GALILEO VENUS SCIENCE OBJECTIVES FIRST TIME 1. DARKSIDE IR MAPPING OF FEATURES AND MOTIONS IN AND BELOW CLOUD DECK (NIMS) 2. SMALL SCALE FEATURE TRACK, MIDALTITUDE OR EQUATORIAL (SSI,NIMS) 3. SPECTROSCOPY OF NIDDLE AND DEEP ATMOSPHERE (NIMS) COLLABORATIVE (GLL AND PVO DURING FLYBY) 4. GLOBAL FEATURE TRACKING (SSI, NIMS, UVS, PPR) 5. AURORAL EXCITATION MECHANISM (UVS, MAG,PLS, EPD) 6. IONOSPHERIC MAGNETIZATION/INTERPLANETARY FIELD (MAG) 7. ION PICKUP (MAG,PLS,EPD) 8. BOWSHOCK UPSTREAM PARTICLES AND WAVES (MAG,PLS,EPD,PWS) COLLABORATIVE (GLL AND PREVIOUS S/C) 9. LIMB STUDIES (SSI, NIMS) 10. LIGHTNING (SSI,PWS) 11. CLOUD TOP TEMPERATURES (NIMS, PPR) 12. SPATIAL VARIABILITY OF H20, H2SO4, O/CO, IN AND ABOVE CLOUDS (NIMS, PPR,UVS) 13. PLANETARY ENERGY BUDGET (PPR) 14. UV/VISIBLE NIGHTGLOW DISTRIBUTION (UVS) 20 NIMS VENUS OBSERVATION LOG 11/11/90 K. H. Baines Notes: In the detailed description of each OAPEL (beginning on page 5): Start Time is the groupstart of the TARGET PA Tape Start is the groupstart of the RECORD PA Mosaic End is the groupend of the CSMOSAIC PA Tape End is the groupend of the RECORD PA VCA (Venus Closest Approach) relative times assume 90-041/06:08:49.59 GMT as the absolute closest approach time Start Time for a PA as listed in the PA SEQUENCE is the time by which the PA is guaranteed to be set up and ready to run. Set-up time (e.g., tape recorder runup, target slews) is generally not included. 21 NIMS/VENUS TIMELINE SUMMARY (revised 11/11/90) Observation Oapel Start Times Duration Name Target Setup End Mosaic OAPEL Tape Partial VPDIN1 41/01:48:22 41/02:31:44 44 mins 42 mins Disk Imaging (1 gp, contiguous) Jail Bars VJBARS 41/03:40:22 41/04:02:00 22 mins 20 mins (Longmap, non- contiguous) Partial VPDIN2 41/04:02:08 41/05:03:48 62 mins 60 mins Disk Imaging (1 gp, contiguous) Limbscan VLSN 41/05:31:44 41/05:38:55 7 mins 6 mins Nightside Limbscan VLSD 41/06:07:45 41/06:13:00 5 mins 4 mins Dayside Totals: 140 mins 132 mins KHB 5/30/89 rev 6/7/89 rev 10/4/89 rev 11/11/90 22 NIMS/VENUS OBSERVATION SUMMARY (Revised 11/11/90) OAPEL Spatial Res. NIMS Sub-S/C Territory Slew Overlap (Km/Nimsel) Mode Latitude Covered Rate (nimsels) Start End Start End Lats Longs (urad/sec) VPDIN1 51 49 1 gp 17.9 17.5 90N-90S 280-30W 1500 10 VJBARS 28 24 Longmap 10.2 7.5 3 non-contiguous 0 0 stripes: (~4 inte- (May be ~ 5 W grations/ several ~ 357 W sample) nimsels ~ 339 w between Maxwell Montes samples) sampled VPDIN2 24 13 1 gp 7.2 -9.5 90N-7S 335-15W 1500 10 VLSN 12.3 11.9 Long spec- 1 scan from -20 to 29 N/A trometer -27.7 -32.7 +230 km Near anti-sub- solar point VLSD 10.2 10.4 Long spec- 1 scan from -10 to 55 N/A trometer -52.6 -52.9 +260 km altitude Near sub-solar point KHB 5/30/89 rev 6/7/89 rev 10/4/89 rev 11/11/90 23 NIMS/VENUS TAPE RECORDER ALLOCATION OAPEL Km/Nimsel Tracks Percent of NIMS allocation of 1.01 tracks VPDIN1 51-49 0.32 31.8 VJBARS 26-22 0.15 15.2 VPDIN2 22-11 0.46 45.5 VLSN 12 0.05 4.5 VLSD 10 0.03 3.0 Totals: 1.01 100.00 68.2% of NIMS tape used to acquire spatial resolutions better