ROSAT S/C Status 1998-08-31 ... 1998-12-03

Compiled by Jakob Englhauser
.. HOME .. Up ..
Mon 1998-08-31 (DoY 243)

     No safemode up to this point.

  04:32:15   WHM6  still not in safemode.
                     (300598 is in Earth block during Weilheim)

  05:06:15   ----  slew to 202805
  06:43:00   ----  return to nominal timeline

  09:16:25   WPS   several periods of steady and transient state
                     (probably since the contact started only a few minutes
                      after the ROSAT night)

  14:30      AGO   SAA throughout the contact (no X-ray data);
                     observed timeline events:
                       1) Earth block (transient)
                       2) no Earth block (transient, and steady)
                       3) update of actual quaternion
                       4) slew to new target at the end of the contact

  20:08:30   WHM1  still ok; first transient (as expected for ROSAT night),
                   then Earth block


Tue 1998-09-01 (DoY 244)

  23:24:45   WHM3  complete recovery of WFC (from scratch)
  01:04:45  +WHM4   - all error messages of WFC (as seen since 1998-Apr)
                        disappeared
                    - WFC is observing again (HV on)
                    - accidentally the 'AMCS Restart of STCW' was disabled
                        (resets of STCW by AMCS are disabled)

  07:30      WPS   enable 'AMCS Restart of STCW'
                     satellite went steady shortly afterwards

  14:15      AGO   ok.

  (author on vacation until 1998-09-14)

Wed 1998-09-02 (DoY 245)


  14:05      AGO   again safemode (but not in previous contacts) (S28)

  Next possibility for recovery:

Thu 1998-09-03 (DoY 246)

  14:05      AGO   ? recovery



  ...



Thu 1998-09-10 (DoY 253)
Fri 1998-09-11 (DoY 254)

  Tests of updated AMCS software at spacecraft simulator at GSOC


Mon 1998-09-14 (DoY 257)

  (author back from vacation)

  ROSAT is observing according to the timeline.

  14:55:00   WHM1  ok; transient at the beginning, steady at the end of the contact

  16:30:30   WHM2  safemode; recovery started

  19:49:45   WHM4  HRI back in focus, and working


Tue 1998-09-15 (DoY 258)

  ROSAT is observing according to the timeline.

  14:45:15   WHM1  ok; steady throughout the contact
  16:22:00   WHM2  ok; steady throughout the contact (except for short interrupts)
  18:01:30   WHM3  ok; steady throughout the contact
  19:41:30   WHM4  ok; steady throughout the contact


  There is now a (possible) explanation for one particular type of safemode 
  (CSS3 presence lost after ROSAT night; no return to sun cone possible 
  within the safemode delay time) (LK):

    One of the reaction wheels was close to the saturation threshold
    when the satellite left the ROSAT night. The offset between
    the actual and nominal spin direction was quite big.
    The correction of this situation would have drawn to much current.
    The current request is reduced by a factor of 2 in this case,
    the resulting torque was not sufficient to return to the
    sun cone within the safemode delay time.

    A possible solution is the reduction of the spin around the x axis
    from 20 Nm to 15 Nm (will be commanded soon), to give more margin for
    adjusting the spin after ROSAT nights.


Wed 1998-09-16 (DoY 259)

  ROSAT is still observing according to the timeline
  (end of last contact: 02:13:26).


  Size of Earth block:

    The size of the Earth block assumed by the AMCS will be set to 5 deg
    after the next safemode (currently: 14.5 deg).
    Recent data have shown that stars are tracked and identified far
    beyond the 14.5 deg limit.
    This change enlarges the radius of the CVZ from 8.5 deg to 18 deg
    (a factor of 4.5 square deg in area).
    It is yet unclear whether the X-ray data close to the Earth horizon
    can really be used: increasing distortion (up to 1 deg) of the guide
    star positions has been observed during the ASTROSPAS mission at
    angles less then 10 deg above the Earth horizon.


  The WFC has not been recovered since the safemode on 1998-09-02.
  The reasons were: 
    - frequent safemodes (roughly every other day)
    - bad orbit geometry (Weilheim contacts mainly during ROSAT nights)
    - safety reasons (don't damage WFC by incomplete recovery; 
                      WFC recovery needs 2 Weilheim contacts)


  14:36:00   WHM1  ok; steady throughout the contact
                    - start complete recovery of WFC

  17:53:30   WHM3  recovery of WFC is finished
                    - WFC is observing again (HV on)
                    - AMCS resets of STCW are obviously not accepted by WFC;
                        'AMCS Restart of STCW enable' has not been sent
                          (as on DoY 244)


Thu 1998-09-17 (DoY 260)

  05:16:47   WPS   still ok.

  14:27:15   WHM1  ok.
                    - 'Enable AMCS Restart of STCW' has been commanded
                      consequently: 
                        - update of actual quaternion by more than 2 deg
                        - never steady during the contact (only faint stars
                            in FOV; stars were lost at the end of the contact)

  16:05:15   WHM2  ok; steady throughout the contact.
                    - CSS3 presence threshold set to 7.9 V (previously 7.7 deg)

  17:45:15   WHM3  not very stable: frequent changes between steady and transient

  19:25:00   WHM4  weird data from WFC; WFC was put into safemode
                     recovery during the next Weilheim cycle.


