!  File:  4723C.PROP
!  Database:  PEPDB
!  Date:  22-FEB-1994:23:53:32

coverpage:

  title_1:         WF/PC CALIBRATION UV PIPE TEST
    proposal_for:  CAL/WFC
    pi_title:      DR.
    pi_fname:      JOHN
    pi_mi:         W.
    pi_lname:      MACKENTY
    pi_inst:       ST SCI
    pi_country:    USA
    pi_phone:      (410)338-4559
    keywords_1:    UV FLOOD
    time_crit:     X
! end of coverpage

abstract:

    line_1:        In order to test the throughput of the UV lightpipe, the WFPC
    line_2:        CCDs will first be cleaned of UV blocking contaminants by means
    line_3:        of a flash decontamination.  This will be followed by images of
    line_4:        the sun being taken through the UV lightpipe followed by images
    line_5:        of a bright UV standard star through the lightpipe.

!
! end of abstract

general_form_proposers:

  lname:           WF/PC TIB/SESD
    inst:          ST SCI

!
! end of general_form_proposers block

general_form_text:

  question:        2
    section:       1
    line_1:        The WF/PC CCD detectors must retain a backside e- charge on the thinned silicon
    line_2:        bulk material in order to alleviate a pernicious hysteresis condition which
    line_3:        exists in these devices.  This charge is obtained by exposing the CCDs to
    line_4:        UV light by introducing sunlight through the "UV Light Pipe", a 3-inch
    line_5:        telescope which has a field-of-view of 19 arc minutes, approximately 1.5
    line_6:        degrees off of the -V1 axis of the OTA FOV. The process of charging, known
    line_7:        as the "UV Flood" must be done after the CCD windows have been cleansed of any
    line_8:        hydrocarbon contaminants via a "High Temperature Decontamination Procedure".
    line_9:        These activities take several days of dedicated spacecraft time, and must
    line_10:       be carefully monitored as the WF/PC is in a non-standard configuration
    line_11:       during this interval.  Potential health and safety risks have been
    line_12:       identified, and plans formulated to circumvent problems are in place.
    line_13:       This UV Flood (Proposal 3971) may be executed at any time, as needed, if
    line_14:       the detector hysteresis problem returns spontaneously, or induced following
    line_15:       a warm-up of the detectors.

!

  question:        2
    section:       2
    line_1:        The UV Light Pipe actually contains multiple optical elements with a total
    line_2:        of 13 optical surfaces.  Assuming that the transmissivity and/or reflectivity of
    line_3:        these surfaces have remained unchanged since the pre-launch epoch then a
    line_4:        sufficient level of charge may obtained on the PC chips after 15 orbits of
    line_5:        exposing the CCDS to UV sunlight, and 4 orbits for the WFC.  There is, however,
    line_6:        sufficient reason to believe that the optical throughput of the UV Light
    line_7:        channel may have degraded over time.  While most of the optical elements are in
    line_8:        a contained housing which is believed to be well sealed, both the external (M1)
    line_9:        mirror and the exterior surface of the objective lens are exterior to HST and
    line_10:       interact with the mono-atomic oxygen environment of near-earth orbit.  Continual
    line_11:       bombardment by these and other particles may have reduced the total UV flux
    line_12:       which can be delivered through the light pipe.  The UV flood "flip mirror" and
    line_13:       the last optical surface of the Light Pipe have been exposed to the molecular
    line_14:       contaminants which are known to exist in the WF/PC.  While these are not cold
    line_15:       surfaces, so they are not expected to actively accumulate these contaminants, it
    line_16:       is not known that these optical elements have not suffered some degradation
    line_17:       in UV throughput.

!

  question:        2
    section:       3
    line_1:        Prior to executing a UV flood, the UV throughput of the Light Pipe must
    line_2:        be ascertained.  If the throughput has been degraded due to contamination of
    line_3:        any or all of the optical surfaces in the Pipe then the time required to UV
    line_4:        Flood the CCD would have to be increased (to obtain the same level of
    line_5:        integrated flux).  If the throughput of the Light Pipe has declined to
    line_6:        by as much as a factor of 4 then backside charging of the CCDs by a UV Flood
    line_7:        may become impossible (as the UV Flood must be done when the chips are warm, and
    line_8:        the charge would bleed off as quickly as it accumulates).  Before commiting the
    line_9:        resources and spacecraft time required to perform UV flood we must know if a
    line_10:       flood can be successfully performed, and if so what the throughput of the Light
    line_11:       Pipe actually is so the UV Flooding duration can be adjusted (i.e. proposal
    line_12:       3971 modified).

