Page 1 PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID 5438 Report Date: 18-Jul-95:17:23 Version: ********** Check-in Date: ********** 1.Proposal Title: IO'S ATMOSPHERE: UV SPECTROSCOPY OF NEUTRAL AND MOLECULAR COMPONENTS -- CYCLE 4 HIGH ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Proposal Type 5. Continuation ID SOLAR SYSTEM GO Sub Category SATELLITES ------------------------------------------------------------------------------------ 6. Principal Investigator Institution Country Telephone Dr. Gilda E. Ballester UNIVERSITY OF MICHIGAN USA 313-747-3670 ------------------------------------------------------------------------------------ 7. Abstract HST observations of Io's neutral O and S FUV emissions revealed a large intensity drop as Io goes into eclipse, inconsistent with excitation of an O and S corona by torus electrons as the main excitation mechanism. Alternatively, a collapse of the bulk SO2 atmosphere or an ionospheric process possibly damped by recombination may be involved. A limited S/N HST measure of the spatial dependence of the S emission has shown that it may extend to high altitudes, far from the expected peak SO2 density, and IUE data has shown an E/W intensity asymmetry which may be related to torus asymmetries. These two observations are hard to reconcile with the eclipse picture, and we propose to make a sequence of high S/N spatial scans of the FUV emissions to measure the spatial distributions of the excitation region and of the neutral corona, respectively with optically thin and thick emissions, and to resolve any torus dependence. New FOS G190H observations have finally detected a tenous, extended SO2 atmosphere on Io's trailing side. We propose to now observe the leading side, together with trailing side observations with improved S/N, to measure asymmetries in the SO2 abundances that may arise from the distributions of SO2 frost and volcanic sources, asymmetries in the atmospheric temperature possibly related to the Io/torus interaction, and temporal variations in Io's major atmospheric component. ------------------------------------------------------------------------------------ 8. Scientific Key Words: PLANETARY SATELLITE, PLASMA TORUS ------------------------------------------------------------------------------------ 9. Est obs time (hours) pri: 9.03 par: 0 10. Num targs pri: 6 par: 0 ------------------------------------------------------------------------------------ 11. Instruments requested: HRS FOS ------------------------------------------------------------------------------------ 12. Special sched req: Time Critical obs. ------------------------------------------------------------------------------------ Page 2 I. GENERAL FORM Proposal 5438 PI: Dr. Gilda E. Ballester Proposal Title: IO'S ATMOSPHERE: UV SPECTROSCOPY OF NEUTRAL AND MOLECULAR COMPONENTS -- CYCLE 4 HIGH ------------------------------------------------------------------------------------ 1. Proposers: Proposers Institution Country ESA ------------------------------------------------------------------------------------ Dr. Gilda E. Ballester 2660 USA John Clarke 2660 USA Joe Ajello 2370 USA Nick Schneider 1760 USA Darrell Strobel 2380 USA Melissa Mcgrath 3470 USA ------------------------------------------------------------------------------------ 3. Description of proposed observations. A series of spatial scans of Io's O and S emissions will be made with the G140L grating on GHRS and the 2x2 arc sec aperture. These will include pairs of E/W and N/S scans when Io is at west and east elongation, and when near superior conjunction for a perpendicular geometry and looking at Io's side facing Jupiter. These scans will have Io "inside" the torus densest region, and the dependence on the torus will be studied with another pair of scans at west elong. with Io "outside" the torus plane. The spectra will cover the OI optically thick and thin 1304 and 1356 A