ROSAT STATUS REPORT #4:

May 15th 1991

Current Status on the following is available:

SATELLITE:

On April 26th, difficulties were encountered with the uplinking of software patches to address problems of maintaining known attitude, this resulted in the satellite switching to safe mode (see updated blacklist for details of bad times). By April 30th, however, the problems were resolved. Operations proceeded smoothly until May 13th.

ROSAT's Y-axis gyro failed on Mon May 13th, sending the satellite into safe mode. The the Z and S (cross coupled) gyros are still functioning normally, but the X gyro is problematic (it had been removed from the control loop during the survey, after its drift rate exceeded specifications). An attitude reacquisition is planned for tonight. There appears to be no hope to retrieve the Y gyro.

A meeting is planned for today at the German Space Operations Center (GSOC) to assess the best strategy for continuation of the pointed program. It is expected that pointed observations will begin again within the next few days, once the appropriate modifications to the onboard software have been made. In the meantime, the satellite remains in the safe mode.

SASS (Scientific Analysis Software System) UPDATE:

SASS 5.0.1 has been installed at GSFC, and processing tests with this new version were performed using seven days of PSPC PCV data. Only half of these PCV data passed the "quality flag screening" portion of SASS. An additional test with two days of AO-1 PSPC data also failed due to what appeared to be the PSPC High Voltage flag exceeding the set limit. These problems are due to incorrect limits present in the quality parameter files that were obtained from MPE. MPE is aware of these problems and new limits will be incorporated in the new update of SASS.

After an intensive effort by members of the SAO team, in collaboration with MPE, the HRI data analysis software finally runs within SASS. MPE is currently preparing a "bug-fix" release of the SASS software that will also include revised interfaces (between SASS and the HRI software) and therefore permit HRI data to be processed successfully.

If the new update of SASS resolves these PSPC problems and the installation goes smoothly with no new major problems, the USRSDC plans to begin processing the first week in June, after first running an abbreviated end-to-end test.

PROS:

A "PROS advisory panel", with members representing several different institutions, has been formed to evaluate the current PROS data analysis system and make suggestions for improvements and future development. These suggestions will be discussed and prioritized when the panel meets during the Seattle AAS meeting. Current PROS users who wish to provide input to the panel should send electronic mail (before May 22) to:

rsdc@cfa.harvard.edu

The panel members (Frank Primini, SAO, chairman; J.-P. Caillault, U. of Georgia, beta-test site; Bill Forman, SAO, ROSAT Users Committee; John Nousek, Penn. State, ROSAT Users Committee; Bill Pence, GSFC, beta-test site; and Meg Urry, StScI, beta-test site) have agreed to serve through July, at which time the panel will issue its final report and disband.

SAO now provides a "hotseat" service for those needing help or encountering problems with running the PROS software; send email queries to:

hotseat@cfa.harvard.edu

MISSION TIMELINE:

The updated "black list" of lost-data times for the ROSAT timeline is given below and can be cross-checked with the detailed timeline (available through the MIPS system; lists start-times and durations for all scheduled targets) to determine whether a particular scheduled observation was lost:

