! Proposal 6692, submission 1
! PI: Lotfi Ben Jaffel
! Received Fri Feb 16 05:09:04 EST 1996
! From: lotfi@iap.fr
! Subject: 6692.prop
! Hubble Space Telescope Cycle 6 (1996) Phase II Proposal Template
! $Id: 6692,v 8.1 1996/06/17 14:43:29 pepsa Exp $
! Hubble Space Telescope Cycle 6 (1996) Phase II Proposal Template
! $Id: 6692,v 8.1 1996/06/17 14:43:29 pepsa Exp $
!
!   Refer to the HST Phase II Proposal Instructions to fill this out
!
!   Anything after a "!" is ignored, and may be deleted
!
!   All keywords with multiple entries are comma delimited except the
!   Visit_Requirements and Special_Requirements keywords which can be
!   delimited with carriage returns or semi-colons, but not commas
!
! For help call your Program Coordinator: Manning
!             Phone: 410-338-4456    , E-mail: manning@stsci.edu
!
! This partially completed template was generated from a Phase I proposal.
! Name of Phase I Proposal: archive-0772.ben_jaffel.prop
! Date generated: Fri Dec 22 16:55:11 EST 1995
!

Proposal_Information                           ! Section 4
              Title:  The abundance and distribution of deuterium on Saturn
  Proposal_Category:  GO
Scientific_Category:  SOLAR SYSTEM
             Cycle:    6

Investigators
     PI_name:         Lotfi Ben Jaffel
     PI_Institution:  Institut d'Astrophysique de Paris

          CoI_Name:   Darrell Strobel
   CoI_Institution:   Johns Hopkins University
           Contact:             ! Y or N (designate at most one contact)

          CoI_Name:   Randall Gladstone
   CoI_Institution:   Southwest Research Institute
           Contact:             ! Y or N (designate at most one contact)

          CoI_Name:   Alfred Vidal-Madjar
   CoI_Institution:   Institut d'Astrophysique de Paris
           Contact:             ! Y or N (designate at most one contact)

          CoI_Name:   Paul Feldman
   CoI_Institution:   Johns Hopkins University
           Contact:             ! Y or N (designate at most one contact)

          CoI_Name:   Warren Moos
   CoI_Institution:   Johns Hopkins University
           Contact:             ! Y or N (designate at most one contact)

          CoI_Name:   Claude Emerich
   CoI_Institution:   Institut d'Astrophysique Spatiale
           Contact:             ! Y or N (designate at most one contact)

          CoI_Name:   John Clarke
   CoI_Institution:   University of Michigan
           Contact:             ! Y or N (designate at most one contact)


Abstract:                                ! Free format text (please update)
    We propose to obtain high resolution profiles of the D Lyman
    alpha line emitted by the limb of the upper atmosphere Saturn,  
    using the GHRS Echelle A and the LSA. Our
    technique consists in a radial drift of the LSA slit across
    the limb of the planet. This is much like the very efficient
    occultation technique although we record reflected instead of
    transmitted light. As the deuterium emission is optically
    thin, the analysis of the resulting profiles will provide,
    through our photochemistry models and radiative transfer
    calculations, the possibility for the first time to retrieve
    the deuterium scale height and abundance at least in four locations 
    of the upper atmosphere of Saturn. Scale heights at different 
    locations derived from the D Ly-alpha emission, and the analysis of the 
    H Ly-alpha profile, obtained with each limb observation, will accurately
    provide the H total column density. A precise estimate of the
    D/H ratio will therefore be inferred. Recently, we
    successfully applied the technique to observe the limb of
    Jupiter with the medium resolution grating G160M. The inferred
    D/H ratio ~ 6+/- 1 * 10^-5 seems to support the measurements
    made through HD/H2 rather than CH3D/CH4. The uncertainty on
    this value could be reduced if high resolution observations
    with Echelle A are conducted. This should confirm the newly
    derived ratio and check the D/H ratio for Saturn.
    Ultimately, this will help to refine the scenario on the
    formation and the evolution our Solar System 4.5 billions
    years ago.