emissions, and the SI 1251 and 1479 A emissions, with thin emissions showing the excitation source distribution and thick emissions showing also the extension of Io's neutral corona. The S/N will be 6.5 times higher than for previous SI scans. As approved by the TAC, in case the GHRS side 1 is not successfully re-activated, we will make the scans with the FOS G130H and the 1.4x4.3 arcsec aper., with a slightly lower S/N but with better spectral resolution to detect large changes in the OI 1304 A line ratios. The red leak in G130H would require a 25 min. calibration exposure on Ganymede. We will also make FOS G190H exposures of Io's leading and trailing hemispheres with the 1.4x4.3 arcsec aper. to measure the atmospheric SO2 abundance at the time of the FUV scans and asymmetries due to volcanoes and SO2 frost. Due to the variability of the phenomena, all observations should be contemporaneous. Simultaneous ground based torus obs. are planned. Page 3 ------------------------------------------------------------------------------------ 4. Justification of need for HST observations. IUE, with typical 14-hr exposures, cannot make spatial scans. GTO WFPC 2 images of Io's FUV emissions will not resolve the optically thick and thin components, so our data will help the interpretation of these images. The low densities of Io's SO2 atmosphere are best sampled in the strong UV absorption bands at 2000 A, which can only be accessed with HST (the flux is too low for IUE). Our cycle 3 observations with FOS G190H and the 0.3 arc sec circular aperture were aimed at various regions on Io to measure large changes in the atmosphere/surface, but the S/N is not high enough to measure the temperature dependence of the emission, and the leading hemisphere will not be observed either. So far only ground-based millimeter observations can detect Io's atmospheric SO2 but mainly the hot, dense SO2 patches possibly related to volcanic regions, and not the low SO2 densities that HST can sample. On Galileo, only one of the UV instruments will be useful and our HST data will be used for the science planning of this mission due to reach Jupiter in late 1995 (the resolution of the second UV instrument is too low). Ground- based observations have been made of the OI 6300 A emission near Io, but such difficult observations do not give spatial information and do not sample the atmosphere directly, which makes our HST data unique. Besides torus electron excitation, the 6300 A emissions require an additional source involving SO/SO2 molecules but also depending on the torus, interesting for comparison with our data. ------------------------------------------------------------------------------------ 5. Description of special scheduling requirements. Dark time is essential for all the FUV spatial scans to avoid contamination by 1304 A airglow that would make interpretation of the scans difficult. Io must be acquired and its center determined to within roughly 0.10 arc sec. Because of temporal variability of Io's atmosphere and torus parameters, all the observations should be made close in time. Three sets of the GHRS scans will be made with Io inside the densest torus region as it crosses the torus plane around Sys. III longitude 292 deg., within +/- 45 deg. (the region around longitude 112 deg. has different characteristics). The fourth set of scans will be made with Io outside this region, when farthest from the plane around torus longitude 202 or 22 deg., within +/- 45 deg. The FOS/SO2 observations are assumed independent of the torus parameters. We have found an HST observing sequence spanning 2 orbits of Io that fits all above requisites. Each obs. is specified by Io's orbital phase and Jupiter's central meridian longitude (CML) defining the torus longitude where Io is embedded: No) OBS TYPE IO ORB PHASE JUPITER CML TORUS LONG OF IO 1) SO2 ~ W elong. ~270 2) SO2 ~E elong. ~90 3) scans ~W elong. ~270 22 +/- 45 292 +/- 