than 28 km 100% of NIMS tape used to acquire spatial resolutions better than 51 km => 100% of NIMS tape applicable to small-scale cloud structure 22.7% of NIMS tape used to acquire high-spectral resolution data (either longmap or long spectrometer modes) => 22.7% of NIMS tape applicable to atmospheric composition 77.3% of NIMS tape used to acquire contiguous maps => 77.3% of NIMS tape applicable to dynamics KHB 5/30/89 rev 11/11/90 24 OAPEL NAME: VPDIN1 Start Time: 90-41/01:48:22.266 (VCA - 04:20:27.32) Tape Start: 90-41/01:49:54.933 Mosaic End: 90-41/02:31:26 Tape End : 90-41/02:31:43.600 (VCA - 03:37:05.99) APPROXIMATE START GEOMETRY: Sub-spacecraft Latitude: 14.0 N Sub-spacecraft Longitude: 349.1 W Phase angle: 148.4 NIMS INSTRUMENT MODE: Fixed Grating, grating position 16 NIMS GAIN STATE: 2 ("Nominal" sensitivity) AVERAGE NIMS SPATIAL RESOLUTION: 50 km OBJECTIVE: Obtain high spatial resolution multi-spectral imagery at twice the spatial resolution available from Earth in order to examine small-scale deep-atmosphere cloud properties from pole to pole. In particular, study convective, zonal, and meridional transport processes in conjunction with VPDIN2 observations. Quantify the lower-atmosphere wave structure and wind fields, examining in particular orographic effects of mountainous terrain such as Ishtar Terra and Maxwell Montes. DESIGN: General design: Fixed grating (1 grating position) Contiguous sampling (1500 microrads/sec slewrate) 10 pixel overlap between swaths Details: Spacecraft distance at -04:00 is 97083 km to cloudtops => 15.8 Venus-radii, with 6140 km being a Venus cloudtop radius. 253 nimsels span the disk. Spatial resolution is ~ 50 km. PA SEQUENCE: PA Start Time PA ID Comments SCITLM 90-041/01:48:10.264 176IB EHRMPW TARGET 01:50:00.266 165B INITRS 01:50:00.266 128IB Set fixed grating Set grating position: 16 Set amplifier-gain-bit:0 (Nominal gainstate 2) SCIREC 01:50:00.266 175IB Dur: 00:41:59.666 CSMOS 01:50:00.266 117B Dur: 00:41:53.000 CMDRS 02:32:00.266 157IB Safe NIMS 25 OAPEL NAME: VJBARS Start Time: 90-041/03:40:21.600 (VCA - 02:28:27.99) Tape Start: 90-041/03:42:02.933 Mosaic End: 90-041/04:01:37.600 Tape End: 90-041/04:02:00.933 (VCA - 02:06:48.66) APPROXIMATE START GEOMETRY: Sub-spacecraft Latitude: 7.4 N Sub-spacecraft Longitude: 356.3 W Phase Angle: 142.6 NIMS INSTRUMENT MODE: Longmap NIMS GAIN STATE: 2 ("Nominal" sensitivity) AVERAGE NIMS SPATIAL RESOLUTION: 26 km OBJECTIVE: Acquire 26 high-spectral-resolution START/STOP 20-nimsel mosaics to obtain detailed spectroscopic information on the latitudinal and longitudinal variation of water and CO on 25 km scales. DESIGN: General design: Longmap Start/Stop, non-contiguous sampling Details: Spacecraft distance at the end of the OAPEL is 44644 km, yielding a nimsel FOV resolution of 0.0005*44644 = 22.3 km. At the beginning, the cloudtops are 52431 km away, yielding a nimsel resolution of 26.2 km. Three longmap mode integrations of each nimsel are acquired in order to ensure boom clearance for each grating position. A longmap integration time, 8.666 secs, is assumed for overhead in moving from one location to another, except between longitudinal strips. 