!

  question:        2
    section:       4
    line_1:
    line_2:        This proposal will determine the degradation in UV transmissivity of the Light
    line_3:        Pipe optical system by observing the Sun through the Light Pipe.  These
    line_4:        observations will be compared to the last set of (so called) "SUNPIX" images
    line_5:        taken in December of 1990.  This temporal baseline is sufficiently long enough
    line_6:        to determine from the differential photometry how the opacity of this optical
    line_7:        system has changed (and may allow an extrapolation into the future).  In
    line_8:        addition, a UV Standard star will be observed through the light channel in
    line_9:        order to ascertain the absolute level UV flux which is presented to the WFPC
    line_10:       CCDs through the light channel. Both of these sets of observations MUST be done
    line_11:       shortly after the CCD windows have been cleaned of their uniform layer of
    line_12:       UV-opaque contaminants via a standard "Low Temperature Decontamination
    line_13:       Procedure".  This procedure must be executed in real time.  In order to assure
    line_14:       that the necessary command uplink windows are available in which that procedure
    line_15:       must be executed this proposal will set up those uplinks via a number of timed
    line_16:       S/C DATA (REQ UPLINK) exposure lines.

!

  question:        3
    section:       1
    line_1:        Perform a Flash Decontamination via RT command.
    line_2:        (Uplinks required for RT procedure will be scheduled via SMS requests)
    line_3:        Orient HST to put SUN in UV Light Pipe.
    line_4:        Configure WFPC to UVOBS mode (Blocking filters in place prior to moving
    line_5:        flood mirror)
    line_6:        Take 4 WFC (full frame R/O) "SUNPIX" images, bracketing best exposure time.
    line_7:        Orient HST to put UV Standard Star in Light Pipe.
    line_8:        Take 4 WFC (full frame R/O) stellar images through the light pipe.
    line_9:        Recondition WFPC for normal science operations.

!
!end of general form text

general_form_address:

  lname:           MACKENTY
    fname:         JOHN
    mi:            W.
    category:      PI
    inst:          ST SCI
    addr_1:        3700 SAN MARTIN DRIVE
    city:          BALTIMORE
    state:         MD
    zip:           21218
    country:       USA
    phone:         (410)338-4559

!

  lname:           SCHNEIDER
    fname:         GLENN
    category:      CON
    inst:          ST SCI
    addr_1:        3700 SAN MARTIN DRIVE
    city:          BALTIMORE
    state:         MD
    zip:           21218
    country:       USA
    phone:         (410)338-4717

!

  lname:           RITCHIE
    fname:         CHRISTINE
    inst:          ST SCI
    addr_1:        3700 SAN MARTIN DRIVE
    city:          BALTIMORE
    state:         MD
    zip:           21218
    country:       USA
    phone:         (410) 338-5042

!
! end of general_form_address records

fixed_targets:

    targnum:       1
    name_1:        HD48915
    name_2:        ALPHA-CMA
    name_3:        SIRIUS
    descr_1:       J,702
    pos_1:         RA = 06H 45M 08.90S +/- 1S,
    pos_2:         DEC = -16D 42' 58.0" +/- 1",
    equinox:       2000
    fluxnum_1:     1
    fluxval_1:     V= -1.46

!

    targnum:       2
    name_1:        HD122451
    name_2:        BETA-CEN
    descr_1:       J,702
    pos_1:         RA = 14H 03M 49.40S +/- 1S,
    pos_2:         DEC = -60D 22' 22.0" +/- 1",
    equinox:       2000
    fluxnum_1:     1
    fluxval_1:     V= 0.61

!

    targnum:       3
    name_1:        PSEUDOTARG1
    descr_1:       J,702
    pos_1:         RA = 18H 45M 08.90S +/- 1S,
    pos_2:         DEC = 16D 42' 58.0" +/- 1",
    equinox:       2000
    fluxnum_1:     1
    fluxval_1:     V= -1.46

!

    targnum:       4
    name_1:        PSEUDOTARG2
    descr_1:       J,702
    pos_1:         RA = 02H 03M 49.40S +/- 1S,
    pos_2:         DEC = 60D 22' 22.0" +/- 1",
    equinox:       2000
    fluxnum_1:     1
    fluxval_1:     V= 0.61

!
! end of fixed targets

solar_system_targets:

  targnum:         5
    name_1:        SUN
    descr_1:       OTHER UV SOURCE
    lev1_1:        STD = SUN, ACQ = 30

!
! end of solar system targets

! No generic target records found

exposure_logsheet:

    linenum:       1.000
    sequence_1:    DEFINE
    sequence_2:    FLASH
    targname:      DARK
    config:        S/C
    opmode:        DATA
    aperture:      NONE
    time_per_exp:  30M
    priority:      1
    req_1:         REQ UPLINK;
    comment_1:     STEPS 1-8 OF FLASH DECON.
    comment_2:     R/T PROCEDURE.
    comment_3:     INTERLEAVING OF ANY WFPC SU'S FROM
    comment_4:     START OF LINE 1 UNTIL 100M AFTER
    comment_5:     COMPLETION OF LINE 4 IS PROHIBITED.

