8539( 38) - 07/15/99 10:08 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 8539 Version: 38 Check-in Date: 15-Jul-1999 10:07:35 1.Proposal Title: Using the Impact of the Lunar Prospector into a South Polar Cold Trap to Detect Water Ice on the Moon ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO/DD 8 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Edwin Barker University of Texas CoI: Alex Storrs STScI Y CoI: S. Alan Stern Southwest Research Institute, Boulder N CoI: David B. Goldstein University of Texas at Austin N CoI: R. Steven Nerem University of Texas at Austin N ------------------------------------------------------------------------------------ 5. Abstract Lunar Prospector data support the contention that water ice reservoirs exist in the permanently shaded craters near the lunar poles. Yet questions remain about whether the detection is actually of water ice or is of hydrogen in some other form. As the Prospector orbiter reaches the end of its planned mission at the end of July, 1999, a controlled impact of the orbiter into a polar crater will be used to liberate a small amount of water vapor which may be detected by ground- and space-based observatories. A positive spectral detection of water vapor or its photo-dissociated byproduct, OH, would provide definite proof for the presence of water ice in the regolith. Our impact models include plume gas dynamics predict detectable OH column densities both during the initial plume development and after the accommodated OH exosphere has developed above the sunlit Lunar surface. The STIS CCD can provide the high spectral resolution needed to resolve the A-X(0-0) band of OH at 3085A f rom the solar spectrum reflected b y the lunar surface. Details of the modeling can be found in our recently published paper(Goldstein, etal. J.Geo.Phy. Res. Let. Vol 26 No. 12, June 15, 1999, pp.1653-57). Additional figures and supporting in formation is also available at http://www.ae.utexas.edu/~cfpl/lunar/ NASA has now approved our proposal for a controlled impact into a crater located at (+41E, -87.5S). We have worked out a deorbit scenario that will allow us to impact into the preferred crater on either July 30th or 30st UTC. ------------------------------------------------------------------------------------ 8539( 38) - 07/15/99 10:08 - [ 2] Observations Description ------------------------ We plan to obtain observations of the lunar background, impact OH plume and OH exosphere a few hours later at several Lunar latitudes.--visit #1-- Impact orbit acquire, offset to impact site, take as many background observations as possible, start Impact exposure at least 10 sec before predicted impact time, readout, offset into plume region via POS-TARG offsets, take 2 100s exposures, then move to target LIMB-SEQUENCE for background measure if time allows; then return to Impact site at 270 arcsec above site to catch fallback of plume at impacttime +17 minutes. Do background exposure only if time allows.-- visit #2- - following orbit, two exposures at North pole for OH background. Start sequence of exposure at limb (-50S) moving southward to South pole. obtain as many exposures at each latitude with as many pointings as possble within acquisition period.-- visit #3-- three to 4 orbits after impact (6-8hours) Start sequence of exposure at limb (-50S) moving southward to South pole. obtain as many exposures at each latitude with as many pointings as possble within acquisition period. Real Time Justification ----------------------- Lunar Prospector impact will occur at a given time (+/- few seconds) and OH exosphere will develop during next 8-12 hours. Calibration Justification ------------------------- Background OH exposures must be taken as no information is available at the predicted low levels of OH emision from the steady state Lunar exosphere. Additional Comments ------------------- Number of exposures and pointings along limb to be worked out to fit the available visibility time each orbit. Only part of the visits are defined at this time as the number depends on the actual availability. ------------------------------------------------------------------------------------ Data