Questions                       ! Free format text (please update)

     Observing_Description:
         1. A new technique of observation, On the basis of
         the available estimates of the H total content and the D/H
         ratio, one can readily show that the D Ly-alpha line is
         optically thin and that the Saturn planetary disk
         averaged D Ly-alpha emissions cannot exceed few tens Rayleigh. 
         We propose a new technique of observation with the
         side one echelle to derive the deuterium abundance and scale
         height at least at four locations in the upper atmosphere of
         the planet. For instance, let's consider, from
         a theoretical point of view, the situation where the LSA is
         100\% filled by the bright limb as depicted in Fig. 2.a. We
         also consider an atmospheric model where the deuterium
         constituent extends between the CH4 absorbing
         level (located say at R_0) and an upper level (located say at
         Rmax). Ignoring for the moment the H Ly-alpha emission, one
         should obtain for the Ech-A resolution, a D Ly-alpha line
         profile as depicted in Fig. 2.b. Here appears the strength of
         GHRS. Because the line is optically thin, for each position
         of the slit across the limb, there is a direct correspondence
         between each 0.22" spatial region in the dispersion direction
         and each of the eight diodes on which the LSA projects. The
         result is that the spatial limb variation is directly
         converted into clear and simple spectral variation from the
         blue to the red wing of the line (see Fig. 2.b,c). Indeed,
         the line being optically thin, it is not difficult to show
         that the D Ly-alpha line intensity can be approximatively
         written as follows:, I_D = sum\limits_i=1^8 J_i* w_i  where
         w_i=(n_0.H_0+n_1.H_1)/(2.cos(Psi_i)) with i=1,5, 
         w_6=2*(n_0.H_0)/(2.cos(Psi_6)) (the path is double for that
         position), w_7=2*(n_1.H_1)/(2.cos(Psi_7)),
         w_8=2*(n_2.H_1)/(2.cos(Psi_8)), with Psi_1 to Psi_8 the
         observing angles, and where n_0, n_1, and n_2 are the
         deuterium number densities at respectively R_0, R_1, and R_2.
         J_1 to J_8 are each of the eight 0.22" region contribution to
         the total signal. For a seek of clarity, we consider the
         simple case where only the D scale height H_0 for the layer
         embedded between R_0 and R_1 is different from H_1 the D
         scale height for the region above R_1. Comparison between
         theoretical models and observation will surely provide at
         least the three quantities D_0 = (n_0.H_0+n_1.H_1),
         D_1=n_1.H_1, and D_2=n_2.H_1 corresponding respectively to
         the deuterium total column density, column density between
         R_1 and R_2, and between R_2 and Rmax. Considering an
         exponential variation for the D number density, it is
         straightforward to show that:,  H_0 = (R_1-R_0)/ln( (D_0 -
         D_1)/D_1), H_1 = (R_2-R_1)/ln( D_2/D_1),  n_0 = (D_0 -
         D_1)/H_0,   n_1 = D_1/H_1,   and    n_2 = D_2/H_1., Observing
         with LSA and Echelle A will provide for a thin line a signal
         extending over 8 diodes which may help to derive at least 4
         parameters of the model. When using Ech-A, the isotopic D-H
         spectral separation (~ 80  km/s) is large enough to avoid
         contamination from the planet's H Ly-alpha line and the Earth
         geocorona. For Jupiter, the H Ly-alpha intensity at mid-
         latitude from recent GHRS data is ~ 8 kR  (Clarke et al., ApJ
         Lett., 430, L76  1994), and the Earth geocoronal emission is
         ~ 2-3 kR during dark time. We expect a 2.5 kR D Ly-alpha line
         due to the limb brightening. Observing the approaching limb
         will enhance even more the D Ly-alpha emission as the
         incident solar D Ly-alpha photons are blue-shifted placing
         the deuterium resonance close to the solar Ly-alpha blue
         emission peak. This will enhance by nearly a factor 2 the
         planet's D Ly-alpha line. Using the limited resolving
         power of the HRS/G160M grating, the technique showed to be
         very efficient even observing the dark approaching limb of
         Jupiter as shown in Fig.3. The case of Saturn is somewhat more
         complicated due to the absorption by the interplanetary
         medium that separates the planet from Earth. During cycle 6,
         we will have solar activity not too far from minimum
         conditions, so that, after correction for the IPM absorption,
         the Saturn H Ly-alpha emission will not exceed 1 to 2 kR
         (integrated over the entire disk). Recent observations we
         made, using IUE (Prange et al., IUE program 1991) and the
         GHRS (Clarke et al., program ID 2556), revealed a 1.5 kR to 2
         kR brightness. Near 1996 observational conditions, the
         interplanetary medium will absorb in the red wing of the H Ly
         -alpha line very far from the D Ly-alpha resonance wavelength
         (the H-D lines separation is 80 km/s). It follows that the D
         Ly-alpha line will not be disturbed by the IPM. Considering a
         ratio D/H = 1.7* 10^-5 (Noll and Larson, 1991), we derive for
         Saturn a sunlit limb emission at D Ly-alpha of 500 to 700
         Rayleighs which corresponds to a disk integrated intensity of
         50 to 70 R., 
 
