEQ 7-9 NO GAP; ^ REPEAT 10 EVERY 1D +/- 1.0D FOR 1 MORE TIMES; REPEAT 11 EVERY 1D +/-1.0D FOR 1 MORE TIMES; PAR WITH 14; CALIB FOR 16,17; COND IF SV DELTA PLAN; PAR WITH 16; PAR WITH 17; PAR WITH 18; SEQ 18-20 NO GAP; PAR WITH 21; SEQ 21-23 NO GAP; REPEAT 24 EVERY 1D +/- 0.5D FOR 3 MORE TIMES; REPEAT 25 EVERY 1D +/-0.5D PAR WITH 28; ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements G270M ^ G160M ECH-B18 G140M ECH-A37 ------------------------------------------------------------------------------------------------------------------------------------ Target Names ------------------------------------------------------------------------------------------------------------------------------------