! $Id: 4518,v 4.1 1994/11/17 19:04:27 pepsa Exp $ ! $Id: 4518,v 4.1 1994/11/17 19:04:27 pepsa Exp $ ! File: 4518C.PROP ! Database: PEPDB ! Date: 22-FEB-1994:15:52:49 coverpage: title_1: HIGH RESOLUTION SPECTROSCOPY OF VENUS CLOUDS-CYC3 HIGH sci_cat: SOLAR SYSTEM sci_subcat: INNER PLANETS proposal_for: GO pi_fname: LARRY pi_mi: W pi_lname: ESPOSITO pi_inst: U.COLORADO LASP pi_country: USA hours_pri: 0.08 num_pri: 1 wf_pc: N hrs: Y time_crit: Y funds_length: 12 off_fname: LAURENCE off_mi: D off_lname: NELSON off_title: DIRECTOR off_inst: 1760 off_addr_1: OFFICE OF CONTRACTS & GRANTS off_city: BOULDER off_state: CO off_zip: 80309 off_country: USA off_phone: 303/492-3695 ! end of coverpage abstract: line_1: Observations of the Venus atmosphere are important to understand line_2: the cloud chemistry and dynamics. Sulfur dioxide is an indicator of line_3: surface geological activity and, thus, the geologic evolution of line_4: Venus. Ground based observers, Pioneer Venus, IUE and rockets have line_5: observed the Venus UV spectrum and found significant temporal line_6: changes over the past decade. The HST has the capability to extend line_7: these observations in the decade the 90s at higher spectral line_8: resolution than Pioneer Venus and spatial resolution than IUE. It is line_9: important that these observations continue the monitoring of SO2 line_10: (Pioneer Venus mission ended in 1992). line_11: At elongation, the Sun angle is more than 45 degrees making the line_12: observations of Venus possible while HST is in Earth shadow. We line_13: propose to observe Venus in Earth shadow using blind pointing line_14: in the wavelength regions centered on 2070A and 2160A line_15: to identify and measure SO2, SO and other absorbers. In addition, line_16: we plan to make an observation with the Echelle-B grating to study line_17: the saturation of SO2 bands which has a critical importance for line_18: the chemistry of Venus clouds. ! ! end of abstract general_form_proposers: lname: ESPOSITO fname: LARRY title: PI mi: W inst: U.COLORADO LASP country: USA ! lname: NA fname: CHAN mi: Y inst: U.COLORADO LASP country: USA ! ! end of general_form_proposers block general_form_text: question: 2 section: 1 line_1: Paper copy only. ! question: 3 section: 1 line_1: Because of the Sun constraint, HST will initially be pointed 50 line_2: degrees from the Sun, several degrees beyond Venus. After the Sun line_3: sets behind the Earth's limb, HST will slew on gyros to the center line_4: of Venus, and offset point to 5.9 seconds in the Sunward direction. line_5: The observations follow: GHRS G200M with LSA (1 minute), centered line_6: on 2070A; GHRS G200M with LSA (1 minute), centered on 2160A; GHRS line_7: Echelle-B centered on 2070A(2 minutes). After the exposures, line_8: slew to a safe position. ! question: 4 section: 1 line_1: The observation of Venus in the middle UV is crucial to measure line_2: the abundance of SO2 on Venus. The Earth atmosphere is opaque line_3: at these wavelenghths. Pioneer Venus has now burned up in the line_4: Venus atmosphere. IUE sensitivity and pointing accuracy are too line_5: low. Continuing studies require HST monitoring. The GHRS echelle line_6: provides the best spectral resolution and can identify the level line_7: of band saturation. ! question: 5 section: 1 line_1: Venus is most safely observed near its maximum elongation, when line_2: it is furthest from the Sun. A short slew will allow pointing to line_3: Venus while HST is in the Earth's shadow. Venus is more than 43 line_4: degrees from the Sun from 31 May 1993 to 12 July 1993. ! question: 6 section: 1 line_1: None. ! question: 7 section: 1 line_1: We will use the latest GHRS calibration and STSDAS to reduce the line_2: data. Further data analysis will occur at Colorado and SWRI. We line_3: use a multiple scattering RT model and consider vertically line_4: inhomgeneous distributions for absorbers and scatterers. This