 2. Technical description of the observations,

         We propose to point the approaching limb as a reference
         target as depicted in Fig. 2a. To accurately locate the Ly-
         alpha planet's limb, we use the procedure proposed by the STI
         Moving Target Programs team for extended targets. We thus
         propose to use the Onboard HRS acquisition to locate the
         Saturnian satellite Rhea, shift to Saturn, and get the planetary
         limb. This will lead to a total error on the limb location of 
         0.1 arc-sec. These estimates have been derived by K. Noll based on
         already completed programs. The problem with the last
         acquisition technique is that the planetary Ly-alpha limb is
         not accurately defined. To handle this difficulty, we use a
         well known atmospheric level (the 1 bar level, and estimate 
         the distance between the two planetary limbs through our radiative
         transfer calculation. From our analysis, we derived that this
         distance is known with an error of +/- 150 km. This corresponds 
         0.03 arc-sec for Saturn. Given the ~ 2
         arc-sec LSA width, we are sure to get the planet's Ly-alpha
         limb within the LSA field of view with an error smaller than
         0.12 arc-sec. The whole technique previously presented
         has been successfully used for cycle 3 observation of Jupiter
         and there are no inherent obstacles  (Ben Jaffel et al.,
         1994). We therefore require 9 dark orbits, 7
         for the LSA position across the expected planetary limb, and
         the last 2 orbits for sky background. The approaching limb is
         selected. 
         The ORIENTATION of the Telescope for planetary
         targets is bimodal. Before opposition the orientation of the
         U3 axis from the North is approximatively 270 degrees, and
         after opposition it is approximatively 90 degrees. Based on
         this, the position angle of the spin axis of Saturn, and
         the orientation of the GHRS aperture, it is possible to
         determine what position on the disk perimeter to point at to
         align the aperture Y axis parallel to the planetary limb. Therefore, 
         our observation will not really constrain the spacecraft operation, 
         but will use the default orientation instead. However, to ensure any 
         departure from the nominal angle used to determine the planetary 
         limb, we include an ORIENT constraint, though it corresponds to the 
         expected orientation of the spacecraft.
 3. Time exposures calculation  
       1 kR at 1216 Angstrom within a 2"*  0.25" solid angle (one of our
       spatial-spectral bin) roughly corresponds to 1.53* 10^-14 ergs/cm^2-sec.
       We expect the D Ly-alpha line to be ~ 0.04 Angstrom large which
       gives a peak level of 3.83* 10^-13 ergs/cm^2-sec-Angstrom.
       For Echelle A and LSA the sensitivity at 1216 Angstrom is ~
       0.87* 10^11 (counts/sec-diode)/(erg/cm^2-sec-Angstrom). It
       follows that for 1 kR we expect a peak rate of roughly 0.031
       counts/sec-diode. For a 60 min integration time, we derived a
       signal to noise S/N > 10 per kR per spectral bin i.e. S/N >
       28 per kR for the  LSA.

   Real_Time_Justification:

         We desire to obtain the maximum doppler shift between the
         planetary and geocoronal emissions, and if possible to minimize 
         the geocoronal background Ly-alpha emission. This is accomplished 
         using the Earth motion, and observing Saturn no later than 
         July 31, 1996. Also, from our 
         experience using the HST/GHRS during the last years, we stress out 
         the importance to measure the sky-background signal in the same 
         conditions of observation (same range of the targets zenith angles 
         and sun zenith angles) than the planet. This means that the 
         sky-background and the planet's observations should be simultaneous 
         and starting with the same position of HST on its orbit.
          


   Calibration_Justification:     ! from Real_Time_Justification

         As we request to acquire the limb of Saturn from the acquisition 
         of its satellite Rhea, we request a WAVE exposure at the beginning of 
         the observation of Saturn. The WAVE should be recorded on the same 
         position of the carrousel as when starting the planetary observation.
         It is intended to monitor wavelength drifts. We ask a WAVE for each 
         exposure. Indeed, given the particular geometry of observation, we 
         cannot use the H Ly-alpha center line as a reference. Moreover, 
         Doppler shifts induced by thermospheric wind may occur and we would 
         like to avoid the confusing situation where a wavelength drift may 
         be interpreted as a real Doppler shift. As we request our own wave 
         calibration, no SPYBAL is necessary.