Distribution Paper Products: NO Media: ELECTRONIC Blocking Factor: 10 Ship To: PI_Address Ship Via: Email: ------------------------------------------------------------------------------------ 8539( 38) - 07/15/99 10:08 - [ 3] TARGET LIST Solar System Targets ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 1 | TARGET NAME: IMPACTSITE ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: OFFSET Impact crater (+41E, -87.5S) ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD=EARTH | STD=MOON | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | TYPE=PGRAPHIC,LONG=318,LAT=-87.7,ALT=37 | | ------------------------------------------------------------------------------------------------------------------------------------ DATA | COMMENTS | SURF-CONT(3085)=3.1+/-.4e-12 | Lunar limb is at -y end of STIS slit SURF-LINE(3079)=3.6+/-0.4e-16 | (~5 arcsec of 5 2arcsec SIZE=100 | slitlength)center of slit is SURF(V) = 4.17 | 20arcsec off limb as roll angle puts | slit ~20deg from vertical. Note that | this is indeed in the pl a | netographic frame: Copernicus is at | 15 deg, (15W)., as it should be ( | 41E=319Long confrimed again esb | 6/12). | Acquisition Uncertainty: 0 " | ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 3 | TARGET NAME: LIMB-90N ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: OFFSET background observation ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD=EARTH | STD=MOON | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | TYPE=POS_ANGLE,RAD=946,ANG=336,REF=NORTH | | ------------------------------------------------------------------------------------------------------------------------------------ DATA | COMMENTS | SURF-CONT(3085)=3.1+/-.4e-12 | Lunar limb is at +y end of STIS slit SURF-LINE(3079)=3.6+/-0.4e-16 | (~2arcsec of 52 = arcsec SIZE=100 | slitlength). Angle and radius offset SURF(V) = 4.17 | due to changing roll angle and fact | that slit is not ppd to lunar limb. | Target position approximate, does | not need to be revised for 31 July | obs. | 8539( 38) - 07/15/99 10:08 - [ 4] TARGET LIST Solar System Targets ------------------------------------------------------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 5 | TARGET NAME: LIMBSEQ2 ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: OFFSET exosphere observation ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD=EARTH | STD=MOON | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | TYPE=POS_ANGLE,RAD=938,ANG=116,REF=NORTH | | ------------------------------------------------------------------------------------------------------------------------------------ DATA | COMMENTS | SURF-CONT(3085)=3.1+/-.4e-12 | Lunar limb is at -y end of STIS slit SURF-LINE(3079)=3.6+/-0.4e-16 | (~2 arcsec of 5 2 arcsec SIZE=100 | slitlength). Angle and radius offset SURF(V) = 4.17 | due to changing roll angle and fact | that slit is not ppd to lunar limb. | Target revised for use in 31 July | obs. | ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 6 | TARGET NAME: OFFIMPACTS2 ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: OFFSET 270 arcsec above Impact site ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD=EARTH | STD=MOON | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | TYPE=POS_ANGLE,RAD=1025,ANG=156,REF=NORT | H | | ------------------------------------------------------------------------------------------------------------------------------------ DATA | COMMENTS | SURF-CONT(3085)=3.1+/-0.4e-12 | offset 270 arcsec from Lunar limb; - SURF-LINE(3079)=3.6+/-0.4e-16 | y end of STIS slit nearest to limb. SIZE=100 | Ephemeris uncertainty should allow SURF(V) = 4.17 | motion of one slit length. Target | adjusted for use 31 July obs. | sequence. | Ephemeris Uncertainty: 100 KM | Acquisition Uncertainty: 0 " | ------------------------------------------------------------------------------------------------------------------------------------ 8539( 38) - 07/15/99 10:08 - [ 5] Visit: 01 Visit Priority: Visit Requirements: ORIENT 220D TO 228D BETWEEN 31-Jul-1999:09:30:00.0 AND 31-Jul- 1999:10:20:00.0 PCS MODE GYRO SCHED 100% ON HOLD On Hold Comments: See detailed comments given for visit # 1, schedule this visit only on