  CSS3 presence threshold:
  CSS1 feedback:


Fri 1998-09-18 (DoY 261)

  05:01:48   GDS   still ok.

  A preliminary analysis of the data of DoY 260 shows that there was 
  practically no acquisition during the time when the 'AMCS Restart of STCW'
  was disabled (1 exception of 3 ks).
  The situation changed as soon as 'AMCS Restart of STCW' was enabled.


  14:18:30   WHM1   ok.
                    - Earth block angle was set to 5 deg (previously 14.5 deg)
                    - recover WFC

  15:57:00   WHM2  transient throughout the contact (no stars present; 
                         due to recovery of WFC?)
                    - reduced value for feedback strength of CSS1 
                        (and CSS3?) information has been sent at the end of the
                        contact.

  16:53:06   ...   Safemode triggered during slew (reason: sun in CSS2)

    GSOC requested two DSN contacts in order to perform a quick recovery
    already during this night (good).

  20:39:28   DSN   start of recovery


Sat 1998-09-19 (DoY 262)

    Successfully recovered. HRI in focus, and switched on.

  12:03:30   ....  Safemode triggered;

  15:48:45   WHM2
  15:48:49      2  start of recovery


Sun 1998-09-20 (DoY 263)

  00:48:00   ....  Safemode triggered during slew (reason: sun in CSS2)


Mon 1998-09-21 (DoY 264)

    Currently in safemode.

    The revised AMCS software will be uploaded and activated during the 
    next Weilheim cycle, if possible.

  15:32:00   WHM2  Upload new AMCS software:
                     - correct derivation of angular velocities
                     - improved defaults for various parameters
                     - angular momentum around x axis reduced from 20 Nm to 15 Nm

  17:12:15   WHM3  Start of recovery

  20:31:30   WHM5  Again in safemode (presumably not due to the new software).


Tue 1998-09-22 (DoY 265)

    Still in safemode.

  12:07:45   WHM1  step 1 of recovery completed.
  13:44:15   WHM2  Again in safemode.

    - Something is wrong (new software? recovery? new parameter settings?).

    - RAM dumps of the new software will be performed during this cycle,
        and compared to the simulator contents of the same region.

    - No further recovery attempts as long as the reason for these safemodes 
        is not understood.

    - Next possibility for recovery: tomorrow afternoon
        (if the problems are understood by then).


Wed 1998-09-23 (DoY 266)

    Still in safemode.

    The safemode of DoY 265 was due to an error during the recovery, 
    and not due to an error in the AMCS software; therefore
    another recovery will be performed today.
    For safety reasons the FI will not be switched on.

  11:58:30   WHM1  Step 1 of recovery (?)
  16:55:30   WHM4  Satellite is steady at the end of the contact.
  18:35:00   WHM5  Not steady throughout the contact (though it should).


Thu 1998-09-24 (DoY 267)

    AMCS is in 'degraded mode'; HRI is still off.


  11:49:30   WHM1  not in safemode; therefore:
                    - move HRI into focus, and switch on.

  16:47:00   WHM4  HRI quick-look screen shows weird image;
                     something is wrong with the HRI!

  18:26:30   WHM5  Continuously steady at the end of the contact.
                   HRI image looks strange; electrical values are ok.
                   Eventually the HRI will be switched off during one of the
                   next contacts.


Fri 1998-09-25 (DoY 268)

    AMCS is in 'safemode'.

    No recovery will be performed until the status of the HRI has been
    clarified.


Mon 1998-09-28 (DoY 271)

    AMCS is in 'safemode'.

    During the next Weilheim Cycle the status of the HRI will be checked.

  11:14:45   WHM1  Perform UV calibration of HRI:
                    - Switch off HRI completely.
                    - Switch on HRI HV.
                    - Perform UV calibration (starting at HV step 6).
                    - Increase HRI voltage step by step up to '14'.
                    - Switch off HRI HV at the end of the contact.


  12:54:00   WHM2  Perform UV calibration of HRI:
                    - Switch on HRI HV.
                    - Perform UV calibration (starting at HV step 6).
                    - Increase HRI voltage step by step up to '15'.
                    - Switch off HRI HV at the end of the contact.


  14:34:00   WHM3  Check X-ray performance of HRI:
                    - Move HRI into focus.
                    - Switch on HRI HV.
                    - Increase HRI voltage step by step up to '14'.
                    - Play around with lower and upper thresholds.
                    - Switch off HRI HV at the end of the contact.
                    - Move HRI off focus.



Tue 1998-09-29 (DoY 272)

    AMCS is in 'safemode'.

    During the next Weilheim Cycle the status checks of the HRI will be continued.

  09:30:30   WHM1  Check X-ray performance of HRI (off focus, i.e. background)
                    - Switch on HRI HV (HV step 14);
                        observe background count rates, esp. valid/invalid ratio.
                    - Play around with LL and UL;
                        observe valid/invalid ratio.
                    - Reduce HRI HV to step 12; observe valid/invalid ratio.
                    - Switch off HRI HV at the end of the contact.

  11:06:15   WHM2  Observe X-ray performance of HRI during WHM contact:
                    - Switch on HRI HV (HV step 14); HRI off focus.
                    - Switch off HRI HV at the end of the contact.


    No more checks today.