45 "in" 4) scans ~W elong. ~270 112 +/- 45 22 +/- 45 "out" 5) scans near Sup.C. ~340 92 +/- 45 292 +/- 45 "in" 6) scans ~E elong. ~90 202 +/- 45 292 +/- 45 "in" ------------------------------------------------------------------------------------ 6. Description of special calibration exposures. Dark time is essential for all the FUV spatial scans due to potential contamination by 1304 airglow that makes the interpretation of the scans difficult. ------------------------------------------------------------------------------------ 8. Additional comments or special requests. None. Page 4 ------------------------------------------------------------------------------------ 9. Description of previous HST work. GO 2602 - "The Excitation of Atmospheres of Planetary Satellites" J. Clarke PI, J. Ajello and N. Schneider Co-I's -directly related. GO 2627 - "Io's Atmosphere and its Interaction with the Torus" Co-I's: M. McGrath, G. Ballester - directly related. GO 4600 - "FUV Spectroscopy of Io's Armosphere", J. Clarke PI, J. Ajello, N. Schneider, M. McGrath and many other unrelated GO programs on upper atmospheres of the outer planets, Venus, Mars and the ISM with J. Clarke or M.Mcgrath PI's or Co-I's and/or other Co-I's in the present program as Co-I's: GO 2393, 2602, 2603, 2625, 2627, 3511, 3616, 3617, 3618, 3862, 4600, ???, 4601, GO/AR 4604, as well and other new cycle 4 programs. The main results obtained from the related programs are: GO 2602: Excellent spectra of Io entering eclipse - resolved FUV emission region, found sharp decrease of line strength in shadow, characterizing the time scales, and near-UV albedo spectrum shows signature of surface properties, with possible evidence for varaible SO2 atmospheric columns. GO 2627: Executed in spring 1992 - best determination of spatial extent of FUV airglow. First 1600-2300 A albedo measurement with positive detection of Io's SO2 atmosphere showing a much thinner SO2 atmosphere than expected. GO 4600: Only few exposures could be successfully scheduled. FOS G190H small aperture exposures of the Pele region and a bright region on the trailing hemisphere show variations possibly from more SO2 frost in the bright region. ------------------------------------------------------------------------------------ 10. Resources to be supplied by investigator's institution(s). Complete computing facilities are in place and available within the Space Physics Research Lab. at the University of Michigan for use on this project. Two Sparcstations, including a Sun IPX procured with cycle 1 GO funding, and a VAX 8600 are available for this project and are connected via a local area network, in addition to the Michigan network MERIT, SPAN, and Internet. All Co-I's also have complete computing facilities at their institutions for use on this project. In addition, the laboratory work of J. Ajello and collaborators is proceeding with input from the HST data and with independent funding ------------------------------------------------------------------------------------ 11. Address Information Name: GILDA E. BALLESTER Category: PI Institution: 2660 Address: AOSS DEPT. City: ANN ARBOR State: MI Zip Code: 481092143 Country: USA Telephone: 313-747-3540 Telex (or e-mail): ------------------------------------------------------------------------------------ TARGET LIST b)Solar System Targets ID = 5438 [ 5] ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 1 | TARGET NAME: IO-SCAN-W-IN ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: SATELLITE IO ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD = JUPITER | STD = IO | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | OLG OF IO BETWEEN 240 300, CML OF | JUPITER FROM EARTH BETWEEN 337 67, | OLG OF JUPITER BETWEEN 330 30, | SEP OF EUROPA IO FROM EARTH GT 10", | SEP OF GANYMEDE IO FROM EARTH GT 10", | SEP OF CALLISTO IO FROM EARTH GT 