6 observations are first observed along the westernmost meridian (6 degrees W. longitude) covering temperate and equatorial latitudes. Then 12 observations are acquired pole-to-pole (with gaps) along the central meridian (357 degrees), followed by 6 along the easternmost meridian (339 degrees west). Then, two separate observations, upstream and downstream of Maxwell Montes, are accumulated. Thus, 26 observations are acquired during the 20 minute period. corresponding to 520 NIMS FOV's (nimsels). The semidiameter of Venus is about arcsin(1/(7.27Rv + 1) = 0.1212 radians. Thus some 2*0.1212/0.0005 = 485 nimsels span the disk, or about 24 Nims observations at 20 nimsels per observation. The 12 27 central-meridian observations consequently cover only about 50% of this meridian, leaving 50% gaps. Similar gaps are used on the nearby parallel observations, which are meant as second and third samplings of the low-latitudes (plus Maxwell Montes) covered in the central-meridian observations. PA SEQUENCE: PA Start Time PA ID Comments SCITLM 90-041/03:42:00.266 176IC EHRMPW TARGET 03:42:00.266 165F INITRS 03:42:00.266 128IC Set longmap Set grating position: 0 SCIREC 03:42:00.266 175IC Dur: 00:19:53 CSMOS 03:42:00.266 117R Dur: 00:19:53 28 OAPEL NAME: VPDIN2 Start Time: 90-041/04:02:08.266 (VCA - 02:06:41.32) Tape #1 Start: 90-041/04:03:49.600 Tape #1 End: 90-041/04:33:26.266 Tape #2 End: 90-041/04:34:54.266 Tape #3 End: 90-041/05:03:16.933 Mosaic end: 90-041/05:03:48.266 (VCA - -1:05:01.32) APPROXIMATE START GEOMETRY: Sub-spacecraft Latitude: 4.9 N Sub-spacecraft Longitude: 358.9 W Phase angle: 140.1 NIMS INSTRUMENT MODE: Fixed Grating (Grating position 16) NIMS GAIN STATE: 2 ("Nominal" sensitivity) AVERAGE NIMS SPATIAL RESOLUTION: 18 km OBJECTIVE: Obtain high-spatial resolution (11-24 km) multi-spectral imagery to compare with previous VPDIN1 to measure lower-atmosphere wind speeds and directions. Determine the spatial scales of localized middle-atmosphere features. Examine, in particular, the effect of high terrain in the Ishtar Terra and Maxwell Montes regions on atmospheric dynamics in the lower atmosphere. DESIGN: General design: Fixed grating (1 grating position) Contiguous sampling (1500 microrads/sec slewrate) 10 pixel overlap between swaths Details: Spacecraft distance at end (VCA-00:45) is 22222 km, yielding 11.1 km/nimsel, and a planetary diameter of 873 nimsels (distance to center of Venus is 4.619 Venus radii. Angular semi-diameter is arcsin(1/4.619) = 12.5 degrees or 0.218 radians or 436.5 nimsels. Diameter is just twice this.) An East-west swath over +-21.6 degrees of longitude is approximately sin(21.6)*angular diameter = 321 nimsels. At beginning (VCA-01:45), distance is 43875 km or 7.146 rV. Planetary diameter is 14.1 degrees = 0.246 radians, spanning some 492 nimsels, and an East-West swath extends over 181 Nimsels. 