Wed 1998-09-30 (DoY 273)

    AMCS is in 'safemode'.

  09:21:00   WHM1  Conditioning (?) of HRI (off focus):
                    - Switch on HRI HV (HV step 14).
                    - Send HRI timeline (HRI master resets).
                    - Set LL=3, UL=0 in order to reduce the HRI countrate
                    - Do NOT switch off HRI HV at the end of the contact.

  10:57:45   WHM2  Conditioning (?) of HRI (continued):
                    - Move HRI into focus.
                    - Set LL=0, UL=3 (default).
                    - Do NOT switch off HRI HV at the end of the contact.
                    - HRI remains in focus.
                    :
                    - Valid (invalid) event rate at 2 (700) cts/s
                        (somehow healed?)
                    - similar behaviour as 1 week ago

  12:37:30   WHM3  like WHM2 (configuration and behaviour of HRI unchanged)

    Operation of the HRI will be continued until the next Weilheim cycle.


Thu 1998-10-01 (DoY 274)

    AMCS is in 'safemode'.
    HRI is operated nominally, and in focus.

    The status of the HRI will be checked by observing Vega (a mere UV source).
    Coordinates (equinox 2000.0):  (R.A.,Dec.) = (279.234 deg, 38.784 deg)
    Current Sun angle: 93.4 deg
    Vega is visible during all Weilheim contacts outside the radiation belts.


  09:11:45   WHM1  HRI:
                    - Turn on UV Calibration;
                        check pattern (esp. if HV overload)
                    - Move HRI to off position.
                   AMCS: step 1 of recovery
                    - careful check of the pointing direction

  10:49:30   WHM2  AMCS: step 2 of recovery: cancelled!
                    - AMCS was put into safemode since it is unclear
                      whether 2 particular software pacthes are required
                      for S/W version 11.
                   HRI (off position):
                    - low countrates at the beginning of the contact
                    - therefore UV calibration was switched on
                    - slowly increasing countrates, which could mean that
                        the HRI was not saturated at the beginning of the contact



  12:29:15   WHM3  AMCS:
                     Memory load in order to undo a previous memory load.

                     The status of the AMCS S/W version 11 should now be 'native'.
                   HRI:
                     BGR countrate between 10 and 30; image was worse during
                     the previous contacts.

  14:09:00   WHM4  AMCS: step 1 of recovery (see WHM 1).
                   HRI:
                     - Quiet at the beginning of the contact.
                     - HRI was moved into focus and immediately afterwards
                         out off position; countrate increased to more than
                         1000 cts/s (in focus) and returned to several
                         10 cts/s afterwards.

  15:48:30   WHM5  AMCS: again in safemode (!)
                   HRI: same experiment as in WHM4


    No further activities today.


Fri 1998-10-02 (DoY 275)

    AMCS is in 'safemode'.
    HRI is operated nominally, and in off position.

    Problems with the recovery yesterday were probably due to an
    erroneous determination of the intial sun pointing.

    Another recovery will be tried today; the final target will be Vega.


  09:03:00   WHM1  HRI: off focus; partly UV calibration
                    - low background rate before UV calibration (10-20 cts/s)
                    - UV calibration:
                       * roughly 700 cts/s
                       * several dark regions
                           (caused by parts of the UV filter lying directly
                            on the channel plates?)
                       * overall impression: improved status of HRI;
                           there is still some hope left (?)
                   AMCS: step 1 of recovery
                    - careful check of the pointing direction
                    - strange rotation towards the end of the contact

  10:41:00   WHM2  AMCS: again in safemode (same reason as yesterday ...)
                   HRI: not worse than before.


    No further activities during the weekend.


Mon 1998-10-05 (DoY 278)

    AMCS is in 'safemode'.
    HRI is operated nominally, and in off position.

    A recovery will be tried today; the final target will be Vega.

    Recoveries cancelled due to computer problems on ground.
    No further recovery today.


Tue 1998-10-06 (DoY 279)

    AMCS is in 'safemode'.
    HRI is operated nominally, and in off position.

    A recovery will be tried as soon as a more secure procedure has been
    developed and higher priority needs (EUTELSAT) have been satisfied.

    No recovery today.


Wed 1998-10-07 (DoY 280)

    AMCS is in 'safemode'.
    HRI is operated nominally, and in off position.

    During future recoveries magnetometer updates of the actual
    quaternion will not be allowed until the full
    attitude information derived on ground has been commanded.
    Furthermore the program used to determine the full attitude
    information should be more reliable now.

  08:19:30   WHM2  HRI:
                     - moved HRI to a position further off focus
                     - low background rates during the contact (at 10 cts/s)
                     - check whether pattern on HRI changes
                         if yes: due to external reasons
                         if no:  due to damage of the channel plates

  09:59:00   WHM3  AMCS recovery step 1: ok.

  11:39:00   WHM-  Weilheim antennas are not available during this pass.

  13:18:30   WHM4  AMCS recovery step 2: ok
                    - Earth block during the contact
                    - a few updates of the actual quaternion
                        (one by more 10 deg)

  14:58:30   WHM5  AMCS recovery step 3: at Vega (!)
                    - no identification of guide stars at the 
                        beginning of the contact
                    - acquisition after 'enable WFC Resets by AMCS'
                        had been sent.