10" | ------------------------------------------------------------------------------------------------------------------------------------ REF | DATA | COMMENTS | | 1 |SURF(V) = 5.0 +/- 0.5 | OBSERVE IO WITHIN +/- 30 DEGREES OF 2 |SIZE = 1.0 +/- .2 | WEST ELONGATION, WHEN INSIDE THE 3 |F-LINE(1304)=2.1 +/- 1E-13 | TORUS DENSE REGION AROUND LONGITUDE 4 |W-LINE(1304)=0.01 | 292, AND WHEN JUPITER IS NEAR | | OPPOSITION (PREFERABLY BEFORE | | OPPOSITION). | ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 2 | TARGET NAME: IO-SCAN-W-OUT ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: SATELLITE IO ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD = JUPITER | STD = IO | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | OLG OF IO BETWEEN 240 300, CML OF | JUPITER FROM EARTH BETWEEN 67 157, | OLG OF JUPITER BETWEEN 330 30, | SEP OF EUROPA IO FROM EARTH GT 10", | SEP OF GANYMEDE IO FROM EARTH GT 10", | SEP OF CALLISTO IO FROM EARTH GT 10" | ------------------------------------------------------------------------------------------------------------------------------------ REF | DATA | COMMENTS | | 1 |SURF(V) = 5.0 +/- 0.5 | OBSERVE IO WITHIN +/- 30 DEGREES OF 2 |SIZE = 1.0 +/- .2 | WEST ELONGATION, WHEN OUTSIDE THE 3 |F-LINE(1304)=2.1 +/- 1E-13 | TORUS DENSE REGION AROUND LONGITUDE 4 |W-LINE(1304)=0.01 | 22, AND WHEN JUPITER IS NEAR | | OPPOSITION (PREFERABLY BEFORE | | OPPOSITION). | ------------------------------------------------------------------------------------------------------------------------------------ TARGET LIST b)Solar System Targets ID = 5438 [ 6] ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 3 | TARGET NAME: IO-SCAN-E-IN ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: SATELLITE IO ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD = JUPITER | STD = IO | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | OLG OF IO BETWEEN 60 120, CML OF | JUPITER FROM EARTH BETWEEN 147 337, | OLG OF JUPITER BETWEEN 330 30, | SEP OF EUROPA IO FROM EARTH GT 10", | SEP OF GANYMEDE IO FROM EARTH GT 10", | SEP OF CALLISTO IO FROM EARTH GT 10" | ------------------------------------------------------------------------------------------------------------------------------------ REF | DATA | COMMENTS | | 1 |SURF(V) = 5.0 +/- 0.5 | OBSERVE IO WITHIN +/- 30 DEGREES OF 2 |SIZE = 1.0 +/- .2 | EAST ELONGATION, WHEN INSIDE THE 3 |F-LINE(1304)=2.1 +/- 1E-13 | TORUS DENSE REGION AROUND LONGITUDE 4 |W-LINE(1304)=0.01 | 292, AND WHEN JUPITER IS NEAR | | OPPOSITION (PREFERABLY BEFORE | | OPPOSITION). | ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 4 | TARGET NAME: IO-SO2-W ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: SATELLITE IO ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD = JUPITER | STD = IO | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | OLG OF IO BETWEEN 240 300, | OLG OF JUPITER BETWEEN 330 30 | SEP OF EUROPA IO FROM EARTH GT 10", | SEP OF GANYMEDE IO FROM EARTH GT 10", | SEP OF CALLISTO IO FROM EARTH GT 10" | ------------------------------------------------------------------------------------------------------------------------------------ REF | DATA | COMMENTS | | 1 |SURF(V) = 5.0 +/- 0.5 | OBSERVE IO WITHIN +/- 30 DEGREES OF 2 |SIZE = 1.0 +/- .2 | WEST ELONGATION, WHEN JUPITER IS 3 |SURF-CONT(2700) = 2 +/- 1 E-13 | NEAR OPPOSITION (PREFERABLY BEFORE 4 |SURF-CONT(1900) = 1.5 +/- 1 E-15 | OPPOSITION). | ------------------------------------------------------------------------------------------------------------------------------------ TARGET LIST b)Solar System Targets ID = 5438 [ 7] ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 5 | TARGET NAME: IO-SO2-E ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: SATELLITE IO ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD = JUPITER | STD = IO | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | OLG OF IO BETWEEN 60 120, | OLG OF JUPITER BETWEEN 330 30 | SEP OF EUROPA IO FROM EARTH GT 10", | SEP OF GANYMEDE IO FROM EARTH