      Additional_Comments: The success of this program is completely based on 
         the following conditions :
         - At the time of observation, the Y axis of LSA should be parallel to 
           the approaching limb of the planet. The latitude of the
           only region that satisfy that condition is equal to : 
                LATITUDE  = 225D - (HST/Roll angle)
           with a corresponding radius RAD = 59438 + 3929*(COS(LAT))**2
         - The doppler shift between Saturn and Earth lines should be maximum 
           in order to not affect the weak H and D lyman-alpha lines of
           Saturn. This is accomplished by observing Saturn before July 31 1996.

Solar_System_Targets                    ! Section 5.2
  Target_Number:1
    Target_Name:Rhea-Acquisition
    Description:Satellite Rhea
        Level_1:STD=Saturn        
        Level_2:STD=Rhea                       ! Satellite of Level_1
         Window:SEP OF Rhea Saturn FROM Earth LT 60" 
                SEP OF Rhea Saturn FROM Earth GT 30" 
                SEP OF RHEA TETHYS FROM EARTH GT 10" 
                SEP OF RHEA DIONE FROM EARTH GT 10"       
                SEP OF RHEA MIMAS FROM EARTH GT 10" 
                SEP OF RHEA TITAN FROM EARTH GT 10" 
                SEP OF RHEA ENCELADUS FROM EARTH GT 10"
           Flux:V=9.7 
                B-V=0.78                     ! Include at least V and B-V
       Comments:HRS ACQUISITION OF RHEA FOR PEAKUP ON SATELLITE CENTER. 
                LSA IS REQUIRED. FIRST STEP OF THE TECHNIQUE TO ACCURATELY 
                ACQUIRE THE LIMB OF SATURN DESCRIBED IN TARGNUM 2,3

  Target_Number:2
    Target_Name:SATURN-LIMB
    Description:FEATURE SATURN
        Level_1:STD=SATURN    
        Level_2:TYPE = TORUS, LONG = 270,
                LAT = -22, RAD = 64534.,
                POLE_LAT = 90                     
           Flux:SURF(V)=7.0
                SURF-LINE(1216) = 2 +/- 1 E-13
                W-LINE(1216) = 0.04 +/- 0.02
                
       Comments:THE APPROACHING LIMB IS REQUIRED. 
                IF, AT THE DATE OF OBSERVATION, THE HST ROLL ANGLE CHANGES, 
                PLEASE CHANGE THE LATITUDE AND THE RADIUS AS FOLLOWS :
                LAT  = 225 D - ROLL ; RAD (KM) = 59438 + 5929*(COS(LAT))**2
                IN ORDER TO ALWAYS HAVE THE Y AXIS OF LSA // TO THE LIMB

  Target_Number:3
    Target_Name:SKY-BACKGROUND
    Description:OFFSET SATURN
        Level_1:STD=SATURN    
        Level_2:TYPE = TORUS, LONG = 270,
                LAT = -22, RAD = 12000000.,
                POLE_LAT = 90                     
           Flux:SURF-LINE(1216) = 10 +/- 5 E-13
                W-LINE(1216) = 0.1 +/- 0.02               
       Comments:SKY BACKGROUND ROUGHLY 3 ARCMIN OFF SATURN.
                PLEASE SCHEDULE IMMEDIATELY AFTER SATURN OBSERVATION 
                IN ORDER TO AVOID SOLAR FLUX VARIATION AT 1216 A.
                THE SKY OBSERVATION SHOULD START WITH HST IN THE SAME 
                POSITION ON ITS ORBIT AS FOR THE PLANETARY OBSERVATION.

! This is a template for a single visit containing a single exposure
! Repeat exposure and visit blocks as needed

Visits                                  ! Section 6
      Visit_Number:1
Visit_Requirements:GUIDing TOLerance 0.13"                    ! Section 7.1
                   ORIENTation 246D TO 248D
                   BETWEEN 1-JUL-96 AND 31-JUL-96
                   SEQ 1-2 WITHIN 48H

    Visit_Comments:THE ORIENT REQUIREMENT ABOVE IS NOT A CONSTRAINT. 
                   WE NEED TO CONSTRAIN THE LATITUDE FOR WHICH THE 
                   Y AXIS OF THE LSA IS PARALLEL TO THE PLANETARY APPROACHING 
                   LIMB. THIS LATITUDE IS DEFINED BY : LAT = 225D - ROLL 
                   AND  RAD (KM) = 58438 + 5929*(COS(LAT))**2 
                   WE RECOMMAND TO USE THE DEFAULT ROLL BUT TO MODIFY 
                   THE PLANETARY LAT ACCORDING TO THE FORMULAS PROVIDED ABOVE; 
                   Visit should be completed in SEVEN consecutive orbits.