    No more actions today.


Thu 1998-10-08 (DoY 281)

    AMCS is in 'degraded pointing mode', S/C points to Vega.
    HRI is operated nominally, and in off position.

  06:33:45   WHM1  AMCS: still in 'degraded pointing mode'
                    - several updates in RA and Dec during the contact
                    - never (?) steady during the contact
                   HRI:
                    - switched off, moved into focus, switched on for
                      a few seconds, switched off again, moved to off position,
                      switched on again
                    - low countrates at off position
                    - very high countrates in focus ( > 1000 cts/s )

  08:10:45   WHM2  HRI: same procedure as in WHM1; longer exposure on Vega
                    - no science (80x) frames although the HRI master reset
                        command was sent several times
                    - reasonable countrates at off position (< 10 cts/s)
                    - very high countrates in focus 
                        (<6000 cts/s, then 2500 cts/s HRSTVALEV)
                    - capacity of onboard tapes was exceeded
                    - tape dump was performed
                    - HRI was switched off at the end of the contact
                   AMCS: never steady (though it should)

  09:50:30   WHM3  HRI:
                    - off and in off position, moved into focus, 
                        HV switched on for several minutes,
                        switched off and moved to off position
                        at the end of the contact
                    - the HRI master reset command had to be sent;
                        afterwards, science frames (80x) were received 
                        for a few minutes
                    - countrate was at 6000 cts/s, later at 2500 cts/s
                    - much more valid (>1000) than invalid (roughly 100) events
                    - it is not clear whether Vega was really in the FOV 
                        of the HRI (see AMCS)
                   AMCS: never steady (though it should)
                    - next target will be WFC Meaty
                        (RA,Dec) = (247.266 deg, 78.074 deg)
                        slew scheduled for 11:10 UT.

  11:30:30   WHM4  AMCS: on WFC Meaty, and steady during most of the contact
                     (that means: we know, where we are)
                   HRI: same game as in WHM3
                     - countrates at 3500 cts/s, later at >7000 cts/s
                     - telemetry sync lost during part of the contact
                         (master reset commanded)
                     - off focus, and HV off at the end of the contact.

  13:10:00   WHM-  Weilheim antennas are not available during this pass.

  14:50:15   WHM5  AMCS: on WFC Meaty, and steady during most of the contact
                   HRI: play around with PHA LL and HV 
                     - HV ON and PHA LL = 3
                     - HV at 14, wait 30 s, to 13, ... to 10, wait 30s, to 0
                     - off focus at the end of the contact
                     - countrates: starting with 11000 cts/s, and
                         dropping to half of the value with each
                         decrease of the HV
                     - lost telemtry sync at HV = 11 (no science data)


Fri 1998-10-09 (DoY 282)

    AMCS is in 'degraded pointing mode', S/C points to WFC Meaty.
    HRI is switched off, and in off position.

  08:02:15   WHM2  HRI: play around with PHA LL
                    - moved into focus; switched on (HV step 14); PHA LL = 0
                        roughly 4000 cts/s
                    - increased PHA LL from 0 to 3;
                        countrate increased (!) to 11000 cts/s 
                    - HRI off at the end of the contact
                   AMCS: steady from time to time

    Switch on HRI during the next ROSAT night, when pointing to the
    dark Earth (i.e. the UV darkest region in the sky).

  09:42:15   WHM3  AMCS: safemode (!)

  11:22:00   WHM4  AMCS: recovery step 1 (successful)

  13:01:30   WHM5  AMCS: recovery step 2 (successful)
                          - commanding guide star catalogue
                          - enable magnetometer updates
                          - suspicion: sun sensor updates were disabled
                              as well before this contact
                              (large update of the sun angle)

  14:42:30   WHM6  AMCS: back to timeline, if everything looks ok.
                   HRI: HV off, and in off position.

    During the weekend the new AMCS software will be tested under
    nominal conditions (nominal timeline).


Mon 1998-10-12 (DoY 285)

    AMCS is in 'safemode'.
    HRI is switched off, and in off position.

    No further recovery until safemode data have been analyzed.


Wed 1998-10-14 (DoY 287)

    AMCS is in 'safemode'.
    HRI is switched off, and in off position.

    Observe the brightest X-ray source which is visible during the
    Weilheim contacts:
      RA = 115.828 deg, Dec = 28.885 deg (Sigma Gem; 8 cts/s in RASS/PSPC)

  09:00:30   WHM4  AMCS: recovery step 1 (successful)

  10:40:15   WHM5  AMCS: recovery step 2 (successful?)
                   HRI:
                     - was moved into focus and switched on
                         (target: bright Earth!)
                     - off focus, HV off at the end of the contact

  12:10:00         slew to Sigma Gem

  12:20:00   WHM6  AMCS:
                     - still slewing at the beginning of the contact
                     - steady periods at the end of the contact
                   HRI:
                     - moved into focus; HV was switched on
                     - countrates at 2500 cts/s
                     - source was not visible when satellite was steady
                     - HV off, moved to off position at the end of the contact


Thu 1998-10-15 (DoY 288)

    AMCS is in 'degraded pointing mode', S/C points to Sigma Gem'.
    HRI is switched off, and in off position.