GT 10", | SEP OF CALLISTO IO FROM EARTH GT 10" | ------------------------------------------------------------------------------------------------------------------------------------ REF | DATA | COMMENTS | | 1 |SURF(V) = 5.0 +/- 0.5 | OBSERVE IO WITHIN +/- 30 DEGREES OF 2 |SIZE = 1.0 +/- .2 | EAST ELONGATION, WHEN JUPITER IS 3 |SURF-CONT(2700) = 2 +/- 1 E-13 | NEAR OPPOSITION (PREFERABLY BEFORE 4 |SURF-CONT(1900) = 1.5 +/- 1 E-15 | OPPOSITION). | ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 5438 [ 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 ------------------------------------------------------------------------------------------------------------------------------------ 1.1 DEFINE # FOS/BL IMAGE 4.3 G270H Y-SIZE=5 1 300 S 3 1 SEQ 1.1-1.3 NOGAP SO2OBS Y-SPACE=128 INT ACQ FOR 1.2 COMB=YES CYCLE 4 / 1.1-1.3 SUB-STEP=4 Comments: IO INTERACTIVE ACQUISITION IN 4.3 ARC SEC APERTURE: SET OF 5 SPECTRA AT DIFFERENT Y- DEFLECTIONS TO DETERMINE CENTERING IN X AND Y, THEN UPLINK HST POINTING CORRECTION INFORMATION. REQUIRES REAL- TIME. ------------------------------------------------------------------------------------------------------------------------------------ 1.2 DEFINE # FOS/BL ACCUM 4.3 G190H STEP- 1 52M 80 4 1 SO2OBS PATT=SINGLE 52M Comments: G190H SPECTRA OF IO'S DISK IN. 4.3 ARC SEC APERTURE. ------------------------------------------------------------------------------------------------------------------------------------ 1.3 DEFINE # FOS/BL IMAGE 4.3 G270H STEP-TIME=1.0 1 240 S 3 2 SO2OBS SUB-STEP=1 Y-SIZE=4 Y-SPACE=64 COMB=YES Comments: IMAGE OF IO IN 4.3 APER. FOR POST-OBS POINTING INFORMATION. ------------------------------------------------------------------------------------------------------------------------------------ 2.1 DEFINE # HRS ACQ 2.0 MIRROR-N2 SEARCH-SIZE=5 1 10S 3 1 ONBOARD ACQ FOR SCAN2 2.4 SEQ 2.1-2.4 NO GAP CYCLE 4 / 2.1 - 2.4 Comments: ONBOARD ACQ OF IO WITH N2. PLEASE USE INFORMATION FROM EARLIER IO ACQ'S FOR STEP-TIME: ESTIMATED STEP-TIME = 0.4. ------------------------------------------------------------------------------------------------------------------------------------ 2.2 DEFINE # HRS RAPID 2.0 G140L SAMPLE-TIME=10 1 10 M 8 3 1 SPATIAL SCAN SCAN2 1M 4 SINGLE-EXP CYCLE 4 DARK TIME Comments: SPATIAL SCAN NORTH/SOUTH ACROSS IO DISK AND EXTENDED CORONA +/- 2.5 ARC SEC FROM DISK CENTER. THIS N/S SCAN SHOULD BE SEQUENTIAL (NO GAP) TO THE E/W SCAN OF THE SAME TARGET. ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 5438 [ 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 ------------------------------------------------------------------------------------------------------------------------------------ 2.3 DEFINE # HRS RAPID 2.0 G140L SAMPLE-TIME=10 1 26M 8 3 1 SPATIAL SCAN SCAN2 1M 4 SINGLE-EXP DARK TIME Comments: SPATIAL SCAN EAST/WEST ACROSS IO DISK AND EXTENDED CORONA +/- 2.5 ARC SEC FROM DISK CENTER. ------------------------------------------------------------------------------------------------------------------------------------ 2.4 DEFINE # HRS IMAGE 2.0 MIRROR-N2 1 96.8S 3 1 SCAN2 Comments: IMAGE OF IO IN LSA AFTER CENTERING. ESTIMATED COUNTS/ DWELL POINT FROM IO DISK = 100. ------------------------------------------------------------------------------------------------------------------------------------ 10 USE IO-SO2-W GROUP 10-40 WITHIN SO2OBS 212H Comments: G190H SPECTRA OF IO'S TRAILING HEMISPHERE. TAKE CLOSE IN TIME TO LINENUM 11. ------------------------------------------------------------------------------------------------------------------------------------ 11 USE IO-SO2-E SO2OBS Comments: G190H SPECTRA OF IO'S LEADING HEMISPHERE. TAKE CLOSE IN TIME TO LINEMUM 10, PREFERABLY SEPARATED BY THE MINIMUM OF ~ 21 HOURS. ------------------------------------------------------------------------------------------------------------------------------------ 20 USE IO-SCAN-W- SCAN2 IN Comments: SPATIAL SCAN