     Exposure_Number:10                  ! Section 6.5
         Target_Name:RHEA-ACQUISITION
              Config:HRS
              Opmode:ACQ
            Aperture:2.0
          Sp_Element:MIRROR-N2
          Wavelength:
 Optional_Parameters:BRIGHT=RETURN,LOCATE=EXTENDED                     
Number_of_Iterations:1
   Time_Per_Exposure:18S
Special_Requirements:ONBOARD ACQ FOR 20              ! Section 7.2
            Comments:STEP-TIME=2.0 sec

     Exposure_Number:20                  ! Section 6.5
         Target_Name:RHEA-ACQUISITION
              Config:HRS
              Opmode:ACQ/PEAKUP
            Aperture:2.0
          Sp_Element:MIRROR-N2
          Wavelength:
 Optional_Parameters:EXTENDED=YES
Number_of_Iterations:1
   Time_Per_Exposure:204S
Special_Requirements:ONBOARD ACQ FOR 25-81   
            Comments:step-time= 2.0 sec 

     Exposure_Number:25                  ! Section 6.5
         Target_Name:SATURN-LIMB
              Config:HRS
              Opmode:IMAGE
            Aperture:2.0
          Sp_Element:MIRROR-N2
          Wavelength:
 Optional_Parameters:precision=high
Number_of_Iterations:1                
   Time_Per_Exposure:51.2S  
Special_Requirements:SEQ 20-26 NON-INT
            comments:STEP-TIME=0.2 

     Exposure_Number:26                  ! Section 6.5
         Target_Name:SATURN-LIMB
              Config:HRS
              Opmode:ACCUM
            Aperture:2.0
          Sp_Element:G160M
          Wavelength:1216
 Optional_Parameters:FP-SPLIT = STD,STEP-PATT= DEF,
                     DOPPLER=DEF,COMB=FOUR
Number_of_Iterations:1                
   Time_Per_Exposure:326.4S
Special_Requirements: 
            comments: 

     Exposure_Number:30                 ! Section 6.5
         Target_Name:WAVE 
              Config:HRS 
              Opmode:ACCUM 
            Aperture:SC2 
          Sp_Element:ECH-A 
          Wavelength:1216 
 Optional_Parameters:
Number_of_Iterations:1 
   Time_Per_Exposure:54.4S 
Special_Requirements:SEQ 30-33 NON-INT
            Comments:WAVE CALIBRATION FOR EXPOSURE 31.

     Exposure_Number:31                  ! Section 6.5
         Target_Name:SATURN-LIMB 
              Config:HRS 
              Opmode:ACCUM 
            Aperture:2.0 
          Sp_Element:ECH-A 
          Wavelength:1216 
 Optional_Parameters:FP-SPLIT = STD,STEP-PATT= DEF,
                     DOPPLER=DEF,COMB=FOUR,SPYBAL=NO
Number_of_Iterations:1              
   Time_Per_Exposure:761.6S 
Special_Requirements: 
            Comments:Please start on same position of 
                     carrousel used for wave 30.

      Exposure_Number:32                 ! Section 6.5
         Target_Name:WAVE 
              Config:HRS 
              Opmode:ACCUM 
            Aperture:SC2 
          Sp_Element:ECH-A 
          Wavelength:1216 
 Optional_Parameters:
Number_of_Iterations:1 
   Time_Per_Exposure:54.4S 
Special_Requirements:
            Comments:WAVE CALIBRATION FOR EXPOSURE 33.

     Exposure_Number:33                 ! Section 6.5
         Target_Name:SATURN-LIMB 
              Config:HRS 
              Opmode:ACCUM 
            Aperture:2.0 
          Sp_Element:ECH-A 
          Wavelength:1216 
 Optional_Parameters:FP-SPLIT = STD,STEP-PATT= DEF,
                     DOPPLER=DEF,COMB=FOUR,SPYBAL=NO
Number_of_Iterations:1             
   Time_Per_Exposure:652.8S  
Special_Requirements:
            Comments:Please start on same position of 
                     carrousel used for wave 32.


     Exposure_Number:40                 ! Section 6.5
         Target_Name:WAVE 
              Config:HRS 
              Opmode:ACCUM 
            Aperture:SC2 
          Sp_Element:ECH-A 
          Wavelength:1216 
 Optional_Parameters:
Number_of_Iterations:1 
   Time_Per_Exposure:54.4S 
Special_Requirements:SEQ 40-43 NON-INT
            Comments:WAVE CALIBRATION FOR EXPOSURE 41.