    Plans for today:
      - HRI: move into focus and switch on for a full orbit 
          (between to WHM contacts); get Sigma Gem, 
          Dark and Bright Earth data.
      - AMCS: go back to nominal timeline after the WHM cycle;
          disable STCW stars shortly (? 30 s) before and shortly (? 90 s)
          after the slew start times (workaround for a bug in the
          AMCS software which 'disrupts' the timeline).


  08:52:15   WHM4  AMCS: steady during most of the contact
                   HRI:
                     - move into focus; switch on HV
                     - countrates at 5000 cts/s (HRSTVALEV),
                         or a few 100 cts/s (valid/invalid events)
                     - HRI remains in focus and switched on until 
                         the next contact

  10:31:45   WHM5  HRI:
                     - played around with PHA LL (0, then 1, then 3)
                     - sync lost atsome point; fixed by HRI master reset
                     - switched off and moved to off position at the
                         end of the contact.
                   AMCS:
                     - no star control at the beginning of the contact
                     - as soon as stars were identified, a continuous
                         increase of the wobble amplitude in x direction
                         was observed (starting at 3 arcmin, 
                         finally at 10 arcmin)

  12:11:45   WHM6  HRI: off; in out-of-focus position
                   AMCS:
                     - change (increase) scaling factor from CSS1 to CSS3;
                         should avoid halt at the rim of the sun cone as
                         observed during the safemode on 1998-10-10
                     - resend feedback parameter from STCW to AMCS
                         (in order to make sure that the correct value is used)
                         (should result in smaller wobble amplitudes;
                         currently at 10 arcmin)
                     - return to timeline; disable stars from STCW
                         shortly before and shortly after slew start times


Fri 1998-10-16 (DoY 289)

    AMCS is in 'degraded pointing mode', S/C is observing according to timeline.
    HRI is switched off, and in off position.

    Plans for today:
      - HRI:  play around with HV
      - AMCS: continue with timeline


  07:03:45   WHM3  HRI:
                     - move into focus; switch on HV
                     - reduce HV to step 12, then to step 10;
                         countrate decreases from 6000 cts/s to
                         several 100 cts/s
                     - HRI is operated in focus until the next WHM contact

  08:43:45   WHM4  HRI:
                     - increase HV to step 11
                         countrate increases from several 100 cts/s to
                         about 1500 100 cts/s
                     - HRI is operated at this HV until the next WHM contact

  10:23:15   WHM5  HRI:
                     - increase HV to step 12

  12:03:45   WHM6  HRI:
                     - HRI not in sync
                     - switched off HV; moved to off position

    Timeline had to be deleted up to the end of the next Weilheim cycle
    since 'security slews' had not been implemented; continuation of the
    timeline on 1998-10-17 at 12:18:40 UT.


Mon 1998-10-19 (DoY 292)

    AMCS is in 'safemode' (since Sunday morning).
    HRI is switched off, and in off position.

    No recovery until the reasons for the safemode have been analyzed.


Tue 1998-10-20 (DoY 293)

    AMCS is in 'safemode'.
    HRI is switched off, and in off position.

    Still no data from the last safemode (DTS problems), therefore no recovery.


Thu 1998-10-22 (DoY 295)

    AMCS is in 'safemode'.
    HRI is switched off, and in off position.

    Today we will try to acquire Cyg X-1, a bright, hard X-ray source:
      R.A. = 299.5913 deg
      Dec  =  35.1990 deg
      PSPC countrate 61 cts/s, ROSAT hardness ratio 0.98 (RASS)
      Visible over Weilheim, shortly after Earth block
      Within CVZ sometime next week
      Observing window:  1998-10-10, 21h  to  1998-12-02, 07h

  04:33:30   WHM3  AMCS: recovery step 1 (successful)

  06:13:30   WHM4  AMCS: recovery step 2 (successful)

  07:53:00   WHM5  AMCS: no action due to computer problems on ground

  09:33:00   WHM6  AMCS: recovery step 3 (start slew to Cyg X-1) (ok)

  14:16:53   WPS   AMCS: steady; amplitude increasing from <2 to >10 arcmin


Fri 1998-10-23 (DoY 296)

    AMCS is in 'degraded pointing mode'; S/C is pointing to Cyg X-1.
    HRI is switched off, and in off position.

    Today we will try to detect Cyg X-1 with the HRI.
    Due to instabilities of the AMCS Cyg X-1 will move by +-10 arcmin 
    around the detector center, which should allow to sample the
    sensitivity of various regions of the detector.

  06:05:00   WHM4  AMCS: 
                     - switching between steady and transient
                     - amplitude about 10 arcmin, period several 10 s

  07:44:30   WHM5  HRI:
                     - moved into focus; switched on to HV step 14, then 11
                     - PHA LL=0, UL=3
                     - about 10000 cts/s (slightly decreasing), 
                         1000 cts/s at step 11
                     - practically no photons in the central region of the HRI
                         along the line where Cyg X-1 is expected;
                         most photons are 'generated' at the rim of the HRI.
                         Now I am absolutely convinced that the HRI is 
                         definitely lost and can't be used for anything.

