Page 1 PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID 4600c Report Date: 09-May-96:19:44 Version: ********** Check-in Date: ********** 1.Proposal Title: FUV SPECTROSCOPY OF IO'S SO2 ATMOSPHERE AND SURFACE -- CYCLE 3 HIGH ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Proposal Type 5. Continuation ID SOLAR SYSTEM GO Sub Category ------------------------------------------------------------------------------------ 6. Principal Investigator Institution Country Telephone Dr. John T. Clarke UNIVERSITY OF MICHIGAN USA 313-747-3540 ------------------------------------------------------------------------------------ 7. Abstract Cycle 1 HST observations of Io have provided new insights into the nature of Io's surface albedo, the distribution of the SO2 atmosphere, and the extent and excitation of the FUV airglow emissions. FOC images show an anti-correlation between the brightness at 4000 A and 2800 A, due to either surface SO2 frost or SO2 gas absorption above the frost at the shorter wavelength. FOS spectra of the albedo spectrum at high signal to noise clearly show SO2 gas absorption bands near 1900- 2000 A and evidence up to 1000 times spatial variation in the SO2 gas column from the 2300 A spectrum. The FOS and GHRS airglow spectra have for the first time resolved the extent of the FUV emission lines (1.7 Io radii in diameter), and found that these lines decrease by a factor of 4-5 within 15 minutes of Io's passing into eclipse. This suggests that in shadow either the SO2 atmosphere condenses onto the surface or the ionosphere recombines rapidly: the difference between these two possibilities is very significant. In cycle 3 we propose to scan across Io with a small FOS aperture to obtain spatially resolved spectra of the known bright and dark regions to discriminate between gas absorption and surface albedo changes. We will also obtain FUV spectra of Io emerging from eclipse to determine the time scale on which the FUV airglow emission lines recover their intensity on return into sunlight. ------------------------------------------------------------------------------------ 8. Scientific Key Words: PLANETARY SATELLITE, PLASMA TORUS ------------------------------------------------------------------------------------ 9. Est obs time (hours) pri: 7.75 par: 0 10. Num targs pri: 1 par: 0 ------------------------------------------------------------------------------------ 11. Instruments requested: FOS ------------------------------------------------------------------------------------ 12. Special sched req: Time Critical obs. ------------------------------------------------------------------------------------ Page 2 I. GENERAL FORM Proposal 4600c PI: Dr. John T. Clarke Proposal Title: FUV SPECTROSCOPY OF IO'S SO2 ATMOSPHERE AND SURFACE -- CYCLE 3 HIGH ------------------------------------------------------------------------------------ 1. Proposers: Proposers Institution Country ESA ------------------------------------------------------------------------------------ Pi John T. Clarke 2660 USA Melissa Mcgrath 3470 USA Joe Ajello 2370 USA Nick Schneider 1760 USA Gilda Ballester 2660 USA ------------------------------------------------------------------------------------ 2. Scientific Justification. ------------------------------------------------------------------------------------ 3. Description of proposed observations. We propose to obtain spectra of specific regions on Io with FOS G190H and G270H using the 0.25 arc sec aperture with offsets from the acquired center of Io. These will be obtained near times of Io western elongation, when the apparent motion is small and corresponding to the existing FOC images at 2800 A. We will center the aperture on known bright and dark regions from the FOC images, and also perform a single spatial scan N/S across the disk of Io to look for unexpected spectral changes. We will also take a FOS G130H spectral time series of Io emerging from eclipse behind Jupiter, with Io centered in the 