July 31st. Additional Comments: Three Orbit visit. Orbit 1: Observations of impact and subsequent plume. Gyro acquisition only-- blind pointing otherwise. If necessary, break IMPACTSITE observations so that at least one exposure comes before the actual time of impact, for comparison. Timing of impact can be varied by 5- 10 min. if necessary. Roll angle set to place slit about 16.5deg from vertical (336 for 10 h July 31st). ORIENT needs to be set as close to 218 as feasible for POS TARG to work. If time available at end of visibility period add IMPACTSITE observation. Orbit 2:Observations of exosphere along Lunar limb, Start with background level at N pole, and then move to -50S, and then -60 S,-70S and-80S via POS TARG moves. Gyro acquisition only-- blind pointing otherwise. Expect POS TARG slews to take 59s each. NEED TO ADD POS TARG MOVES TO -100S and -40S LATITUDE IF TIME AVAILABLE. Need max. off- nominal roll. Orbit 3: Observations of exosphere along Lunar limb, start with -50S and follow with -60S,-70S,-80S, -90S via POS TARG moves. Gyro acquisition only-- blind pointing otherwise. Expect POS TARG slews to take 59s each. NEED TO ADD POS TARG MOVES TO -100S and -40S IF TIME AVAILABLE. Need ORIENT as near to 218 as feasible for POS TARG to work. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 5 WAVE STIS/C ACCUM 52X0.2 G430M 3165 1 DEF SEQ 5-40 NON-INT SAME CD OBSET 5-40 Comments: Do we need to specify a LAMP with this exposure? ------------------------------------------------------------------------------------------------------------------------------------ 10 IMPACTSITE STIS/C ACCUM 52X0.2 G430M 3165 BINAXIS1=1,BINAXIS2=4,WAVECAL=NO, 1 400 S CD CR-SPLIT=4 Comments: V=4.17 /arcsec**2; Background exposures prior to impact ------------------------------------------------------------------------------------------------------------------------------------ 20 IMPACTSITE STIS/C ACCUM 52X0.2 G430M 3165 BINAXIS1=1,BINAXIS2=4,CR-SPLIT=6 1 600 S CD Comments: Need for single (110sec) exposure so CR-Split =NO. Impact occurs within this exposure, need to be able to start e xposure about 10 second s before predicted impact time. ------------------------------------------------------------------------------------------------------------------------------------ 30 IMPACTSITE STIS/C ACCUM 52X0.2 G430M 3165 BINAXIS1=1,BINAXIS2=4,CR-SPLIT=NO 1 100 S POS TARG -59,-129 CD Comments: Need for single exposure so CR-Split=NO. This exposure is after impact and offset in plume direction to chase the high density shell, offset=(1km/s*time since impact*arsec/km) modif ied by slit angle from vertical 16.5 degrees. Poinitng 143 arcsec from impact site. ------------------------------------------------------------------------------------------------------------------------------------ 8539( 38) - 07/15/99 10:08 - [ 6] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 40 OFFIMPACTS2 STIS/C ACCUM 52X0.2 G430M 3165 BINAXIS1=1,BINAXIS2=4,CR-SPLIT=3 1 300 S REQ EPHEM CORR MOON2 CD Comments: Obs. 270 arcsec above impact sight to see fallback of plume. Need to sechedule as late in visibility period as possible, at least 17 min (17-20 min is ok) after impact (has assumption of plume speed as main uncertainty). May need to fine tune pointing with reuse offset. ------------------------------------------------------------------------------------------------------------------------------------ 60 WAVE STIS/C ACCUM 52X0.2 G430M 3165 1 DEF SAME OBSET 60-120 CD Comments: Do we need to specify a LAMP with the exp.? ------------------------------------------------------------------------------------------------------------------------------------ 70 LIMB-90N STIS/C ACCUM 52X0.2 G430M 3165 BINAXIS1=1,BINAXIS2=4 1 360 S CD Comments: Background exosphere at North pole. ------------------------------------------------------------------------------------------------------------------------------------ 80 LIMBSEQ2 STIS/C ACCUM 52X0.2 G430M 3165 BINAXIS1=1,BINAXIS2=4 1 160 S CD Comments: Exosphere, slit above -56S latitude on limb. ------------------------------------------------------------------------------------------------------------------------------------ 90 