    Between WHM5 and WHM6 the HV is increased by one step every 10 minutes:
      HV at 10/11/12/13/14/11 at UT 07:52/08:02/08:12/08:36/08:46/08:56

  09:24:45   WHM6  HRI:
                     - switched off; moved to off position
                   AMCS:
                     - usual behaviour (swinging by +-10 arcmin or more)


Mon 1998-10-26 (DoY 299)

    AMCS is in 'degraded pointing mode'; S/C is pointing to Cyg X-1.
    HRI is switched off, and in off position.


  07:19:00   WHM5  AMCS: unchanged 
                     (steady and transient periods; amplitude 10 arcmin)

  13:42:47   WPS   AMCS: 
                     - steady and transient at the beginning of the contact
                     - continuously transient at the end of the contact


Tue 1998-10-27 (DoY 300)

    AMCS is in 'degraded pointing mode'; S/C is pointing to Cyg X-1.
    HRI is switched off, and in off position.


  07:10:45   WHM5  AMCS: 
                     - still on Cyg X-1
                     - steady and transient periods

  13:34:19   WPS   AMCS:
                     - is on timeline (not requested by anybody)
                     - Earth block during the contact

  20:04:45   ---   AMCS safemode triggered.


Wed 1998-10-28 (DoY 301)

    AMCS is in 'safemode'.
    HRI is switched off, and in off position.


Thu 1998-10-29 (DoY 302)

    AMCS is in 'safemode'.
    HRI is switched off, and in off position.

    The long delay times between star measurement and star identification
    cause large wobble amplitudes (10 arcmin).
    We now try to derive angular velocities again from the sun sensor,
    and disable the STCW angular velocities.
    The corresponding checks and commands will be done and sent this
    afternoon during the Wallops contact.

    Furthermore, star identification will be disabled during ROSAT nights;
    this should help to reduce the large nutation cones observed 
    during ROSAT nights, and to avoid further safemodes
    (on the cost of observing time).

    A recovery is scheduled for tomorrow morning.


  11:37:54   WPS   AMCS:
                     - check allowed time difference range for 
                         STCW angular velocities (should be ?2s-10s): ok
                     - command new time difference range (2s-3s),
                         thus disabling STCW angular velocities: ok


Fri 1998-10-30 (DoY 303)

    AMCS is in 'safemode'.
    HRI is switched off, and in off position.


  05:05:30   WHM5  AMCS: recovery step 1 (ok)

  06:45:30   WHM6  AMCS: recovery step 2 (ok)
                     - remain on arbitrary target (ok)
                         (R.A.,Dec) = (329 deg, -60 deg)
                         (advantage: sun angle == 90 deg)
                     - Earth block during contact

  11:29:19   WPS   AMCS: not in safemode

    For some reason the sunsensor update threshold was set to 10 deg, and
    not at 50 deg as intended. Several safemodes can be explained
    by this fact (those for which the satellite did not
    return to the allowed sun cone after a ROSAT night).
    The correct value has been commanded today.


Mon 1998-11-02 (DoY 306)

    AMCS is in 'degraded pointing mode'; 
      S/C is pointing to an arbitrary (recovery) target.
    HRI is switched off, and in off position.


  04:40:00   WHM5  AMCS: not in safemode

  11:03:30   WPS   AMCS: back in safemode

    According to GSOC the battery was in a bad state on Friday last week
    (although ROSAT was in safemode since Tuesday evening).
    Furthermore a workaround for disabling STCW information during night
    will not be available before tomorrow.
    Therefore no recovery will be performed during the next Weilheim cycle.


  23:50:00   TT    HRI: UV calibration sequence (off focus)

                     DoY::hh:mm:ss           HV  LL  UL
                     ----------------------------------
                     306::23:50:00           10   0   3
                             52              10   1   3
                             54              10   2   3
                             56              10   3   3
                             58              10   3   0

                     307::00:00:00           11   0   3
                             02              11   1   3
                             04              11   2   3
                             06              11   3   3
                             08              11   3   0

                          00:10:00           12   0   3
                             12              12   1   3
                             14              12   2   3
                             16              12   3   3
                             18              12   3   0

                           (belt)

                          00:30:00           13   0   3
                             32              13   1   3
                             34              13   2   3
                             36              13   3   3
                             38              13   3   0

                          00:40:02            0   3   0


Tue 1998-11-03 (DoY 307)

    AMCS is in 'safemode'.
    HRI is switched off, and in off position.



    The commands for the upper SS update threshold (50 deg) and the
    upper value for the allowed time difference between two star measurements
    (3 s) will be sent AFTER the next recovery, thus they will not be
    overwritten.
    The workaround for disabling the STCW during ROSAT night should be available
    by tomorrow.


Wed 1998-11-04 (DoY 308)

    AMCS is in 'safemode'.
    HRI is switched off, and in off position.

    The next recovery will not be performed before Friday evening
    (currently all WHM contacts occur during night, and DSN contacts
     are not available due to Space Shuttle flight).


Fri 1998-11-06 (DoY 310)

    AMCS is in 'safemode'.
    HRI is switched off, and in off position.

  21:58      CNB   AMCS: recovery step 1 (?)

  22:58:00   WHM3  AMCS: recovery step 2 (?)

    The sun pointing target will be continuously observed during the weekend.
    Checks to be done on Monday:

      1) Are there big nutation cones during the ROSAT night, although
            STCW control is disabled during night?
      2) If there are big nutation cone:
            Does the pointing direction return to the sun cone
            within the safemode delay time (600 s)?