4.3 arc sec aperture: this will complete the series of eclipse observations begun in cycles 1 and 2. ------------------------------------------------------------------------------------ 4. Justification of need for HST observations. The line emissions excited by the impact of magnetospheric plasma at Io are radiated chiefly in the FUV, and require a space-based instrument with high sensitivity and angular resolution to be detected. Ground-based instruments today have great difficulty in detecting atmospheric line emissions from Io. Emissions from the extended atmosphere of Io are just detectable with the IUE, but higher sensitivity and angular resolution are required to determine the source region and spatial distribution. Only the HST is fast enough to detect changes in emission brightness through the eclipse events. The capability of the FOS for measuring the 1600-3300 A albedo of Io has been demonstrated in cycle 1 in 2 separate programs, whereas IUE spectra are much too noisy below roughly 2400 A due to the decreasing flux. Even with the HST spherical aberration, the central 0.15 arc sec peak is sufficient to sample regions on the 1 arc sec Io disk with the 0.25 arc sec aperture and compare the spectra of different regions of known overall reflectivity from the FOC images. Only the angular resolution and large aperture of HST can provide the high signal spatially resolved spectra proposed here. After the insertion of COSTAR the point spread function should be greatly improved, however there will be a loss of sensitivity at the shorter wavelengths from the added mirrors. We prefer to do what we can now in the UV, and after COSTAR we may propose additional observations at longer wavelengths. ------------------------------------------------------------------------------------ 5. Description of special scheduling requirements. The FOS G190H and G270H spectra are to be scheduled near western elongation of Io. Io must be acquired and its center determined to within roughly 0.10 arc sec: an offset will then be made to position the FOS 0.25 arc sec aperture on the desired region(s) of Io. The FOS G130H observation of Io must be centered (+/- 15 min.) on the time of eclipse re-appearance, and must occur at the time of year when the orbital longitude of Jupiter is 250 to 300 degrees. These constraints can be relaxed somewhat if necessary to allow scheduling. Page 3 ------------------------------------------------------------------------------------ 6. Description of special calibration exposures. None. ------------------------------------------------------------------------------------ 7. Data reduction and analysis plans. The UV spectra of Io will be reduced using standard routines as in cycle 1: both JC and MM have reduced their cycle 1 data using IDL on Sun workstations, and both have complete software packages for the reduction and analysis of HST data. We have developed a synthetic model program in IDL which predicts the albedo spectrum of Io for assumed surface amounts of SO2 frost and a given column of SO2 gas (see section 2). We are presently adapting the Ballester et al (1990) IUE models for our cycle 1 HST FOS spectra which accounts in more detail for spatial surface and atmospheric structure. We are also in the process of a quantitative model of the grating scatter in FOS for the 3 high dispersion gratings: we expect these results to be concluded within the next 6 months. In other words, we are ready to reduce, model, and interpret the new albedo data. J. Ajello and collaborators are performing laboratory studies of electron excitation of SO2 gas, measuring the electron impact induced fluorescence spectrum of SO2 in the UV (400-2000 A) at 2.5 A resolution. For the strongest features we have measured excitation functions from 0-400 eV for modeling the excitation rates at Io. This group also has a proposal in to measure the SO2 gas photoabsorption cross sections over 1600-3300 A as a function of pressure and temperature to address outstanding questions about line saturation effects in the low density/low temperature lower atmosphere of Io. ------------------------------------------------------------------------------------ 8. Additional comments or special requests. None. ------------------------------------------------------------------------------------ 9. Description of previous HST work. 1. GO 2602 - "The Excitation of the Atmospheres of Planetary Satellites", J. Clarke PI, J. Ajello and N. Schneider Co-I's - directly related. 