7315( 19) - 07/16/99 19:00 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 7315 Version: 19 Check-in Date: 16-Jul-1999 18:59:06 1.Proposal Title: A Campaign to Determine the CO and CO2 Abundances in Cometary Nuclei ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 7 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Paul Feldman The Johns Hopkins University CoI: Michael F. A'Hearn University of Maryland N CoI: Michel C. Festou Observatoire Midi-Pyr'e n'e es N CoI: Jason B. McPhate The Johns Hopkins University N CoI: Gian Paolo Tozzi Osservatorio Astrofisico di Arcetri N CoI: Harold A. Weaver The Johns Hopkins University N ------------------------------------------------------------------------------------ 5. Abstract We propose the continuation of a campaign to determine the abundances of CO and CO2, relative to H2O, in a significant sample of comets, both targets of opportunity and periodic comets, over the next three years to address fundamental issues in the composition of cometary nuclei. The campaign began in Cycle 6, using the FOS to obtain spectra of comets 22P/Kopff and C/1996 B2 (Hyakutake), the latter in June 1996 when the comet was 0.94 AU from the sun and 1.12 AU from Earth. We anticipate that there may be two or three suitable candidates (periodic plus ToO) each year. For Cycle 7, we have identified Comet 1999 H1 (Lee), a newly-discovered object, as our target in June 1999. ------------------------------------------------------------------------------------ 7315( 19) - 07/16/99 19:00 - [ 2] Observations Description ------------------------ The original Phase I submission proposed two targets, a ToO comet and the periodic comet 55P/Tempel-Tuttle. The TAC was concerned that the latter may not be bright enough (it has not been well observed in the past), allocated 6 orbits to the proposal and left it to the PI team to decide between the two. We decided in late 1997 that Tempel-Tuttle was not bright enough to satisfy our objectives, so we are using all 6 orbits on the moderately bright, newly- discovered comet C/1999 H1 (Lee). We had originally proposed low resolution observations with G230L to obtain the brightnesses of all of the relevant cometary emissions. In the event of a brighter comet, we would have added several G230M and G140M exposures at higher spectral resolution in narrower wavelength bands to measure line shapes of several strong CO Cameron and Fourth Positive bands in order to separate the `hot' and `cold' excitation sources of the Cameron bands. We have divided the six orbits into three groups of two orbits each, each group corresponding to a different spectral range. The three groups are (all use the STIS-MAMA): 1. G230L, with the 0.5" slit, will span the wide spectral band from 1570 to 3180 A at 33 A resolution and will provide measurements of the CO Cameron and Fourth Positive (primarily the strong 0, 1 band at 1597 A) bands, CI 1931 and the strong OH (0, 0) band at 3085 A, as well as their spatial distributions near the nucleus. Thus a single spectrum will provide all of the data needed to address the primary objectives outlined above. 2. The additional initial objective of obtaining higher resolution spectra of selected CO Cameron and Fourth Positive bands with the G230M and G140M gratings will be replaced with a single G230M spectrum of the strongest Cameron band, the (0, 0) band near 2060 A. Using the 0.5" wide slit will give a spectral resolution of 1.4 A which should be sufficient to separate the `hot' and `cold' components, corresponding to photodissociation of CO2 and electron excitation of CO, respectively. However, for a fainter comet we will employ the 2" wide slit (spectral resolution 6 A) for higher sensitivity. 