    Assumptions: 

      1) STCW control is disabled during night
           (by commands automatically generated by ROSMAC).
      2) Angular velocities are derived from the sun (only during day),
           and not from the STCW information
           (by the 10 s to 3 s reduction of the corresponding upper threshold)
      3) The SS update threshold has been set to 50 deg.


Mon 1998-11-09 (DoY 313)

    AMCS is in 'degraded pointing mode';
      S/C is pointing to an arbitrary (recovery) target.
    HRI is switched off, and in off position.

    Analysis of the weekend data:

      - Stars were never identified; checks / possible reasons:
          * Resets are sent by the AMCS, and accepted by STCW.
          * Alternating STCW source flag (no STCW control during ROSAT night)
              was in princip commanded, though it is not yet clear, whether
              the tiny details were done correctly.
          * Another explanation would be that the nominal roll angle around 
              the sun direction does not correspond to the true angle
              (is off by more than ?10 deg, the upper threshold for 
               magnetometer updates).
      - Big sun cone offsets are built up during the ROSAT nights.
          The return into the sun cone after the ROSAT night seems to work
          fine now (good).

    As it turned out, nominal and actual pointing direction did not match
    by more than specified by the upper magnetometer update threshold
    (one reason for this could be that the magnetometer updates
    were not enabled at the end of the recovery;
    another reason could be that the roll angle around the sun axis
    again was not determined correctly during the recovery).


 ?14:00      AGO   AMCS:
                     - s/c put into safemode for a short period (reason: ROSMAC)
                     - step 1 of recovery

  19:14:15   WHM1  AMCS:
                     - step 2 of recovery

  20:52:45   WHM2  AMCS:
                     - slew to SN 1987A (RA=83.867deg, Dec=-69.270deg)
                         purpose: check whether targets in the LMC
                           can be acquired


Tue 1998-11-10 (DoY 314)

    AMCS is in 'degraded pointing mode'; S/C is pointing to SN 1987A.
    HRI is switched off, and in off position.

    The recovery target and SN 1987A were acquired without problems
    last night. The wobble amplitudes are at 3 arcmin (instead of
    10 arcmin when angular velocities were derived from the stars;
    the velocities are now derived from the sun sensors!).

    Today we will slew to Cyg X-1; we will check by a few offset pointings
    whether Cyg X-1 can be detected in the corners of the HRI,
    where the UV calibrations showed a similar behaviour as 
    before the damage.

    Preliminary Cyg X-1 observing program:

     Time    duration  HV  LL  UL  target        Cyg X-1 (hopefully) at
      UT        s                                detector coordinates
     ----------------------------------------------------------------
     21:45    1200     14   3   0  Cyg X-1 pos 1   905, 905
     22:05    1200     14   0   3  Cyg X-1 pos 1

     23:20    1200     14   0   3  Cyg X-1 pos 2  3190, 905
     23:40    1200     14   3   0  Cyg X-1 pos 2

     01:00    1200     14   3   0  Cyg X-1 pos 3   905,3190
     01:20    1200     14   0   3  Cyg X-1 pos 3

     Detector coordinates: as transmitted in telemetry
        (1 pixel is 0.557 arcsec; center at 2048,2048;
         origin is at the upper left corner in my colour images)

     After the Weilheim cycle we return to the nominal timeline.
     STCW control will be disabled during slews, but not during nights
     (there should be no longer be a problem with STCW control during
     night, since the s/c returns now reliably into the sun cone after
     the nights).


Wed 1998-11-11 (DoY 315)

    AMCS is in 'degraded pointing mode'; S/C should be on nominal timeline.
    HRI is switched off, and in off position.

    During the next Weilheim cycle we will try to fully recover the WFC,
    in order to check for the first time after the sun pointing on 1998-Sep-20
    whether there was a damage of the WFC.


Thu 1998-11-12 (DoY 316)

    AMCS is in 'degraded pointing mode'; S/C should be on nominal timeline.
    HRI is switched off, and in off position.
    WFC is operated nominally.


  07:58:36   WPS   AMCS: in safemode!

    Recovery not before tomorrow evening (no sun during WHM cycle today).

  17:12:45   WHM1  AMCS: 
                     - check contents of RAM word 0C06x
                         (nominator of CSS1/CSS3 scaling);
                       * should be 5332x, corresponding to a scaling value
                           of 1.298, if last recovery was done correctly
                       * analysis of DoY 313 data led to the conclusion
                           that the scaling factor was wrong after the last
                           recovery, leading to scaled small positive
                           values for CSS3 from large negative values from CSS1.
                       * value is ok (checked).


Fri 1998-11-13 (DoY 317)

    AMCS is in 'safemode'.
    HRI is switched off, and in off position.
    WFC is in safemode.

    Recovery will be tried using a DSN contact before WHM5.
    STCW control will be disabled during slew and night
      (during night STCW control obviously causes
       large nutation cones which in turn lead to safemodes).

  23:28:54   WPS?  AMCS: recovery step 1
  01:18:15   WHM6  AMCS: recovery step 2

    Recovery was ok (targets were acquired).


Sat 1998-11-14 (DoY 318)

    AMCS is in 'degraded pointing mode'; S/C is on nominal timeline.
    HRI is switched off, and in off position.
    WFC is in safemode.