2. GO 2603 - "Parallel Observations of H Ly alpha Emission from the Local ISM", J. Clarke PI - unrelated. 3. GO 2393 - "D/H Ratio of Venus and Mars from Lyman alpha Emission", J. Clarke Co-I - unrelated. 4. GO 2625 - "Excitation Processes for the Outer Planet UV Emissions", M. McGrath and J. Clarke Co-I's - unrelated. 5. GO 2627 - "Io's Atmosphere and its Interaction with the Plasma Torus", Co-I's: M. McGrath, G. Ballester - directly related. 6. GO 3511 - "H Ly alpha Dayglow Emission Line Profiles from the Outer Planets", J. Clarke PI - unrelated. 7. GO 3616 - "Upper Atmospheres of Uranus and Neptune", M. McGrath PI, J. Clarke Co-I - unrelated. 8. GO 3617 - "The UV Emissions of Titan", M. McGrath PI, unrelated. 9. GO 3618 - "Excitation Processes for the Outer Planet UV Emissions" - Cycle 2 Continuation - M. McGrath PI - unrelated. 10. GO 3862 - "The Excitation of the Atmospheres of Planetary Satellites", J. Clarke PI, - J. Ajello and N. Schneider Co-I's - directly related. ------------------------------------------------------------------------------------ 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 and 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 Page 4 Name: JOHN T. CLARKE Category: PI Institution: UNIVERSITY OF MICHIGAN Address: AOSS DEPT. City: ANN ARBOR State: MI Zip Code: 481092143 Country: USA Telephone: Telex (or e-mail): ------------------------------------------------------------------------------------ TARGET LIST b)Solar System Targets ID = 4600c [ 5] ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 1 | TARGET NAME: IO-ACQ-SPOTS ------------------------------------------------------------------------------------------------------------------------------------ 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 215-235, | OLG OF JUPITER BETWEEN 300 60 | ------------------------------------------------------------------------------------------------------------------------------------ REF | DATA | COMMENTS | | 1 |SURF(V) = 5.0 +/- 0.5 | IO ACQUISITION IN 4.3 ARC SEC 2 |SIZE = 1.0 +/- .2 | APERTURE: TAKE A SET OF 11 SPECTRA 3 |SURF-CONT(2700) = 2 +/- 1 E-13 | AT DIFFERENT Y-DEFLECTIONS TO | | DETERMINE CENTERING IN X AND Y (FROM | | OBSERVED WAVELENGTH) THEN UPLINK HST | | POINTING CORRECTION. | ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 2 | TARGET NAME: IO-W-BRIGHT ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: SATELLITE IO ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD = JUPITER | STD = IO | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | TYPE = CARTO, | SEP OF EUROPA IO FROM EARTH GT 10", LONG = 222.0, | SEP OF GANYMEDE IO FROM EARTH GT 10", LAT = +5.0 | SEP OF CALLISTO IO FROM EARTH GT 10", | OLG OF IO BETWEEN 230 265, | OLG OF JUPITER BETWEEN 300 60 | ------------------------------------------------------------------------------------------------------------------------------------ REF | DATA | COMMENTS | | 1 |SURF(V) = 5.0 +/- 0.5 | OBSERVE BRIGHT REGION ON IO WHEN IO 2 |SIZE = 1.0 +/- .2 | IS FROM ABOUT -30 TO -5 DEGREES FROM 3 |SURF-CONT(2700) = 2 +/- 1 E-13 | WESTERN ELONGATION, WHEN JUPITER IS 4 |SURF-CONT(1900) = 1.5 +/- 1 E-15 | WITHIN 60 DEGREES OF OPPOSITION. | | PLEASE NOTE THAT THE WINDOWS CAN BE | | EXPANDED IF NEEDED TO SCHEDULE. | ------------------------------------------------------------------------------------------------------------------------------------ TARGET LIST b)Solar System Targets ID = 4600c [ 6] ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 3 | TARGET NAME: IO-W-PELE ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: SATELLITE IO ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD = JUPITER | STD = IO | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | TYPE = CARTO, | SEP OF EUROPA IO FROM EARTH GT 10", LONG = 257.0, | SEP OF GANYMEDE IO FROM EARTH GT 10", LAT = -19.0 | SEP OF CALLISTO IO FROM EARTH GT 10", | OLG OF IO BETWEEN 240 280, | OLG OF JUPITER BETWEEN 300 60 | ------------------------------------------------------------------------------------------------------------------------------------ REF | DATA | COMMENTS | | 1 |SURF(V) = 5.0 +/- 0.5 | OBSERVE PELE VOLCANO ON IO WHEN IO 2 |SIZE = 1.0 +/- .2 | IS FROM ABOUT -30 TO +10 DEGREES 3 |SURF-CONT(2700) = 2 +/- 1 E-13 | FROM WESTERN ELONGATION, WHEN 4 |SURF-CONT(1900) = 1.5 +/- 1 E-15 | JUPITER IS WITHIN 60 DEGREES OF | | OPPOSITION. PLEASE NOTE THAT THE | | WINDOWS CAN BE EXPANDED IF NEEDED TO | | SCHEDULE. | ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 4 | TARGET NAME: IO-W-DARK ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: SATELLITE IO ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD = JUPITER | STD = IO | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | TYPE = CARTO, | SEP OF EUROPA IO FROM EARTH GT 10", LONG = 288.0, | SEP OF GANYMEDE IO FROM EARTH GT 10", LAT = -15.0 | SEP OF CALLISTO IO FROM EARTH GT 10", | OLG OF IO BETWEEN 265 295, | OLG OF JUPITER BETWEEN 300 60 | ------------------------------------------------------------------------------------------------------------------------------------ REF | DATA | COMMENTS | | 1 |SURF(V) = 5.0 +/- 0.5 | OBSERVE DARK REGION ON IO WHEN IO IS 2 |SIZE = 1.0 +/- .2 | FROM ABOUT -5 TO +25 DEGREES FROM 3 |SURF-CONT(2700) = 2 +/- 1 E-13 | WESTERN ELONGATION, WHEN JUPITER IS 4 |SURF-CONT(1900) = 1.5 +/- 1 E-15 | WITHIN 60 DEGREES OF OPPOSITION. | | PLEASE NOTE THAT THE WINDOWS CAN BE | | EXPANDED IF NEEDED TO SCHEDULE. | ------------------------------------------------------------------------------------------------------------------------------------ TARGET LIST b)Solar System Targets ID = 4600c [ 7] ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 5 | TARGET NAME: IO-W-LOKI ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: SATELLITE IO ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD = JUPITER | STD = IO | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | TYPE = CARTO, | SEP OF EUROPA IO FROM EARTH GT 10", LONG = 304.0, | SEP OF GANYMEDE IO FROM EARTH GT 10", LAT = +20.0 | SEP OF CALLISTO IO FROM EARTH GT 10", | OLG OF IO BETWEEN 280 325, | OLG OF JUPITER BETWEEN 300 60 | ------------------------------------------------------------------------------------------------------------------------------------ REF | DATA | COMMENTS | | 1 |SURF(V) = 5.0 +/- 0.5 | OBSERVE LOKI VOLCANO ON IO WHEN IO 2 |SIZE = 1.0 +/- .2 | IS FROM ABOUT +10 TO +55 DEGREES 3 |SURF-CONT(2700) = 2 +/- 1 E-13 | FROM WESTERN ELONGATION, WHEN 4 |SURF-CONT(1900) = 1.5 +/- 1 E-15 | JUPITER IS WITHIN 60 DEGREES OF | | OPPOSITION. PLEASE NOTE THAT THE | | WINDOWS CAN BE EXPANDED IF NEEDED TO | | SCHEDULE. | ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 6 | TARGET NAME: IO-ACQ-SCAN ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: SATELLITE IO ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD = JUPITER | STD = IO | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | ------------------------------------------------------------------------------------------------------------------------------------ REF | DATA | COMMENTS | | 1 |SURF(V) = 5.0 +/- 0.5 | IO ACQUISITION IN 4.3 ARC SEC 2 |SIZE = 1.0 +/- .2 | APERTURE: TAKE A SET OF 5 SPECTRA AT 3 |SURF-CONT(2700) = 2 +/- 1 E-13 | DIFFERENT Y-DEFLECTIONS TO DETERMINE | | CENTERING IN X AND Y (FROM OBSERVED | | WAVELENGTH) THEN UPLINK HST POINTING | | CORRECTION. | ------------------------------------------------------------------------------------------------------------------------------------ TARGET