3. Because of the sharp drop in sensitivity of G230L below 2000 A, the Fourth Positive system of CO will be more effectively measured with G140L. Either the 0.2" slit (spectral resolution 5 A) or the 0.5" slit (spectral resolution 12.5 A), or the 2" slit (spectral resolution 50 A) will be used depending on the expected brightness of the emissions. For target acquisition we will use the STIS/CCD configuration with the F28X50LP filter and treat the comet as a point source (ACQTYPE=POINT). Although comets are extended sources, the spatial distribution of the dust coma (the principal source of the visual emission) is sharply peaked near the nucleus and there is always a single pixel (or two pixels) that dominate in WFPC2 Planetary Camera images of comets (in some cases the nucleus has been photometrically resolved). Thus, the 3 * 3 checkbox used for point source acquisitions should easily locate the center of brightness of the comet and place it at the center of the spectrograph aperture. The timeline for the observations is as follows (the lines give the activities that will be executed in EACH orbit). Visits 1-2 : ACQ CCD image + G140L MAMA exposures Visits 3-4 : ACQ CCD image + G230L MAMA exposures Visits 5-6 : ACQ CCD image + G230LB exposures + CCD image (confirmation) Each group of two visits has its own ephemeris offset command in case they are separated by many hours. However, we would like all 6 visits to be executed as close to consecutive as possible, in which case the ephemeris offset commands for all groups will be identical. The value specified for the EPHEM_UNCERT keyword corresponds to an angular displacement of 10 arcsec. By the time the GS selection is made for this program, we expect the ephemeris uncertainty at the time of the observations to be about 5 arcsec. We use a somewhat larger value to be on the conservative side. UPDATE FOR REPEAT OBSERVATIONS IN AUGUST 1999: We are repeating visits 1, 2, 3, and 4 with the new visits being numbered 11, 21, 31, and 41, respectively. All observations must be made under FGS control to ensure that the STIS/MAMA observations do not get terminated early. In order to increase the scheduling flexibility, we have removed all of the formal timing requirements on the visits. However, it is best if these new visits be scheduled sequentially (i.e., first do 11, then 21, 31, and 41) and that all four visits be executed within 1 calendar day. We can tolerate single GS tracking, if necessary. Real Time Justification ----------------------- Since the ephemerides of Target of Opportunity comets are usually not well known (uncertainties of several arc-seconds are not uncommon), it is necessary to uplink an ephemeris correction before any of the spectroscopic measurements are made. This has been done very successfully during previous HST cometary observations. Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 7315( 19) - 07/16/99 19:00 - [ 3] Data Distribution Paper Products: Media: ELECTRONIC Blocking Factor: 10 Ship To: PI_Address Ship Via: Email: ------------------------------------------------------------------------------------ 7315( 19) - 07/16/99 19:00 - [ 4] TARGET LIST Solar System Targets ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 1 | TARGET NAME: COMET-LEE ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: COMET 1999H1-LEE ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | TYPE=COMET,Q=0.707314274,E=0.998788984,I | =149.3503289,O=162.6724549,W=40.8031036, | T = 11-Jul- | 1999:04:45:53.0,EQUINOX=J2000,EPOCH=01- | Jul-1999 | | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | ------------------------------------------------------------------------------------------------------------------------------------ DATA | COMMENTS | V = 15+/-2 | V-mag is for the nucleus. The coma B-V = 0.8 | will contribute very little flux to V-R = 0.4 | the peak pixel. These elements are | from JPL17 and should be used for | final scheduling. | Ephemeris Uncertainty: 17400 KM | Acquisition Uncertainty: 10 " | ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 2 | TARGET NAME: COMET-LEE2 ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: COMET 1999H1-LEE-2 ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | TYPE=COMET,Q=0.708050682,E=0.999689494,I | =149.353013,O=162.6504496,W=40.7067747,T | = 11-Jul- | 1999:04:10:17.0,EQUINOX=J2000,EPOCH=01- | Jul-1999 | | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | ------------------------------------------------------------------------------------------------------------------------------------ DATA | COMMENTS | V = 15+/-2 | V-mag is for the nucleus. The coma B-V = 0.8 | will contribute very little flux to V-R = 0.4 | the peak pixel. These elements are | from JPL22. | Ephemeris Uncertainty: 20000 KM | Acquisition Uncertainty: 10 " | 7315( 19) - 07/16/99 19:00 - [ 5] TARGET LIST Solar System Targets ------------------------------------------------------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------------------------------------------------------ 7315( 19) - 07/16/99 19:00 - [ 6] Visit: 01 Visit Priority: Visit Requirements: SEQ 1-2 WITHIN 100m SCHED 100% DROP TO GYRO IF NECESSARY On Hold Comments: Additional Comments: First of G140L group Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 11 COMET-LEE STIS/C ACQ F28X50L MIRROR 1 10 S REQ EPHEM CORR OFF1 CD P ONBOARD ACQ FOR 12 SEQ 11-12 NON-INT Comments: TA sequence ------------------------------------------------------------------------------------------------------------------------------------ 12 COMET-LEE STIS/F TIME-TA 52X2 G140L 1425 BUFFER-TIME=5000 1 1800 S REQ EPHEM CORR OFF1 UV-MAM G A Comments: Spectroscopic exposure during 1st MT track command ------------------------------------------------------------------------------------------------------------------------------------ 7315( 19) - 07/16/99 19:00 - [ 7] Visit: 02 Visit Priority: Visit Requirements: DROP TO GYRO IF NECESSARY SCHED 100% On Hold Comments: Additional Comments: Second of G140L group Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 21 COMET-LEE STIS/C ACQ F28X50L MIRROR 1 10 S REQ EPHEM CORR OFF2 CD P ONBOARD ACQ FOR 22-24 SEQ 21-24 NON-INT Comments: TA sequence ------------------------------------------------------------------------------------------------------------------------------------ 22 COMET-LEE STIS/F TIME-TA 52X2 G140L 1425 BUFFER-TIME=5000 1 1500 S REQ EPHEM CORR OFF2 UV-MAM G A Comments: Spectroscopic exposure during 1st MT track command ------------------------------------------------------------------------------------------------------------------------------------ 24 COMET-LEE STIS/C ACCUM F28X50L MIRROR CR-SPLIT=NO ,GAIN=4 1 30 S REQ EPHEM CORR OFF2 MAX CD P DUR 100% END ORBIT Comments: Verification image. ------------------------------------------------------------------------------------------------------------------------------------ 7315( 19) - 07/16/99 19:00 - [ 8] Visit: 03 Visit Priority: Visit Requirements: DROP TO GYRO IF NECESSARY SEQ 3-4 WITHIN 100m SCHED 100% On Hold Comments: Additional Comments: First of G230L group Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 31 COMET-LEE STIS/C ACQ F28X50L MIRROR 1 10 S REQ EPHEM CORR OFF3 CD P ONBOARD ACQ FOR 32 SEQ 31-32 NON-INT Comments: TA sequence ------------------------------------------------------------------------------------------------------------------------------------ 32 COMET-LEE STIS/N TIME-TA 52X0.5 G230L 2376 