     Exposure_Number:41                  ! Section 6.5
         Target_Name:SATURN-LIMB 
              Config:HRS 
              Opmode:ACCUM 
            Aperture:2.0 
          Sp_Element:ECH-A 
          Wavelength:1216
 Optional_Parameters:FP-SPLIT = STD,STEP-PATT= DEF,
                     DOPPLER=DEF,COMB=FOUR,SPYBAL=NO
Number_of_Iterations:1              
   Time_Per_Exposure:761.6S 
Special_Requirements: 
            Comments:Please start on same position of 
                     carrousel used for wave 40.


     Exposure_Number:42                 ! Section 6.5
         Target_Name:WAVE 
              Config:HRS 
              Opmode:ACCUM 
            Aperture:SC2 
          Sp_Element:ECH-A 
          Wavelength:1216 
 Optional_Parameters:
Number_of_Iterations:1 
   Time_Per_Exposure:54.4S 
Special_Requirements:
            Comments:WAVE CALIBRATION FOR EXPOSURE 43.

     Exposure_Number:43                 ! Section 6.5
         Target_Name:SATURN-LIMB 
              Config:HRS 
              Opmode:ACCUM 
            Aperture:2.0 
          Sp_Element:ECH-A 
          Wavelength:1216 
 Optional_Parameters:FP-SPLIT = STD,STEP-PATT= DEF,
                     DOPPLER=DEF,COMB=FOUR,SPYBAL=NO
Number_of_Iterations:1             
   Time_Per_Exposure:652.8S 
Special_Requirements:
            Comments:Please start on same position of 
                     carrousel used for wave 42.


     Exposure_Number:50                 ! Section 6.5
         Target_Name:WAVE 
              Config:HRS 
              Opmode:ACCUM 
            Aperture:SC2 
          Sp_Element:ECH-A 
          Wavelength:1216 
 Optional_Parameters:
Number_of_Iterations:1
   Time_Per_Exposure:54.4S 
Special_Requirements:SEQ 50-53 NON-INT
            Comments:WAVE CALIBRATION FOR EXPOSURE 51.

     Exposure_Number:51                  ! Section 6.5
         Target_Name:SATURN-LIMB 
              Config:HRS 
              Opmode:ACCUM 
            Aperture:2.0 
          Sp_Element:ECH-A 
          Wavelength:1216 
 Optional_Parameters:FP-SPLIT = STD,STEP-PATT= DEF,
                     DOPPLER=DEF,COMB=FOUR,SPYBAL=NO
Number_of_Iterations:1              
   Time_Per_Exposure:761.6S
Special_Requirements: 
            Comments:Please start on same position of 
                     carrousel used for wave 50.


     Exposure_Number:52                 ! Section 6.5
         Target_Name:WAVE 
              Config:HRS 
              Opmode:ACCUM 
            Aperture:SC2 
          Sp_Element:ECH-A 
          Wavelength:1216 
 Optional_Parameters:
Number_of_Iterations:1
   Time_Per_Exposure:54.4S 
Special_Requirements:
            Comments:WAVE CALIBRATION FOR EXPOSURE 53.

     Exposure_Number:53                  ! Section 6.5
         Target_Name:SATURN-LIMB 
              Config:HRS 
              Opmode:ACCUM 
            Aperture:2.0 
          Sp_Element:ECH-A 
          Wavelength:1216 
 Optional_Parameters:FP-SPLIT = STD,STEP-PATT= DEF,
                     DOPPLER=DEF,COMB=FOUR,SPYBAL=NO
Number_of_Iterations:1               
   Time_Per_Exposure:652.8S
Special_Requirements: 
            Comments:Please start on same position of 
                     carrousel used for wave 52.


     Exposure_Number:60                 ! Section 6.5
         Target_Name:WAVE 
              Config:HRS 
              Opmode:ACCUM 
            Aperture:SC2 
          Sp_Element:ECH-A 
          Wavelength:1216 
 Optional_Parameters:
Number_of_Iterations:1 
   Time_Per_Exposure:54.4S 
Special_Requirements:SEQ 60-63 NON-INT
            Comments:WAVE CALIBRATION FOR EXPOSURE 61.