31 Submosaic # # Strips Cone Delta-S Strip Duration 1 10 80.0 00:00:56 2 10 98.0 00:01:08 3 10 104.0 00:01:14 4 6 112.0 00:01:22 5 4 140.0 00:01:45 PA SEQUENCE: PA Start Time PA ID Comments SCITLM 90-041/04:04:00.266 176ID EHRMPW TARGET 04:04:00.266 165C INITRS 04:04:00.266 128ID Set fixed grating Set grating position: 16 SCIREC 04:04:00.266 175ID Dur: 00:29:30 CSMOS 04:04:00.266 117C Dur: 00:59:53 SCIREC 04:35:32.933 175IP Dur: 00:28:11.200 SCITLM 04:35:32.937 176IP EHRMPW DATA MODES: Mode Start Time Commments EHRMPW 04:04:00.266 SCITLM 176ID R115 04:33:30.266 PWS PA runs to 04:34:54.266 EHRMPW 04:35:32.033 SCITLM 176IP 32 OAPEL NAME: VLSN Start Time: 90-041/05:31:44.266 (VCA - 00:37:05.32) Tape Start: 90-041/05:32:54.933 Mosaic End: 90-041/05:38:52.933 Tape End: 90-041/05:38:54.933 (VCA - 00:30:54.66) APPROXIMATE START GEOMETRY: Sub-spacecraft Latitude: 20.2 S Sub-spacecraft Longitude: 26.4 W Phase angle: 109.9 NIMS INSTRUMENT MODE: Longspectrometer NIMS GAIN STATE: 4 (Most sensitive) AVERAGE NIMS SPATIAL RESOLUTION: 12 km OBJECTIVE: Determine the vertical profile of oxygen and other trace minor species near the anti-subsolar point. Compare with subsequent VLSD observation to determine daytime/nightime differences in oxygen chemistry. DESIGN: General design: Long spectrometer (fixed mirror) -20 to 230 km covered in one swath Details: Spacecraft distance at -00:20 is 15818 km to the cloudtops. Limb is about 1 Venus radius farther away. Limb distance is thus about 21950 km at the end of the observation. At the beginning, at -00:26 the cloudtops are 17045 km away, implying the limb is about 23000 km away. At the end, the 250 km swath is some 11.4 milliradians long. The slew rate to cover this in 360 seconds is 32 microradians/second. PA SEQUENCE: PA Start Time PA ID Comments SCITLM 90-041/05:32:48.933 176IE EHRMPW TARGET 05:32:48.933 165D INITRS 05:32:48.933 128IE Set longspectrometer Set grating position: 0 Set ampl-gain-bit: 1 SCIREC 05:32:48.933 175IE Dur: 00:05:59.666 CSMOS 05:32:48.933 117D Dur: 00:05:53.000 CMDRS 05:38:42.266 157IE Safe NIMS 35 OAPEL NAME: VSLD Start Time: 90-041/06:07:44.933 (VCA - 00:01:04.66) Tape Start: 90-041/06:08:55.600 End Mosaic: 90-041/06:12:55.600 Tape End: 90-041/06:13:00.266 (VCA + 00:04:10.68) APPROXIMATE START GEOMETRY: Sub-spacecraft Latitiude: 40.4 S Sub-spacecraft Longitude: 66.2 W Phase angle: 75.0 NIMS INSTRUMENT MODE: Longspectrometer NIMS GAIN STATE: 4 (Most sensitive) AVERAGE NIMS SPATIAL RESOLUTION: 10 km OBJECTIVE: Determine the vertical profile of oxygen and other trace constituents near the sub-solar point. Compare with previous VSLN observations to determine daytime/nighttime difference in oxygen chemistry. DESIGN: General design: Long spectrometer (fixed mirror) - 10 to 260 km covered in one swath Details: Spacecraft distance at +00:10 is 14398 km to sub-s/c point. Limb is at 90 degrees phase, i.e., 1 Venus radius further away => abut 20500 km away. Km/Nimsel = 0.0005*20500 = 10.3 km. Swath is to be 270 km long, or 26.3 nimsels. Covering this distance, 26.3 * 0.0005 rads = 13.2 