line_5: method has been exstensively used to analyze PV, IUE, and rocket line_6: observations. The results from HST will be directly compared to line_7: previous findings. ! question: 8 section: 1 line_1: None. ! question: 9 section: 1 line_1: None. ! question: 10 section: 1 line_1: PI academic year support. Computing facilities and costs. Undergrad line_2: students through the UROP Program. ! !end of general form text general_form_address: lname: Esposito fname: Larry mi: W category: PI inst: U.Colorado LASP addr_1: LASP addr_2: Campus Box 392 city: Boulder state: CO zip: 803090392 country: USA phone: 303/492-7325 telex: 910/940-3441 ! ! end of general_form_address records fixed_targets: targnum: 3 name_1: VENUS+5D descr_1: I,606 pos_1: RA = 235.1777384D +/- 0.00001D, pos_2: DEC = -15.5724451D +/- 0.00001D equinox: 2000 comment_1: FIXED POINTING AT ELONG comment_2: 51.88 DEG FROM SUN ON 1/9 comment_3: AND GETTING FARTHER... ! end of fixed target records solar_system_targets: targnum: 1 name_1: VENUS descr_1: PLANET VENUS lev1_1: STD = VENUS lev2_1: TYPE = POS_ANGLE, lev2_2: ANG = 0, lev2_3: RAD = 5.9, lev2_4: REF = SUN wind_1: VENUS ELONGATION comment_1: SUN REFERENCE MORE DIRECT comment_2: THAN CELESTIAL REFERENCE comment_3: SUGGESTED BY STORRS. fluxnum_1: 1 fluxval_1: F(2070) = 10 +/- 5 E-10 ! targnum: 2 ! name_1: VENUS+5D ! descr_1: PLANET VENUS ! lev1_1: STD = VENUS ! lev2_1: TYPE = POS_ANGLE, ! lev2_2: ANG = 180, ! lev2_3: RAD = 5 D, ! lev2_4: REF = SUN ! wind_1: VENUS ELONGATION ! comment_1: SUN REFERENCE MORE DIRECT ! comment_2: THAN CELESTIAL REFERENCE ! comment_3: SUGGESTED BY STORRS. ! COMMENT_4: 5 DEGREE ANTISUNWARD OFFSET ! COMMENT_5: FOR SAFE POINTING TEST. ! fluxnum_1: 1 ! fluxval_1: F(2070) = 10 +/- 5 E-10 ! ! end of solar system targets ! No generic target records found exposure_logsheet: linenum: 0.500 targname: VENUS+5D config: S/C opmode: DATA aperture: V1 num_exp: 1 time_per_exp: 1S req_1: CYCLE 4 / 0.5-3.5; req_2: PCS MODE F; req_3: SEQ 0.5-3.5 NO GAP; comment_1: POINTING BEYOND 50 DEG comment_2: SOLAR AVOIDANCE LIMIT. comment_3: EACH LINE ITS OWN OBSET. ! linenum: 1.000 targname: VENUS config: HRS opmode: ACCUM aperture: 2.0 sp_element: G200M wavelength: 2070 num_exp: 1 time_per_exp: 1M PARAM_1: SPYBAL=NO s_to_n: 25 s_to_n_time: 1M fluxnum_1: 1 priority: 1 req_1: GUID TOL 5"; req_2: DARK TIME; req_3: PCS MODE C; comment_1: MAY ACQ SINGLE GS, THEN comment_2: DROP TO GYRO TO OBSERVE. comment_3: EACH LINE ITS OWN OBSET. linenum: 1.500 targname: VENUS+5D config: S/C opmode: DATA aperture: V1 num_exp: 1 time_per_exp: 1S req_2: PCS MODE F; comment_1: POINTING BEYOND 50 DEG comment_2: SOLAR AVOIDANCE LIMIT. comment_3: EACH LINE ITS OWN OBSET. ! linenum: 2.000 targname: VENUS config: HRS opmode: ACCUM aperture: 2.0 sp_element: G200M wavelength: 2160 num_exp: 1 time_per_exp: 1M PARAM_1: SPYBAL=NO s_to_n: 25 s_to_n_time: 1M fluxnum_1: 1 priority: 2 req_1: GUID TOL 5"; req_2: DARK TIME; req_3: PCS MODE C; comment_1: MAY ACQ SINGLE GS, THEN comment_2: DROP TO GYRO TO OBSERVE. comment_3: EACH LINE ITS OWN OBSET. linenum: 2.500 targname: VENUS+5D config: S/C opmode: DATA aperture: V1 num_exp: 1 time_per_exp: 1S req_2: PCS MODE F; comment_1: POINTING BEYOND 50 DEG comment_2: SOLAR AVOIDANCE LIMIT. comment_3: EACH LINE ITS OWN OBSET. ! linenum: 3.000 targname: VENUS config: HRS opmode: ACCUM aperture: 2.0 sp_element: ECH-B wavelength: 2070 num_exp: 1 time_per_exp: 2M PARAM_1: SPYBAL=NO s_to_n: 25 s_to_n_time: 2M fluxnum_1: 1 priority: 3 req_1: GUID TOL 5"; req_2: DARK TIME; req_3: PCS MODE C; comment_1: MAY ACQ SINGLE GS, THEN comment_2: DROP TO GYRO TO OBSERVE. comment_3: EACH LINE ITS OWN OBSET. linenum: 3.500 targname: VENUS+5D config: S/C opmode: DATA aperture: V1 num_exp: 1 time_per_exp: 1S req_2: PCS MODE F; comment_1: POINTING BEYOND 50 DEG comment_2: SOLAR AVOIDANCE LIMIT. comment_3: EACH LINE ITS OWN OBSET. ! ! end of exposure logsheet ! No scan data records found