LIST b)Solar System Targets ID = 4600c [ 8] ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 7 | TARGET NAME: IO-W-SCAN ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: SATELLITE IO ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD = JUPITER | STD = IO | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | SEP OF EUROPA IO FROM EARTH GT 10", | SEP OF GANYMEDE IO FROM EARTH GT 10", | SEP OF CALLISTO IO FROM EARTH GT 10", | OLG OF IO BETWEEN 250 290, | OLG OF JUPITER BETWEEN 300 60 | ------------------------------------------------------------------------------------------------------------------------------------ REF | DATA | COMMENTS | | 1 |SURF(V) = 5.0 +/- 0.5 | OBSERVE IO WITHIN +/- 20 DEGREES OF 2 |SIZE = 1.0 +/- .2 | WESTERN ELONGATION WHEN JUPITER IS 3 |SURF-CONT(2700) = 2 +/- 1 E-13 | WITHIN 60 DEGREES OF OPPOSITION. 4 |SURF-CONT(1900) = 1.5 +/- 1 E-15 | PLEASE NOTE THAT THE WINDOWS CAN BE | | EXPANDED IF NEEDED TO SCHEDULE. | ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 8 | TARGET NAME: IO-ACQ-SHADOW ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: OFFSET EUROPA ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD = JUPITER | STD = EUROPA | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | ------------------------------------------------------------------------------------------------------------------------------------ REF | DATA | COMMENTS | | 1 |SURF(V) = 5.3 +/- 0.5 | STRATEGY IS TO ACQUIRE EUROPA AND 2 |SIZE = 0.9 +/- .2 | THEN BLIND OFFSET TO IO, BOTH IN 4.3 3 |SURF-CONT(2700) = 2 +/- 1 E-13 | APERTURE. TO ACQUIRE EUROPA WITH | | FOS, TAKE A SET OF 5 SPECTRA AT | | DIFFERENT Y-DEFLECTIONS TO DETERMINE | | CENTERING IN X AND Y (FROM OBSERVED | | WAVELENGTH) THEN UPLINK HST POINTING | | CORRECTION. | ------------------------------------------------------------------------------------------------------------------------------------ TARGET LIST b)Solar System Targets ID = 4600c [ 9] ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 9 | TARGET NAME: IO-EGRESS ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: SATELLITE IO ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD = JUPITER | STD = IO | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | OLG OF JUPITER BETWEEN 250 300, | ECL U OF IO BY JUPITER, | SEP OF EUROPA IO FROM EARTH GT 10", | SEP OF GANYMEDE IO FROM EARTH GT 10", | SEP OF CALLISTO IO FROM EARTH GT 10", | SEP OF EUROPA IO FROM EARTH LT 2' | ------------------------------------------------------------------------------------------------------------------------------------ REF | DATA | COMMENTS | | 1 |SURF(V) = 5.0 +/- 0.5 | OBSERVE IO COMING OUT OF ECLIPSE 2 |SIZE = 1.0 +/- .2 | BEHIND JUPITER; BEGIN FOS EXPOSURE 3 |SURF-CONT(2700) = 2 +/- 1 E-13 | 15-20 MINUTES BEFORE IO ECLIPSE | | REAPPEARANCE AND SCHEDULE WHEN | | ORBITAL LONGITUDE OF JUPITER IS 250 | | TO 300 DEGREES. PLEASE NOTE THAT THE | | WINDOWS CAN BE EXPANDED IF NEEDED TO | | SCHEDULE. | ------------------------------------------------------------------------------------------------------------------------------------ TARGET NUMBER: 10 | TARGET NAME: IO-ACQ-IMAGE ------------------------------------------------------------------------------------------------------------------------------------ TARGET DESCRIPTION: SATELLITE IO ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 1 | TARGET POSITION LEVEL 2 | STD = JUPITER | STD = IO | ------------------------------------------------------------------------------------------------------------------------------------ TARGET POSITION LEVEL 3 | WINDOWS | | ------------------------------------------------------------------------------------------------------------------------------------ REF | DATA | COMMENTS | | 1 |SURF(V) = 5.0 +/- 0.5 | ACQUISITION IMAGE OF IO IN 4.3 FOS 2 |SIZE = 1.0 +/- .2 | APERTURE FOR POST-UPLINK POINTING 3 |SURF-CONT(2700) = 2 +/- 1 E-13 | INFORMATION. | ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 4600c [ 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 IO-ACQ- FOS/BL IMAGE 4.3 G270H Y-SIZE=5 1 660 S 3 1 CYCLE 3 / 1-16 SPOTS Y-SPACE=64 SEQ 1-10 NOGAP COMB=YES INT ACQ FOR 2 SUB-STEP=4 Comments: SPECTRA OF IO FOR INTERACTIVE ACQUISITION: REQUIRES REAL-TIME UPLINK FOR S/C MOTIONS IN X AND Y DURING EARTH OCCULTATION. ------------------------------------------------------------------------------------------------------------------------------------ 2 IO-ACQ- FOS/BL IMAGE 4.3 G270H STEP-TIME=1.0 1 4.0 S 3 2 SPOTS SUB-STEP=1 Y-SIZE=4 Y-SPACE=64 COMB=NO Comments: IMAGE OF 4.3 APERTURE FOR POST- UPLINK POINTING INFORMATION. NEXT, OFFSET TO 0.3 APERTURE FOR SPECTRA IN LINENUM 3. ------------------------------------------------------------------------------------------------------------------------------------ 3 IO-W-BRIGHT FOS/BL RAPID 0.3 G270H STEP- 1 9 M 3 1 PATT=SINGLE READ-TIME=60 Comments: G270H SPECTRA OF BRIGHT SPOT OF IO AT LONG,LAT = 222,+5. ------------------------------------------------------------------------------------------------------------------------------------ 4 IO-W-BRIGHT FOS/BL RAPID 0.3 G190H STEP- 1 33 M 4 1 PATT=SINGLE READ-TIME=60 Comments: G190H SPECTRA OF BRIGHT SPOT OF IO AT LONG,LAT = 222,+5. ------------------------------------------------------------------------------------------------------------------------------------ 5 IO-W-PELE FOS/BL RAPID 0.3 G270H STEP- 1 10 M 3 1 PATT=SINGLE READ-TIME=60 Comments: G270H SPECTRA OF PELE VOLCANO OF IO AT LONG,LAT = 257,-19. ------------------------------------------------------------------------------------------------------------------------------------ 6 IO-W-PELE FOS/BL RAPID 0.3 G190H STEP- 1 31 M 4 1 PATT=SINGLE READ-TIME=60 Comments: G270H SPECTRA OF PELE VOLCANO OF IO AT LONG,LAT = 257,-19. ------------------------------------------------------------------------------------------------------------------------------------ 7 IO-W-DARK FOS/BL RAPID 0.3 G270H STEP- 1 10 M 3 1 PATT=SINGLE READ-TIME=60 Comments: G270H SPECTRA OF DARK SPOT OF IO AT LONG,LAT = 288,-15. ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 4600c [ 11] ------------------------------------------------------------------------------------------------------------------------------------ 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 IO-W-DARK FOS/BL RAPID 0.3 G190H STEP- 1 38 M 4 1 PATT=SINGLE READ-TIME=60 Comments: G270H SPECTRA OF DARK SPOT OF IO AT LONG,LAT = 288,-15. ------------------------------------------------------------------------------------------------------------------------------------ 9 IO-W-LOKI FOS/BL RAPID 0.3 G270H STEP- 1 10 M 3 1 PATT=SINGLE READ-TIME=60 Comments: G270H SPECTRA OF LOKI VOLCANO OF IO AT LONG,LAT = 304,+20. ------------------------------------------------------------------------------------------------------------------------------------ 10 IO-W-LOKI FOS/BL RAPID 0.3 G190H STEP- 1 31 M 4 1 PATT=SINGLE READ-TIME=60 Comments: G270H SPECTRA OF LOKI VOLCANO OF IO AT LONG,LAT = 304,+20. ------------------------------------------------------------------------------------------------------------------------------------ 11 IO-ACQ-SCAN FOS/BL IMAGE 4.3 G270H Y-SIZE=5 1 300 S 3 1 SEQ 11-13 NOGAP Y-SPACE=128 INT ACQ FOR 12 COMB=YES SUB-STEP=4 Comments: SPECTRA OF IO FOR INTERACTIVE ACQUISITION: REQUIRES REAL-TIME UPLINK FOR S/C MOTIONS IN X AND Y DURING EARTH OCCULTATION. NEXT, OFFSET TO 0.3 APERTURE FOR SPECTRA IN LINENUM 12. ------------------------------------------------------------------------------------------------------------------------------------ 12 IO-W-SCAN FOS/BL RAPID 0.3 G270H STEP- 1 24 M 3 1 SPATIAL SCAN PATT=SINGLE REQ UPLINK COMB=YES READ-TIME=60.0 Comments: VERY SLOW SPATIAL SCAN N/S ACROSS DISK OF IO. REQUIRES REVIEW BY STSCI. ------------------------------------------------------------------------------------------------------------------------------------ 13 IO-ACQ- FOS/BL IMAGE 4.3 G270H STEP-TIME=1.0 1 4.0 S 3 2 IMAGE SUB-STEP=1 Y-SIZE=4 Y-SPACE=64 COMB=NO Comments: IMAGE OF 4.3 APERTURE FOR POST- UPLINK POINTING INFORMATION. ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 4600c [ 12] ------------------------------------------------------------------------------------------------------------------------------------ 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 ------------------------------------------------------------------------------------------------------------------------------------ 14 IO-ACQ- FOS/BL IMAGE 4.3 G270H Y-SIZE=5 1 300 S 3 1 SEQ 14-16 NOGAP SHADOW Y-SPACE=128 INT ACQ FOR 15 COMB=YES SUB-STEP=4 Comments: SPECTRA OF EUROPA FOR INT. ACQ. REQUIRES REAL-TIME UPLINK FOR S /C MOTIONS IN X AND Y DURING EARTH OCCULTATION. AFTER CENTERING ON EUROPA, OFFSET TO IO, WHICH IS IN SHADOW. ------------------------------------------------------------------------------------------------------------------------------------ 15 IO-EGRESS FOS/BL RAPID 4.3 G130H STEP-PATT=DEF 1 25 M 3 1 DARK TIME READ-TIME=60. REQ UPLINK Comments: G130H SPECTRA OF IO: BEGIN 15- 20 MINUTES BEFORE IO REAPPEARS IN SUNLIGHT FROM ECLIPSE. SCHEDULE IN DARK TIME DUE TO 1304 OXYGEN AIRGLOW. ------------------------------------------------------------------------------------------------------------------------------------ 16 IO-ACQ- FOS/BL IMAGE 4.3 G270H STEP-TIME=1.0 1 4.0 S 3 2 IMAGE SUB-STEP=1 Y-SIZE=4 Y-SPACE=64 COMB=NO Comments: IMAGE OF 4.3 APERTURE FOR POST- UPLINK POINTING INFORMATION, PERFORMED WHEN IO IS IN SUNLIGHT. ------------------------------------------------------------------------------------------------------------------------------------ Scan Paramters Form Proposal ID: 4600c [ 13] ------------------------------------------------------------------------------------------------------------------------------------ Data ID: 1 Exposure Logsheet lines: 12.00 FGS Scan: CONTINUOUS Dwell Only: dwell points/line: 0 Seconds per dwell: 0.00 Scan width (arc-secs): 0.0000 Scan length (arc-secs): 1.2600 Angle between sides (degrees) 90.00 Number of lines: 1 Scan rate (arc-sec/sec): 0.0009 PA of first scan line (degrees) 25.000 Scan frame (CEL or S/C): CEL Length Offset (arc-sec): 0.6300 Width Offset (arc-sec): 0.0000 ------------------------------------------------------------------------------------------------------------------------------------ Summary Form for Proposal 4600c [ 14] Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations FOS/BL ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE RAPID ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters Y-SIZE Y-SPACE COMB SUB-STEP STEP-TIME=1.0 SUB-STEP=1 Y-SIZE=4 Y-SPACE=64 COMB=NO STEP-PATT=SINGLE READ-TIME=60 READ-TIME=60.0 STEP-PATT=DEF READ-TIME=60. ------------------------------------------------------------------------------------------------------------------------------------ Proposal for GO ------------------------------------------------------------------------------------------------------------------------------------ S/C Hours 7.75 ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category SOLAR SYSTEM ------------------------------------------------------------------------------------------------------------------------------------ Scientific Sub-category ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements CYCLE 3 / 1-16; SEQ 1-10 NOGAP; INT ACQ FOR 2; SEQ 11-13 NOGAP; INT ACQ FOR 12; SPATIAL SCAN ; REQ UPLINK; SEQ 14-16 NOGAP; INT ACQ FOR 15; DARK TIME; ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements G270H G190H G130H ------------------------------------------------------------------------------------------------------------------------------------ Target Names IO-ACQ-SPOTS IO-W-BRIGHT IO-W-PELE IO-W-DARK IO-W-LOKI IO-ACQ-SCAN IO-W-SCAN IO-ACQ-SHADOW IO-EGRESS IO-ACQ-IMAGE ------------------------------------------------------------------------------------------------------------------------------------