milliradians in 240 seconds implies a slew rate of 55 microradians/second. PA SEQUENCE: PA Start Time PA IDComments SCITLM90-041/06:09:00.266 176IF EHRMPW TARGET90-041/06:09:00.266 165E INITRS90-041/06:09:00.266 128IE Set longspectrometer SCIREC90-041/06:09:00.266 175IF Dur: 00:03:59.666 CSMOS90-041/06:09:00.266 117E Dur: 00:03:53.000 38 RIDE-ALONG SCIENCE ACTIVITIES All ride-along activities are in longmap, SSI start/stop mosaics. NIMS gain state is set up at the beginning of each day's observations. OAPEL Gain Km per Sub-spacecraft Record Start Time Record End Time Nimsel Lat W. Lon. VLMB01 1 18.9 27.1 S 151.7 90-041/07:37:54 90-040/07:38:52 19.3 26.7 S 152.3 07:39:25 07:40:23 19.5 26.5 S 152.6 07:40:56 07:41:54 19.8 26.1 S 153.1 07:42:27 07:43:25 20.0 26.0 S 153.4 07:43:59 07:44:56 VLMB02 41.5 14.9 S 167.7 90-041/09:37:13 90-041/09:38:11 VFT201 1 286 4.3 S 177.8 90-042/07:13:24 90-042/07:14:26 VFT202 288 4.3 S 177.8 90-042/07:23:34 90-042/07:24:32 VFT203 294 4.3 S 177.8 90-042/07:53:54 90-042/07:54:52 VFT204 309 4.1 S 177.9 90-042/09:13:47 90-042/09:14:45 VFT205 311 4.1 S 177.9 90-042/09:23:53 90-042/09:24:52 VFT206 317 4.1 S 177.9 90-042/09:53:13 90-042/09:54:11 VFT207 332 4.0 S 177.9 90-042/11:13:06 90-042/11:14:03 VFT208 334 4.0 S 177.9 90-042/11:23:12 90-042/11:24:10 VFT209 339 4.0 S 177.9 90-042/11:53:32 90-042/11:53:49 Track reversal 11:53:49 11:53:54 Finish 11:53:54 11:54:30 VFT210 354 3.9 S 177.9 90-042/13:13:25 90-042/13:14:23 VFT211 360 3.9 S 177.9 90-042/13:43:45 90-042/13:44:43 VFT212 377 3.8 S 177.8 90-042/15:13:44 90-042/15:14:42 VFT213 382 3.8 S 177.8 90-042/15:43:04 90-042/15:44:02 VFT214 399 3.7 S 177.8 90-042/17:13:03 90-042/17:14:01 VFT215 405 3.7 S 177.8 90-042/17:43:23 90-042/17:44:21 VFT216 422 3.7 S 177.8 90-042/19:13:22 90-042/19:14:20 VFT217 427 3.6 S 177.7 90-042/21:43:42 90-042/19:44:40 VFT218 444 3.6 S 177.7 90-042/21:13:41 90-042/21:14:40 VFT219 450 3.6 S 177.7 90-042/21:44:02 90-042/21:45:00 VFT101 2 542 3.4 S 177.4 90-043/05:58:28 90-043/05:58:56 VLTNG02 545 3.3 S 177.3 90-043/06:13:35 90-043/06:13:49 VFT102 564 3.3 S 177.3 90-043/07:58:47 90-043/07:59:14 VFT103 587 3.3 S 177.2 90-043/09:58:05 90-343/09:58:33 VFT104 609 3.2 S 177.1 90-043/11:58:25 90-043/11:58:53 VFT105 631 3.2 S 177.0 90-043/13:57:43 90-043/13:58:11 39 OAPEL Gain Km per Sub-spacecraft Record Start Time Record End Time Nimsel Lat W. Lon. VGLI01 3 810 3.0 S 176.2 90-044/05:58:17 90-044/05:59:15 VGLI02 832 3.0 S 176.1 90-044/07:58:36 90-044/07:59:34 VGLIR03 854 3.0 S 176.0 90-044/10:00:57 90-044/10:01:55 VGLIRO4 877 3.0 S 175.9 90-044/12:00:14 90-044/12:01:13 VGL03 4 1076 2.8 S 174.9 90-045/05:28:05 90-045/05:29:15 VGL04 1095 2.8 S 174.7 90-045/07:28:05 90-045/07:28:33 VGL05 1 1335 2.7 S 173.4 90-046/04:58:16 90-046/04:58:44 VGL06 1357 2.7 S 173.3 90-046/06:58:35 90-046/06:59:03 VGL07 2 1597 2.7 S 171.7 90-047/04:28:46 90-047/04:29:13 VGL08 1619 2.7 S 171.8 90-047/06:28:05 90-047/06:28:32 VGL09 3 1860 2.6 S 170.4 90-048/03:58:15 90-048/03:58:43 VGL10 1881 2.6 S 170.3 90-048/05:58:35 90-048/05:59:00 40