BUFFER-TIME=5000 1 1800 S REQ EPHEM CORR OFF3 UV-MAM G A Comments: Spectroscopic exposure during 1st MT track command ------------------------------------------------------------------------------------------------------------------------------------ 7315( 19) - 07/16/99 19:00 - [ 9] Visit: 04 Visit Priority: Visit Requirements: DROP TO GYRO IF NECESSARY SCHED 100% On Hold Comments: Additional Comments: Second of G230L group Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 41 COMET-LEE STIS/C ACQ F28X50L MIRROR 1 10 S REQ EPHEM CORR OFF4 CD P ONBOARD ACQ FOR 42-44 SEQ 41-44 NON-INT Comments: TA sequence ------------------------------------------------------------------------------------------------------------------------------------ 42 COMET-LEE STIS/N TIME-TA 52X0.5 G230L 2376 BUFFER-TIME=5000 1 1500 S REQ EPHEM CORR OFF4 UV-MAM G A Comments: Spectroscopic exposure during 1st MT track command ------------------------------------------------------------------------------------------------------------------------------------ 44 COMET-LEE STIS/C ACCUM F28X50L MIRROR CR-SPLIT=NO ,GAIN=4 1 30 S REQ EPHEM CORR OFF4 MAX CD P DUR 100% END ORBIT Comments: Verification image. ------------------------------------------------------------------------------------------------------------------------------------ 7315( 19) - 07/16/99 19:00 - [ 10] Visit: 05 Visit Priority: Visit Requirements: DROP TO GYRO IF NECESSARY SEQ 5-6 WITHIN 100m SCHED 100% On Hold Comments: Additional Comments: First of G230M group Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 51 COMET-LEE STIS/C ACQ F28X50L MIRROR 1 10 S REQ EPHEM CORR OFF5 CD P ONBOARD ACQ FOR 52 SEQ 51-52 NON-INT Comments: TA sequence ------------------------------------------------------------------------------------------------------------------------------------ 52 COMET-LEE STIS/N TIME-TA 52X2 G230M 2095 BUFFER-TIME=5000 1 1800 S REQ EPHEM CORR OFF5 UV-MAM G A Comments: Spectroscopic exposure during 1st MT track command ------------------------------------------------------------------------------------------------------------------------------------ 7315( 19) - 07/16/99 19:00 - [ 11] Visit: 06 Visit Priority: Visit Requirements: DROP TO GYRO IF NECESSARY SCHED 100% On Hold Comments: Additional Comments: Second of G230M group Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 61 COMET-LEE STIS/C ACQ F28X50L MIRROR 1 10 S REQ EPHEM CORR OFF6 CD P ONBOARD ACQ FOR 62-64 SEQ 61-64 NON-INT Comments: TA sequence ------------------------------------------------------------------------------------------------------------------------------------ 62 COMET-LEE STIS/N TIME-TA 52X2 G230M 2095 BUFFER-TIME=5000 1 1500 S REQ EPHEM CORR OFF6 UV-MAM G A Comments: Spectroscopic exposure during 1st MT track command ------------------------------------------------------------------------------------------------------------------------------------ 64 COMET-LEE STIS/C ACCUM F28X50L MIRROR CR-SPLIT=NO ,GAIN=4 1 30 S REQ EPHEM CORR OFF6 MAX CD P DUR 100% END ORBIT Comments: Verification image. ------------------------------------------------------------------------------------------------------------------------------------ 7315( 19) - 07/16/99 19:00 - [ 12] Visit: 11 Visit Priority: Visit Requirements: SCHED 100% between 20-Aug-1999:15:15:00 and 20-Aug-1999:16:10:00 between 21 -Aug-1999:07:20:00 and 21-Aug-1999:08:20:00 between 22-Aug-1999:05:55:00 and 22-Aug-1999:06:50:00 between 22-Aug-1999:10:45:00 and 22-Aug- 1999:11:40:00 between 23-Aug-1999:14:00:00 and 23-Aug-1999:14:55:00 On Hold Comments: Additional Comments: First of G140L group Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 11 COMET-LEE2 STIS/C ACQ F28X50L MIRROR 1 10 S REQ EPHEM CORR OFF11 CD