! File: 2254C.PROP ! Database: PEPDB ! Date: 17-FEB-1994:04:13:37 coverpage: title_1: PCSOLT#7 ALTERNATE CONTROL MODES proposal_for: OV/OLT pi_fname: GERRY pi_lname: NURRE pi_inst: MARSHALL SPACE FLIGHT CENTER pi_country: USA hours_pri: 1.00 num_pri: 1 fgs: X time_crit: X ! end of coverpage abstract: line_1: line_2: This Observatory Level Test provides data on the Pointing Control System line_3: performance while in alternate control modes. ! ! end of abstract general_form_proposers: lname: NURRE fname: GERRY inst: MARSHALL SPACE FLIGHT CENTER country: USA ! lname: BEALS fname: GARY inst: LOCKHEED MISSILES & SPACE COMPANY country: USA ! ! end of general_form_proposers block general_form_text: question: 2 section: 1 line_1: line_2: This activity characterizes four control modes that will increase the line_3: operational flexibility of the mission. ! question: 3 section: 1 line_1: line_2: The following sequence is performed: line_4: 1) The HST is first slewed to NGC 188 in the north ecliptic polar region. line_5: This star field is used by the mini-OFAD and will be well known. The line_6: Roll Angle is selected such that at least two FHST's have stars within line_7: their Fields-of-View. line_9: 2.5) FGS1 and FGS3 acquire guide stars in coarse track, while FGS2 begins fine line_10: lock on the astrometry target. The observer is configured for two FGS's line_11: in coarse track. The astrometry FGS is used to monitor drift and jitter. line_12: This configuration is maintained for ten minutes. line_14: 3) FGS1 or FGS3 acquires a guide star in fine lock, while one FHST begins line_15: tracking roll reference star. FGS2 again acquires the astrometry target. line_16: The observer is configured for one FGS in fine lock and one FHST. FGS2 line_17: is used to monitor drift and jitter. This configuration is maintained line_18: for ten minutes. line_20: 3.5) The second FHST begins tracking a star and FGS2 finds the astrometry line_21: target to provide drift and jitter data. This configuration is line_22: maintained for ten minutes. ! question: 3 section: 2 line_1: line_2: 4) FGS2 acquires the astrometry target once more as the vehicle is line_3: controlled exclusively by the gyros. FGS2 is used to monitor drift and line_4: jitter. This configuration is maintained for ten minutes. line_11: As each acquisition progresses, FGS monitors are observed to verify line_12: proper execution of the acquisition sequence. While locked on each set of line_13: guide stars, RGA rate data and FGS interferometer output and star selector line_14: angles is collected. A statistical analysis of this data quantifies the PCS line_15: performance. The astrometry FGS provides an independent check on the pointing line_16: error. Analysis of the observer data at this time demonstrates the ability of line_17: the PCS to estimate the pointing error. ! question: 6 section: 1 line_1: line_2: A portion of this activity requires star availability for at least two line_3: FHST's. ! question: 7 section: 1 line_1: line_2: Data reduction is accomplished using the SAS package. Simulation support line_3: is provided by LMSC using currently available digital simulations. ! question: 8 section: 1 line_1: line_2: This activity is described in Activity Description K107 - Alternate line_3: Control Modes. ! question: 9 section: 1 line_1: line_2: Results and analysis will appear in the "PCS On-Orbit Performance Report". ! question: 10 section: 1 line_1: line_2: Telemetry monitoring and data analysis is performed at the HOSC. ! !end of general form text general_form_address: lname: NURRE fname: GERRY category: PI inst: MARSHALL SPACE FLIGHT CENTER addr_1: GEORGE C. MARSHALL SPACE FLIGHT CENTER city: MARSHALL SPACE FLIGHT CENTER state: AL zip: 35812 country: USA phone: (205)544-1424 ! lname: BEALS fname: GARY inst: LOCKHEED MISSILES & SPACE addr_1: 1111 LOCKHEED WAY, 64-20, B/579, F5 city: SUNNYVALE, state: CA zip: 940883504 country: USA phone: (408)742-8058 ! ! end of general_form_address records fixed_targets: targnum: 1 name_1: NGC188AST descr_1: ASTROMETRY TARGET FOR PCS OLT #7 pos_1: RA=0H 30M 43.51S, pos_2: DEC=84D 42' 48.21" equinox: 1950 fluxval_1: V=9.1 ! ! end of fixed targets ! No solar system records found ! No generic target records found exposure_logsheet: linenum: 1.500 targname: NGC188AST config: FGS opmode: POS aperture: 2 sp_element: F583W num_exp: 1 time_per_exp: 10M priority: 1 comment_1: USE FGS'S ONLY FOR C0NTROL. GUIDING comment_2: FGS'S IN COARSE TRACK. ! linenum: 2.000 targname: ^ config: ^ opmode: ^ aperture: ^ sp_element: ^ num_exp: ^ time_per_exp: ^ priority: ^ comment_1: USE 1 FGS AND 1 FHST FOR CONTROL. ! linenum: 2.500 targname: ^ config: ^ opmode: ^ aperture: ^ sp_element: ^ num_exp: ^ time_per_exp: ^ priority: ^ comment_1: USE TWO FHST'S FOR CONTROL. ! linenum: 3.000 targname: ^ config: ^ opmode: ^ aperture: ^ sp_element: ^ num_exp: ^ time_per_exp: ^ priority: ^ comment_1: USE GYROS ONLY FOR CONTROL. ! linenum: 4.000 targname: DARK config: S/C opmode: DATA aperture: NONE num_exp: 1 time_per_exp: 10M priority: 1 param_1: FORMAT=PN, req_1: PAR WITH 1.5; comment_1: PROVIDE PN TELEMETRY. ! linenum: 4.100 targname: DARK config: S/C opmode: DATA aperture: NONE num_exp: 1 time_per_exp: 10M priority: 1 param_1: FORMAT=PN, req_1: PAR WITH 2.0; comment_1: PROVIDE PN TELEMETRY. ! linenum: 4.200 targname: DARK config: S/C opmode: DATA aperture: NONE num_exp: 1 time_per_exp: 10M priority: 1 param_1: FORMAT=PN, req_1: PAR WITH 2.5; comment_1: PROVIDE PN TELEMETRY. ! linenum: 4.300 targname: DARK config: S/C opmode: DATA aperture: NONE num_exp: 1 time_per_exp: 10M priority: 1 param_1: FORMAT=PN, req_1: PAR WITH 3.0; comment_1: PROVIDE PN TELEMETRY. ! ! end of exposure logsheet ! No scan data records found