  13:02:26   ---   AMCS: safemode triggered


Mon 1998-11-16 (DoY 320)

    AMCS is in safemode.
    HRI is switched off, and in off position.
    WFC is in safemode.

    A recovery will be tried during the next WHM cycle; final target
    will be (331 deg, -22 deg) (opposite to radiant of Leonides 
    meteor shower); no return to timeline before tomorrow night.


Tue 1998-11-17 (DoY 321)

    AMCS is in 'degraded pointing mode'; S/C is pointing to 'Anti-Leonides'
    HRI is switched off, and in off position.
    WFC is in safemode.

    Return to timeline after the next Weilheim cycle this evening.


Wed 1998-11-18 (DoY 322)

    AMCS is in 'degraded pointing mode'; S/C is on nominal timeline.
    HRI is switched off, and in off position.
    WFC is in safemode.

  14:01:23   ---   AMCS: safemode triggered
                     - target acquired before ROSAT night
                     - large nutation cone (30 deg radius) starting at 
                         the transition to the ROSAT night
                     - CSS3 nearly constant at -4 V after the ROSAT night
                         several attitude updates every 120 s, which are 
                         immediately corrected afterwards.


Thu 1998-11-19 (DoY 323)

    AMCS is in 'safemode'.
    HRI is switched off, and in off position.
    WFC is in safemode.

  16:07:45   WHM1  AMCS: recovery step 1

    Return to timeline at the end of this Weilheim cycle.


Fri 1998-11-20 (DoY 324)

    AMCS is in 'degraded pointing mode'; S/C is on nominal timeline.
    HRI is switched off, and in off position.
    WFC is in safemode.

    A procedure 'ram_test.ins' has been developed which dumps the contents
    of certain AMCS parameters. In future, this procedure will be commanded
    every day during WHM1, and after a Safemode or a recovery.
    Thus a regular log of important AMCS parameters will be available
    for a sound analysis of AMCS problems.


  14:23:15   WHM1  AMCS:
                     - not in safemode
                     - 'ram_test.ins' was sent for the first time


Mon 1998-11-23 (DoY 327)

    No safemode during the weekend.

    AMCS is in 'degraded pointing mode'; S/C is on nominal timeline.
    HRI is switched off, and in off position.
    WFC is in safemode.

    The WFC will be recovered during the next Weilheim cycle,
    and 'Meaty' will be observed according to request of WFC team.


Tue 1998-11-24 (DoY 328)

    AMCS is in 'degraded pointing mode'; S/C is on nominal timeline ('Meaty').
    HRI is switched off, and in off position.
    WFC is operated nominally.

    Next we will try one of the WFC final targets
      (ROR 180320, target 'RE1149', a CV, 
       at R.A. = 177.4814 deg, Dec. = 28.7524 deg; filter S1A).


Wed 1998-11-25 (DoY 329)

    AMCS is in 'degraded pointing mode'; S/C is pointed to 'RE1149'.
    HRI is switched off, and in off position.
    WFC is operated nominally.


Fri 1998-11-27 (DoY 331)

    AMCS is in 'degraded pointing mode'; S/C is pointed to 'RE1149'.
    HRI is switched off, and in off position.
    WFC is operated nominally.

    Next Sunday or Monday the CSS1/CSS3 scaling factor will be restored
    to its old value. The intention is to avoid cases where the
    pointing direction is trapped at the rim of the sun cone
    at the transition from CSS1 to CSS3 control.

    Probably on Monday we will return to the timeline.


Sat 1998-11-28 (DoY 332)

    AMCS is in 'degraded pointing mode'; S/C is pointed to 'RE1149'.
    HRI is switched off, and in off position.
    WFC is operated nominally.

  15:35:52   ----  AMCS: 
                     safemode triggered only 30 s after end of ROSAT night (!)


Mon 1998-11-30 (DoY 334)

    AMCS is in 'safemode'.
    HRI is switched off, and in off position.
    WFC is in safemode.

  14:32:00   WHM3  AMCS recovery step 1
                     - not completed since 'initial attitude not available'
                         (due to alignment of magnetic field and sun direction?)

  16:12:00   WHM4  AMCS recovery step 1 (retry)
                     - seems to be ok


Tue 1998-12-01 (DoY 335)

    AMCS is in 'degraded pointing mode'; S/C is on nominal timeline.
    HRI is switched off, and in off position.
    WFC is in safemode.


Wed 1998-12-02 (DoY 336)

    AMCS is in 'degraded pointing mode'; S/C is on nominal timeline.
    HRI is switched off, and in off position.
    WFC is in safemode.

  10:14:42   ----  AMCS: safemode triggered
                     roughly 60 s after end of ROSAT night;
                     (due to missing presence in CSS3)

  12:35:15   WHM2  AMCS recovery step 1 (ok)

  14:15:15   WHM3  AMCS recovery step 2
                     problems at GSOC (according to ATOR)

  15:55:00   WHM4  AMCS recovery step 2 repeated

  17:34:30   WHM5  AMCS recovery complete; 'steady' during the contact


Thu 1998-12-03 (DoY 337)

    AMCS is in 'degraded pointing mode'; S/C is on nominal timeline.
    HRI is switched off, and in off position.
    WFC is in safemode.




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