!

    linenum:       2.000
    sequence_1:    DEFINE
    sequence_2:    FLASH
    targname:      DARK
    config:        S/C
    opmode:        DATA
    aperture:      NONE
    time_per_exp:  40M
    priority:      1
    req_1:         AFTER 1 BY 150M +/- 20M;
    req_2:         REQ UPLINK;
    comment_1:     STEPS 9-10 OF FLASH DECON.
    comment_2:     R/T PROCEDURE.

!

    linenum:       3.000
    sequence_1:    DEFINE
    sequence_2:    FLASH
    targname:      DARK
    config:        S/C
    opmode:        DATA
    aperture:      NONE
    time_per_exp:  15M
    priority:      1
    req_1:         AFTER 2 BY 140M +/- 20M;
    req_2:         REQ UPLINK;
    comment_1:     STEPS 11-15 OF FLASH DECON.
    comment_2:     R/T PROCEDURE.

!

    linenum:       4.000
    sequence_1:    DEFINE
    sequence_2:    FLASH
    targname:      DARK
    config:        S/C
    opmode:        DATA
    aperture:      NONE
    time_per_exp:  10M
    priority:      1
    req_1:         AFTER 3 BY 115M +/- 20M;
    req_2:         REQ UPLINK;
    comment_1:     STEPS 16-18 OF FLASH DECON.
    comment_2:     R/T PROCEDURE.
    comment_3:     WAIT 100M BEFORE OTHER WFPC'S.

!

    linenum:       10.000
    sequence_1:    DEFINE
    sequence_2:    SUNPIX
    targname:      SUN
    config:        S/C
    opmode:        POINTING
    aperture:      V1
    num_exp:       1
    time_per_exp:  1.0S
    priority:      1
    req_1:         PCS MODE C;
    req_2:         SEQ 10-14 NO GAP;
    comment_1:     LINES 11-14 MUST START WITHIN
    comment_2:     AN HOUR OF THIS DUMMY POINTING.

!

    linenum:       11.000
    sequence_1:    DEFINE
    sequence_2:    SUNPIX
    targname:      SUN
    config:        WFC
    opmode:        UVOBS
    aperture:      WFALL
    sp_element:    F122M,F230W
    num_exp:       1
    time_per_exp:  0.5S
    priority:      1
    param_1:       CR-SPLIT=NO,
    param_2:       PRE-FLASH=YES
    req_1:         PCS MODE G;
    req_2:         AFTER 10 BY 30M +/- 30M;
    req_3:         SEQ 11-14 NON-INT;
    comment_1:     TARGET TO BE CHANGED TO ASLAG.
    comment_2:     MAKE SURE THIS IS 0.25 DEGREES
    comment_3:     FROM ANTI-SUN.

!

    linenum:       12.000
    sequence_1:    DEFINE
    sequence_2:    SUNPIX
    targname:      SUN
    config:        WFC
    opmode:        UVOBS
    aperture:      WFALL
    sp_element:    F122M,F230W
    num_exp:       1
    time_per_exp:  2.0S
    priority:      1
    param_1:       CR-SPLIT=NO,
    param_2:       PRE-FLASH=YES
    req_1:         PCS MODE G;
    comment_1:     TARGET TO BE CHANGED TO ASLAG.
    comment_2:     MAKE SURE THIS IS 0.25 DEGREES
    comment_3:     FROM ANTI-SUN.

!

    linenum:       13.000
    sequence_1:    DEFINE
    sequence_2:    SUNPIX
    targname:      SUN
    config:        WFC
    opmode:        UVOBS
    aperture:      WFALL
    sp_element:    F122M,F230W
    num_exp:       1
    time_per_exp:  0.5S
    priority:      1
    param_1:       CR-SPLIT=NO,
    param_2:       PRE-FLASH=NO
    req_1:         PCS MODE G;
    req_2:         SAME ORIENT FOR 13 AS 11;

!

    linenum:       14.000
    sequence_1:    DEFINE
    sequence_2:    SUNPIX
    targname:      SUN
    config:        WFC
    opmode:        UVOBS
    aperture:      WFALL
    sp_element:    F122M,F230W
    num_exp:       1
    time_per_exp:  2.0S
    priority:      1
    param_1:       CR-SPLIT=NO,
    param_2:       PRE-FLASH=NO
    req_1:         PCS MODE G;
    req_2:         SAME ORIENT FOR 14 AS 11;

!

    linenum:       20.000
    sequence_1:    DEFINE
    sequence_2:    STARPIX
    targname:      #
    config:        S/C
    opmode:        POINTING
    aperture:      V1
    num_exp:       1
    time_per_exp:  1.0S
    priority:      1
    req_1:         PCS MODE C;
    req_2:         SEQ 20-24 NO GAP;
    comment_1:     LINES 21-24 MUST START WITHIN
    comment_2:     ONE ORBIT OF THIS DUMMY POINING.