LIMBSEQ2 STIS/C ACCUM 52X0.2 G430M 3165 BINAXIS1=1,BINAXIS2=4 1 160 S POS TARG 74,-148 CD Comments: Exosphere observation, slit above -60S latitude on limb. ------------------------------------------------------------------------------------------------------------------------------------ 100 LIMBSEQ2 STIS/C ACCUM 52X0.2 G430M 3165 BINAXIS1=1,BINAXIS2=4 1 160 S POS TARG 174,-279 CD Comments: Exosphere; slit above -70S latitude on limb. ------------------------------------------------------------------------------------------------------------------------------------ 110 LIMBSEQ2 STIS/C ACCUM 52X0.2 G430M 3165 BINAXIS1=1,BINAXIS2=4 1 160 S POS TARG 293,-391 CD Comments: Exosphere; slit is above -80S latitude on limb. ------------------------------------------------------------------------------------------------------------------------------------ 120 LIMBSEQ2 STIS/C ACCUM 52X0.2 G430M 3165 BINAXIS1=1,BINAXIS2=4 1 160 S POS TARG 435,-476 END CD ORBIT Comments: Exosphere; slit is above -90S latitude on limb. ------------------------------------------------------------------------------------------------------------------------------------ 130 WAVE STIS/C ACCUM 52X0.2 G430M 3165 1 DEF SAME OBSET 130-180 CD Comments: Do we need to specify a LAMP with this exposure? ------------------------------------------------------------------------------------------------------------------------------------ 140 LIMBSEQ2 STIS/C ACCUM 52X0.2 G430M 3165 BINAXIS1=1,BINAXIS2=4,CR-SPLIT=3 1 300 S CD Comments: Exosphere; slit is above -50S latitude on limb. ------------------------------------------------------------------------------------------------------------------------------------ 8539( 38) - 07/15/99 10:08 - [ 7] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 150 LIMBSEQ2 STIS/C ACCUM 52X0.2 G430M 3165 BINAXIS1=1,BINAXIS2=4,CR-SPLIT=3 1 300 S POS TARG 74,-148 CD Comments: Exosphere; slit is above -60S latitude on Limb. ------------------------------------------------------------------------------------------------------------------------------------ 160 LIMBSEQ2 STIS/C ACCUM 52X0.2 G430M 3165 CR-SPLIT=3,BINAXIS1=1,BINAXIS2=4 1 300 S POS TARG 174,-279 CD Comments: Exosphere; slit is above -70S latitude on Limb. ------------------------------------------------------------------------------------------------------------------------------------ 170 LIMBSEQ2 STIS/C ACCUM 52X0.2 G430M 3165 CR-SPLIT=3,BINAXIS1=1,BINAXIS2=4 1 300 S POS TARG 293,-391 CD Comments: Exosphere; slit is above -80S latitude on Limb. ------------------------------------------------------------------------------------------------------------------------------------ 180 LIMBSEQ2 STIS/C ACCUM 52X0.2 G430M 3165 CR-SPLIT=3,BINAXIS1=1,BINAXIS2=4 1 300 S POS TARG 435,-476 CD Comments: Exosphere; slit is above -90S latitude on Limb. ------------------------------------------------------------------------------------------------------------------------------------ 8539( 38) - 07/15/99 10:08 - [ 8] Summary Form for Proposal 8539 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures 52X0.2 ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters BINAXIS1=1 BINAXIS2=4 WAVECAL=NO CR-SPLIT=4 CR-SPLIT=6 CR-SPLIT=NO CR-SPLIT=3 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO/DD ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ORIENT 220D TO 228D BETWEEN 31-Jul-1999 09 30 00.0 AND 31-Jul-1999 10 20 00.0 PCS MODE GYRO SCHED 100% ON HOLD SEQ 5-40 NON-INT SAME OBSET 5-40 POS TARG -59,-129 REQ EPHEM CORR MOON2 SAME OBSET 60-120 POS TARG 74,-148 POS TARG 174,-279 POS TARG 293,-391 POS TARG 435,-476 END ORBIT SAME OBSET 130-180 POS TARG 435,-476 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements G430M ------------------------------------------------------------------------------------------------------------------------------------ Target Names WAVE IMPACTSITE OFFIMPACTS2 LIMB-90N LIMBSEQ2 ------------------------------------------------------------------------------------------------------------------------------------ Wavelengths 3165 ------------------------------------------------------------------------------------------------------------------------------------