     Exposure_Number:61                  ! Section 6.5
         Target_Name:SATURN-LIMB 
              Config:HRS 
              Opmode:ACCUM 
            Aperture:2.0 
          Sp_Element:ECH-A 
          Wavelength:1216 
 Optional_Parameters:FP-SPLIT = STD,STEP-PATT= DEF,
                     DOPPLER=DEF,COMB=FOUR,SPYBAL=NO
Number_of_Iterations:1           
   Time_Per_Exposure:761.6S 
Special_Requirements: 
            Comments:Please start on same position of 
                     carrousel used for wave 60.


     Exposure_Number:62                 ! Section 6.5
         Target_Name:WAVE 
              Config:HRS 
              Opmode:ACCUM 
            Aperture:SC2 
          Sp_Element:ECH-A 
          Wavelength:1216 
 Optional_Parameters:
Number_of_Iterations:1 
   Time_Per_Exposure:54.4S 
Special_Requirements:
            Comments:WAVE CALIBRATION FOR EXPOSURE 63.

     Exposure_Number:63                 ! Section 6.5
         Target_Name:SATURN-LIMB 
              Config:HRS 
              Opmode:ACCUM 
            Aperture:2.0 
          Sp_Element:ECH-A 
          Wavelength:1216 
 Optional_Parameters:FP-SPLIT = STD,STEP-PATT= DEF,
                     DOPPLER=DEF,COMB=FOUR,SPYBAL=NO
Number_of_Iterations:1            
   Time_Per_Exposure:652.8S 
Special_Requirements: 
            Comments:Please start on same position of 
                     carrousel used for wave 62.


     Exposure_Number:70                 ! Section 6.5
         Target_Name:WAVE 
              Config:HRS 
              Opmode:ACCUM 
            Aperture:SC2 
          Sp_Element:ECH-A 
          Wavelength:1216 
 Optional_Parameters:
Number_of_Iterations:1 
   Time_Per_Exposure:54.4S 
Special_Requirements:SEQ 70-71 NON-INT
            Comments:WAVE CALIBRATION FOR EXPOSURE 81.

     Exposure_Number:71                  ! Section 6.5
         Target_Name:SATURN-LIMB 
              Config:HRS 
              Opmode:ACCUM 
            Aperture:2.0 
          Sp_Element:ECH-A 
          Wavelength:1216 
 Optional_Parameters:FP-SPLIT = STD,STEP-PATT= DEF,
                     DOPPLER=DEF,COMB=FOUR,SPYBAL=NO
Number_of_Iterations:1              
   Time_Per_Exposure:1414.4S 
Special_Requirements: 
            Comments:Please start on same position of 
                     carrousel used for wave 70.


     Exposure_Number:80                 ! Section 6.5
         Target_Name:WAVE 
              Config:HRS 
              Opmode:ACCUM 
            Aperture:SC2 
          Sp_Element:ECH-A 
          Wavelength:1216 
 Optional_Parameters:
Number_of_Iterations:1 
   Time_Per_Exposure:54.4S 
Special_Requirements:SEQ 80-81 NON-INT
            Comments:WAVE CALIBRATION FOR EXPOSURE 81.

     Exposure_Number:81                  ! Section 6.5
         Target_Name:SATURN-LIMB 
              Config:HRS 
              Opmode:ACCUM 
            Aperture:2.0 
          Sp_Element:ECH-A 
          Wavelength:1216 
 Optional_Parameters:FP-SPLIT = STD,STEP-PATT= DEF,
                     DOPPLER=DEF,COMB=FOUR,SPYBAL=NO
Number_of_Iterations:1      
   Time_Per_Exposure:1414.4S 
Special_Requirements: 
            Comments:Please start on same position of 
                     carrousel used for wave 80.



Visits                                  ! Section 6
      Visit_Number:2
Visit_Requirements:GUIDing TOLerance 0.13" 
                   ORIENTation 246D TO 248D
                   BETWEEN 1-JUL-96 AND 31-JUL-96
                   SEQ 1-2 WITHIN 48H
    Visit_Comments:The main reason to have the observations within 48H
                   is to avoid lyman-alpha solar flux variation (particularly 
                   the solar line shape) that could be catastrophic for the 
                   isotopic D/H ratio.