!

    linenum:       21.000
    sequence_1:    DEFINE
    sequence_2:    STARPIX
    targname:      #
    config:        WFC
    opmode:        UVOBS
    aperture:      WFALL
    sp_element:    F122M,F230W
    num_exp:       1
    time_per_exp:  20.0S
    priority:      1
    param_1:       CR-SPLIT=NO,
    param_2:       PRE-FLASH=YES
    req_1:         PCS MODE G;
    req_2:         AFTER 20 BY 45M +/- 45M;
    req_3:         SEQ 21-24 NON-INT;

!

    linenum:       22.000
    sequence_1:    DEFINE
    sequence_2:    STARPIX
    targname:      #
    config:        WFC
    opmode:        UVOBS
    aperture:      WFALL
    sp_element:    F122M,F230W
    num_exp:       1
    time_per_exp:  60.0S
    priority:      1
    param_1:       CR-SPLIT=NO,
    param_2:       PRE-FLASH=YES
    req_1:         PCS MODE G;

!

    linenum:       23.000
    sequence_1:    DEFINE
    sequence_2:    STARPIX
    targname:      #
    config:        WFC
    opmode:        UVOBS
    aperture:      WFALL
    sp_element:    F122M,F230W
    num_exp:       1
    time_per_exp:  200.0S
    priority:      1
    param_1:       CR-SPLIT=NO,
    param_2:       PRE-FLASH=YES
    req_1:         PCS MODE G;

!

    linenum:       24.000
    sequence_1:    DEFINE
    sequence_2:    STARPIX
    targname:      #
    config:        WFC
    opmode:        UVOBS
    aperture:      WFALL
    sp_element:    F122M,F230W
    num_exp:       1
    time_per_exp:  600.0S
    priority:      1
    param_1:       CR-SPLIT=NO,
    param_2:       PRE-FLASH=YES
    req_1:         PCS MODE G;

!

    linenum:       100.000
    targname:      HD48915
    config:        S/C
    opmode:        POINTING
    aperture:      V1
    num_exp:       1
    time_per_exp:  1.0S
    priority:      1
    req_1:         CYCLE 2/100-101;
    comment_1:     WARNING: NEVER SCHEDULE
    comment_2:     FOR EXECUTION
    comment_3:     SEE IMPLEMENTATION PLAN.

!

    linenum:       101.000
    targname:      HD122451
    config:        S/C
    opmode:        POINTING
    aperture:      V1
    num_exp:       1
    time_per_exp:  1.0S
    priority:      1
    comment_1:     WARNING:  NEVER SCHEDULE
    comment_2:     FOR EXECUTION
    comment_3:     SEE IMPLEMENTATION PLAN.

!

    linenum:       200.000
    sequence_1:    USE
    sequence_2:    FLASH
    req_1:         CYCLE 2/200-203;
    comment_1:     CRITICAL TIMING MUST BE ENFORCED.

!

    linenum:       201.000
    sequence_1:    USE
    sequence_2:    SUNPIX
    req_1:         AFTER 200 BY 2D +/- 1D;
    comment_1:     CRITICAL TIMING MUST BE ENFORCED.

!

    linenum:       202.000
    sequence_1:    USE
    sequence_2:    STARPIX
    targname:      PSEUDOTARG1
    req_1:         SEQ 201-202 WITHIN 4.5H;
    req_2:         COND IF HD48915 POSSIBLE;
    req_3:         AT JD2450633.5 +/- 0.01D;
    comment_1:     CRITICAL TIMING MUST BE ENFORCED.
    comment_2:     PRIMARY TARGET IS HD48915. SELECT
    comment_3:     PRIMARY TARGET IF POSSIBLE. IF HD48915
    comment_4:     NOT AVAILABLE SELECT SECONDARY TARGET
    comment_5:     HD122451.  TIME CRITICAL EPOCH IS A
    comment_6:     DUMMY.  SEE IMPLEMENTATION PLAN.

!

    linenum:       203.000
    sequence_1:    USE
    sequence_2:    STARPIX
    targname:      PSEUDOTARG2
    req_1:         SEQ 201-202 WITHIN 4.5H;
    req_2:         COND IF HD48915 NOT AVAILABLE;
    req_3:         AT JD2450633.5 +/- 0.01D;
    comment_1:     CRITICAL TIMING MUST BE ENFORCED.
    comment_2:     SECONDARY TARGET IS BETA-CEN/HD122451.
    comment_3:     SCHEDULE ONLY IF PRIMARY TARGET IS
    comment_4:     NOT AVAILABLE.

!
! end of exposure logsheet

! No scan data records found