P ONBOARD ACQ FOR 12 SEQ 11-12 NON-INT Comments: TA sequence ------------------------------------------------------------------------------------------------------------------------------------ 12 COMET-LEE2 STIS/F TIME-TA 52X2 G140L 1425 BUFFER-TIME=5000 1 1800 S REQ EPHEM CORR OFF11 UV-MAM G A Comments: Spectroscopic exposure during 1st MT track command ------------------------------------------------------------------------------------------------------------------------------------ 7315( 19) - 07/16/99 19:00 - [ 13] Visit: 21 Visit Priority: Visit Requirements: SCHED 100% between 20-Aug-1999:15:15:00 and 20-Aug-1999:16:10:00 between 21 -Aug-1999:07:20:00 and 21-Aug-1999:08:20:00 between 22-Aug-1999:05:55:00 and 22-Aug-1999:06:50:00 between 22-Aug-1999:10:45:00 and 22-Aug- 1999:11:40:00 between 23-Aug-1999:14:00:00 and 23-Aug-1999:14:55:00 On Hold Comments: Additional Comments: Second of G140L group Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 21 COMET-LEE2 STIS/C ACQ F28X50L MIRROR 1 10 S REQ EPHEM CORR OFF21 CD P ONBOARD ACQ FOR 22-24 SEQ 21-24 NON-INT Comments: TA sequence ------------------------------------------------------------------------------------------------------------------------------------ 22 COMET-LEE2 STIS/F TIME-TA 52X2 G140L 1425 BUFFER-TIME=5000 1 1500 S REQ EPHEM CORR OFF21 UV-MAM G A Comments: Spectroscopic exposure during 1st MT track command ------------------------------------------------------------------------------------------------------------------------------------ 24 COMET-LEE2 STIS/C ACCUM F28X50L MIRROR CR-SPLIT=NO ,GAIN=4 1 30 S REQ EPHEM CORR OFF21 MAX CD P DUR 100% END ORBIT Comments: Verification image. ------------------------------------------------------------------------------------------------------------------------------------ 7315( 19) - 07/16/99 19:00 - [ 14] Visit: 31 Visit Priority: Visit Requirements: SCHED 100% between 20-Aug-1999:15:15:00 and 20-Aug-1999:16:10:00 between 21 -Aug-1999:07:20:00 and 21-Aug-1999:08:20:00 between 22-Aug-1999:05:55:00 and 22-Aug-1999:06:50:00 between 22-Aug-1999:10:45:00 and 22-Aug- 1999:11:40:00 between 23-Aug-1999:14:00:00 and 23-Aug-1999:14:55:00 On Hold Comments: Additional Comments: First of G230L group Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 31 COMET-LEE2 STIS/C ACQ F28X50L MIRROR 1 10 S REQ EPHEM CORR OFF31 CD P ONBOARD ACQ FOR 32 SEQ 31-32 NON-INT Comments: TA sequence ------------------------------------------------------------------------------------------------------------------------------------ 32 COMET-LEE2 STIS/N TIME-TA 52X0.5 G230L 2376 BUFFER-TIME=5000 1 1800 S REQ EPHEM CORR OFF31 UV-MAM G A Comments: Spectroscopic exposure during 1st MT track command ------------------------------------------------------------------------------------------------------------------------------------ 7315( 19) - 07/16/99 19:00 - [ 15] Visit: 41 Visit Priority: Visit Requirements: SCHED 100% between 20-Aug-1999:15:15:00 and 20-Aug-1999:16:10:00 between 21 -Aug-1999:07:20:00 and 21-Aug-1999:08:20:00 between 22-Aug-1999:05:55:00 and 22-Aug-1999:06:50:00 between 22-Aug-1999:10:45:00 and 22-Aug- 1999:11:40:00 between 23-Aug-1999:14:00:00 and 23-Aug-1999:14:55:00 On Hold Comments: Additional Comments: Second of G230L group Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 41 COMET-LEE2 STIS/C ACQ F28X50L MIRROR 1 10 S REQ EPHEM CORR OFF41 CD P ONBOARD ACQ FOR 42-44 SEQ 41-44 NON-INT Comments: TA sequence ------------------------------------------------------------------------------------------------------------------------------------ 42 COMET-LEE2 STIS/N TIME-TA 52X0.5 G230L 2376 BUFFER-TIME=5000 1 1500 S REQ EPHEM CORR OFF41 UV-MAM G A Comments: Spectroscopic exposure during 