     Exposure_Number:14                 ! Section 6.5
         Target_Name:RHEA-ACQUISITION
              Config:HRS
              Opmode:ACQ
            Aperture:2.0
          Sp_Element:MIRROR-N2
          Wavelength:
 Optional_Parameters:BRIGHT=RETURN,LOCATE=EXTENDED                     
Number_of_Iterations:1
   Time_Per_Exposure:18S
Special_Requirements:ONBOARD ACQ FOR 15              ! Section 7.2
            Comments:STEP-TIME=2.0 sec


     Exposure_Number:15                  ! Section 6.5
         Target_Name:RHEA-ACQUISITION
              Config:HRS
              Opmode:ACQ/PEAKUP
            Aperture:2.0
          Sp_Element:MIRROR-N2
          Wavelength:
 Optional_Parameters:EXTENDED=YES
Number_of_Iterations:1
   Time_Per_Exposure:204S
Special_Requirements:ONBOARD ACQ FOR 16-19   
            Comments:step-time= 2.0 sec 


     Exposure_Number:16                  ! Section 6.5
         Target_Name:SATURN-LIMB
              Config:HRS
              Opmode:IMAGE
            Aperture:2.0
          Sp_Element:MIRROR-N2
          Wavelength:
 Optional_Parameters:precision=high
Number_of_Iterations:1                
   Time_Per_Exposure:51.2S  
Special_Requirements:SEQ 16-17 NON-INT
            comments:STEP-TIME=0.2 

     Exposure_Number:17                  ! Section 6.5
         Target_Name:SATURN-LIMB
              Config:HRS
              Opmode:ACCUM
            Aperture:2.0
          Sp_Element:G160M
          Wavelength:1216
 Optional_Parameters:FP-SPLIT = STD,STEP-PATT= DEF,
                     DOPPLER=DEF,COMB=FOUR
Number_of_Iterations:1                
   Time_Per_Exposure:326.4S
Special_Requirements: 
            comments:

     Exposure_Number:18                  ! Section 6.5
         Target_Name:WAVE
              Config:HRS
              Opmode:ACCUM
            Aperture:SC2
          Sp_Element:ECH-A
          Wavelength:1216
 Optional_Parameters:
Number_of_Iterations:1
   Time_Per_Exposure:54.4S
Special_Requirements:SEQ 18-19 NON-INT
            Comments:WAVE CALIBRATION FOR SKY-BACKGROUND 19.

     Exposure_Number:19                  ! Section 6.5
         Target_Name:SKY-BACKGROUND 
              Config:HRS 
              Opmode:ACCUM 
            Aperture:2.0 
          Sp_Element:ECH-A 
          Wavelength:1216 
 Optional_Parameters:FP-SPLIT = STD, STEP-PATT= DEF,
                     DOPPLER=DEF,COMB=FOUR,SPYBAL=NO
Number_of_Iterations:1
   Time_Per_Exposure:761.6S 
Special_Requirements:
             Comments:Please start on same position of 
                     carrousel used for wave 18.

     Exposure_Number:20                  ! Section 6.5
         Target_Name:WAVE
              Config:HRS
              Opmode:ACCUM
            Aperture:SC2
          Sp_Element:ECH-A
          Wavelength:1216
 Optional_Parameters:
Number_of_Iterations:1
   Time_Per_Exposure:54.4S
Special_Requirements:SEQ 20-21 NON-INT
            Comments:WAVE CALIBRATION FOR SKY-BACKGROUND 19.

     Exposure_Number:21                  ! Section 6.5
         Target_Name:SKY-BACKGROUND 
              Config:HRS 
              Opmode:ACCUM 
            Aperture:2.0 
          Sp_Element:ECH-A 
          Wavelength:1216 
 Optional_Parameters:FP-SPLIT = STD, STEP-PATT= DEF,
                     DOPPLER=DEF,COMB=FOUR,SPYBAL=NO
Number_of_Iterations:1
   Time_Per_Exposure:761.6S 
Special_Requirements:
             Comments:Please start on same position of 
                     carrousel used for wave 18.




Data_Distribution                       ! Defaults indicated; change if desired

         Medium:        8MM             ! 8MM or 6250BPI or 1600BPI
Blocking_Factor:        10              ! 10 or 1
                                        ! Only astronomers with very old 9-
                                        ! track tape drives should consider
                                        ! a blocking factor of 1

        Ship_To:   PI_Address           ! STSCI or PI_Address or <free-text>
                                        ! PI Address from Phase I is:
                                        !
                                                 !  98bis Boulevard Arago
                                                 !  Paris
                                                 !  F-75014
                                        !
                                        !
       Ship_Via:        UPS             ! UPS (2-day) or OVERNIGHT
                                        ! Overnight shipping done at PI expense

Recipient_Email:                        ! Needed if Ship_To: is not PI_Address
                                        ! <free-text>

! Let us know what you think of this template and software!
! Please send a list of your likes and dislikes to your Program Coordinator __Diagnostic-Sum-Section__
Software-Version (Controller= 6.0)
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Transformation (Errors= 0 Fatal-Errors= 0 )
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