NORTH/SOUTH AND EAST/WEST OF IO'S DISK/CORONA + /-2.5 ARCSEC FROM CENTER WITH IO NEAR WEST ELONG. AND INSIDE TORUS DENSE REGION NEAR LONGITUDE 292 (OR 112 - MUST BE SAME AS LINE 40.00) ------------------------------------------------------------------------------------------------------------------------------------ 30 USE IO-SCAN-W- SCAN2 OUT Comments: SPATIAL SCAN NORTH/SOUTH AND EAST/WEST OF IO'S DISK/CORONA + /-2.5 ARCSEC FROM CENTER, WITH IO NEAR WEST ELONG. AND OUTSIDE TORUS DENSE REGION NEAR LONGITUDE 22 (OR 202) ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 5438 [ 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 ------------------------------------------------------------------------------------------------------------------------------------ 40 USE IO-SCAN-E- SCAN2 IN Comments: SPATIAL SCAN NORTH/SOUTH AND EAST/WEST OF IO'S DISK/CORONA + /-2.5 ARCSEC FROM CENTER, WITH IO NEAR EAST ELONG. AND INSIDE TORUS DENSE REGION NEAR LONGITUDE 292 (OR 112 - MUST BE SAME AS LINE 20.0) ------------------------------------------------------------------------------------------------------------------------------------ Scan Paramters Form Proposal ID: 5438 [ 11] ------------------------------------------------------------------------------------------------------------------------------------ Data ID: 1 Exposure Logsheet lines: 2.2 FGS Scan: CONTINUOUS Dwell Only: dwell points/line: 0 Seconds per dwell: 0.00 Scan width (arc-secs): 0.0000 Scan length (arc-secs): 5.0000 Angle between sides (degrees) 90.00 Number of lines: 1 Scan rate (arc-sec/sec): 0.0083 PA of first scan line (degrees) 20.000 Scan frame (CEL or S/C): CEL Length Offset (arc-sec): 2.5000 Width Offset (arc-sec): 0.0000 ------------------------------------------------------------------------------------------------------------------------------------ Data ID: 2 Exposure Logsheet lines: 2.3 FGS Scan: CONTINUOUS Dwell Only: dwell points/line: 0 Seconds per dwell: 0.00 Scan width (arc-secs): 0.0000 Scan length (arc-secs): 5.0000 Angle between sides (degrees) 90.00 Number of lines: 1 Scan rate (arc-sec/sec): 0.0032 PA of first scan line (degrees) 110.000 Scan frame (CEL or S/C): CEL Length Offset (arc-sec): 2.5000 Width Offset (arc-sec): 0.0000 ------------------------------------------------------------------------------------------------------------------------------------ Summary Form for Proposal 5438 [ 12] Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations FOS/BL HRS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ACCUM ACQ RAPID ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters Y-SIZE Y-SPACE COMB SUB-STEP STEP-PATT=SINGLE STEP-TIME=1.0 SUB-STEP=1 Y-SIZE=4 Y-SPACE=64 COMB=YES SEARCH-SIZE=5 SAMPLE-TIME=10 ------------------------------------------------------------------------------------------------------------------------------------ Proposal for GO ------------------------------------------------------------------------------------------------------------------------------------ S/C Hours 9.03 ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category SOLAR SYSTEM ------------------------------------------------------------------------------------------------------------------------------------ Scientific Sub-category SATELLITES ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements SEQ 1.1-1.3 NOGAP; INT ACQ FOR 1.2; CYCLE 4 / 1.1-1.3 ONBOARD ACQ FOR 2.4; SEQ 2.1-2.4 NO GAP; CYCLE 4 / 2.1 - 2.4 SPATIAL SCAN SINGLE-EXP; CYCLE 4; DARK TIME; GROUP 10-40 WITHIN 212H; ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements G270H G190H MIRROR-N2 G140L ------------------------------------------------------------------------------------------------------------------------------------ Target Names IO-SCAN-W-IN IO-SCAN-W-OUT IO-SCAN-E-IN IO-SO2-W IO-SO2-E ------------------------------------------------------------------------------------------------------------------------------------