1st MT track command ------------------------------------------------------------------------------------------------------------------------------------ 44 COMET-LEE2 STIS/C ACCUM F28X50L MIRROR CR-SPLIT=NO ,GAIN=4 1 30 S REQ EPHEM CORR OFF41 MAX CD P DUR 100% END ORBIT Comments: Verification image. ------------------------------------------------------------------------------------------------------------------------------------ 7315( 19) - 07/16/99 19:00 - [ 16] Summary Form for Proposal 7315 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures F28X50LP 52X2 52X0.5 ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD STIS/FUV-MAMA STIS/NUV-MAMA ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ TIME-TAG ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters BUFFER-TIME=5000 GAIN=4 CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements SEQ 1-2 WITHIN 100m SCHED 100% DROP TO GYRO IF NECESSARY REQ EPHEM CORR OFF1 ONBOARD ACQ FOR 12 SEQ 11-12 NON-INT REQ EPHEM CORR OFF1 DROP TO GYRO IF NECESSARY SCHED 100% REQ EPHEM CORR OFF2 ONBOARD ACQ FOR 22-24 SEQ 21-24 NON-INT REQ EPHEM CORR OFF2 REQ EPHEM CORR OFF2 MAX DUR 100% END ORBIT DROP TO GYRO IF NECESSARY SEQ 3-4 WITHIN 100m SCHED 100% REQ EPHEM CORR OFF3 ONBOARD ACQ FOR 32 SEQ 31-32 NON-INT REQ EPHEM CORR OFF3 REQ EPHEM CORR OFF4 ONBOARD ACQ FOR 42-44 SEQ 41-44 NON-INT REQ EPHEM CORR OFF4 REQ EPHEM CORR OFF4 MAX DUR 100% END ORBIT DROP TO GYRO IF NECESSARY SEQ 5-6 WITHIN 100m SCHED 100% REQ EPHEM CORR OFF5 ONBOARD ACQ FOR 52 SEQ 51-52 NON-INT REQ EPHEM CORR OFF5 REQ EPHEM CORR OFF6 ONBOARD ACQ FOR 62-64 SEQ 61-64 NON-INT REQ EPHEM CORR OFF6 REQ EPHEM CORR OFF6 MAX DUR 100% END ORBIT SCHED 100% between 20-Aug-1999 15 15 00 and 20-Aug-1999 16 10 00 between 21-Aug-1999 07 20 00 and 21-Aug-1999 08 20 00 between 22-Aug-1999 05 55 00 and 22-Aug-1999 06 50 00 between 22-Aug-1999 10 45 00 and 22-Aug-1999 11 40 00 between 23-Aug-1999 14 00 00 and 23-Aug-1999 14 55 00 REQ EPHEM CORR OFF11 ONBOARD ACQ FOR 12 SEQ 11-12 NON-INT REQ EPHEM CORR OFF11 SCHED 100% between 20-Aug-1999 15 15 00 and 20-Aug-1999 16 10 00 between 21-Aug-1999 07 20 00 and 21-Aug-1999 08 20 00 between 22-Aug-1999 05 55 00 and 22-Aug-1999 06 50 00 between 22-Aug-1999 10 45 00 and 22-Aug-1999 11 40 00 between 23-Aug-1999 14 00 00 and 23-Aug-1999 14 55 00 REQ EPHEM CORR OFF21 ONBOARD ACQ FOR 22-24 SEQ 21-24 NON-INT REQ EPHEM CORR OFF21 REQ EPHEM CORR OFF21 MAX DUR 100% END ORBIT SCHED 100% between 20-Aug-1999 15 15 00 and 20-Aug-1999 16 10 00 between 21-Aug-1999 07 20 00 and 21-Aug-1999 08 20 00 between 22-Aug-1999 05 55 00 and 22-Aug-1999 06 50 00 between 22-Aug-1999 10 45 00 and 22-Aug-1999 11 40 00 between 23-Aug-1999 14 00 00 and 23-Aug-1999 14 55 00 REQ EPHEM CORR OFF31 ONBOARD ACQ FOR 32 SEQ 31-32 NON-INT REQ EPHEM CORR OFF31 SCHED 100% between 20-Aug-1999 15 15 00 and 20-Aug-1999 16 10 00 between 21-Aug-1999 07 20 00 and 21-Aug-1999 08 20 00 between 22-Aug-1999 05 55 00 and 22-Aug-1999 06 50 00 between 22-Aug-1999 10 45 00 and 22-Aug-1999 11 40 00 between 23-Aug-1999 14 00 00 and 23-Aug-1999 14 55 00 REQ EPHEM CORR OFF41 ONBOARD ACQ FOR 42-44 SEQ 41-44 NON-INT REQ EPHEM CORR OFF41 REQ EPHEM CORR OFF41 MAX DUR 100% END ORBIT ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR G140L G230L G230M ------------------------------------------------------------------------------------------------------------------------------------ Target Names COMET-LEE COMET-LEE2 ------------------------------------------------------------------------------------------------------------------------------------ Wavelengths 1425 2376 2095 ------------------------------------------------------------------------------------------------------------------------------------