 Start    UT       End     UT   Reason                                   
 7.2.91  7:11 -  9.2.91  5:12 SAFE MODE
 9.2.91 23:07 - 10.2.91 20:58 WFC filter position mismatch
22.2.91  5:50 - 22.2.91  6:41 no guide stars                           
22.2.91  9:08 - 22.2.91  9:13 no guide stars                           
22.2.91 16:28 - 22.2.91 17:16 no guide stars                           
22.2.91 18:57 - 22.2.91 19:00 no guide stars                           
22.2.91 19:54 - 22.2.91 20:06 no guide stars                           
23.2.91  3:19 - 23.2.91 23:46 AMCS STANDBY: NO POINTINGS               
25.2.91  1:23 - 25.2.91  2:02 guide star problems
27.2.91  9:02 - 27.2.91 13:35 WFC filter position mismatch
28.2.91 17:07 - 28.2.91 17:20 no reference stars
 2.3.91  5:15 -  2.3.91 13:34 WFC data lost / tape allocation
 2.3.91 10:17 -  2.3.91 16:54 FI  data lost / tape allocation
 3.3.91 23:45 -  5.3.91 18:51 AMCS STANDBY: NO POINTINGS               
 7.3.91  3:05 -  7.3.91  3:48 inconsistent attitude solution
 7.3.91 16:00 -  7.3.91 16:36 inconsistent attitude solution
 8.3.91 14:25 -  8.3.91 14:55 inconsistent attitude solution
11.3.91 19:20 - 11.3.91 19:40 inconsistent attitude solution
13.3.91 02:56 - 13.3.91 ca4h  no reference stars
15.3.91 11:40 - 15.3.91 12:40 inconsistent attitude solution
15.3.91 13:30 - 15.3.91 14:20 inconsistent attitude solution
17.3.91 17:58 - 17.3.91 23:15 spurious WFC AMCS safing triggered, no WFC data
19.3.91 15:14 - 19.3.91 16:01 spurious WFC AMCS safing triggered, no WFC data
19.3.91 19:55 - 19.3.91 20:21 bad telemetry data
24.3.91 18:15 - 24.3.91 18:45 bad telemetry data
25.3.91 07:04 - 25.3.91 10:22 special attitude maneuvers (gyro cal)
25.3.91 10:22 - 28.3.91  5:40 ca.75% lost due to solar activity (PSPC off)
28.3.91 10:35 - 28.3.91 18:20 SEU in WFC computer, no WFC data
30.3.91  8:34 - 30.3.91 10:15 spurious WFC AMCS safing triggered, no WFC data
 4.4.91  3:05 -  4.4.91  6:55 WFC CDHS crash (SEU?), no WFC data
 6.4.91 08:26 -  6.4.91 08:58 P27: reference stars: NONE, ONE or TWO
 6.4.91 09:07 -  6.4.91 18:19 reference stars: NONE (mostly)
 6.4.91 18:19 - 10.4.91  0:09 STANDBY, SAFE MODE, RECOVERY, FI turn-on
 8.4.91 19:42 -  8.4.91 ca22h no reference stars
14.4.91 18:40 - 14.4.91 ca21h no reference stars
21.4.91 17:00 - 22.4.91  1:49 guide star problems
22.4.91  1:49 - 23.4.91  0:55 STANDBY mode due to loss of attitude
23.4.91 18:51 - 23.4.91 20:28 WFC command conflict; no WFC data
23.4.91 22:25 - 24.4.91  2:30 Special gyro calibration slews
24.4.91 12:10 - 24.4.91 12:55 no guide stars
25.4.91 17:10 - 25.4.91 18:48 WFC command conflict; no WFC data
27.4.91  9:41 - 30.4.91  9:38 STANDBY, new AMCD software, SAFE MODE, FI turn-on
 2.5.91 15:40 -  2.5.91 19:06 FI coldstart and switch-on of Gas System; no FI

AO2:

Pre-review processing has been completed for the AO2 proposals. All proposals have been logged into the proposal database, and database reports have been mailed to all proposers. Proposals were mailed to the peer review team members last week, in anticipation of the peer review at the end of the month.

The U.S. response to AO2 can be summarized as follows:

Total proposals received:               406
Total time requested:                   21,507 ks (~7,000 accepted, ~4,000 
                                                        to be scheduled)
Total funding requested:                $11.7 million  (~$2.5 million available)
Total constrained time requested:       1,900 ks  (~200 ks available)

By class the proposals break down as follows:

+------+-------------+-----------+
| class| # proposals | time (ks) |
+------+-------------+-----------+
|     1|           68|   3928.424|
|     2|           12|    376.533|
|     3|           31|   1363.740|
|     4|           45|   1888.500|
|     5|           19|    801.100|
|     6|           46|   3153.900|
|     7|           79|   5240.341|
|     8|           52|   2880.300|
|     9|           16|   1260.100|
|    10|           16|    614.200|
+------+-------------+-----------+

{Classes are 1=normal stars, 2=white dwarfs, 3=CV's, 4=neutron stars,black holes, 5=SNR's, 6=normal galaxies, 7=AGN, 8=clusters of galaxies, 9=diffuse X-ray emission, 10=other}.

A total of 18 proposals were received from non_US PI's: 8from Italy, 4 each from India and Canada, and 1 each from the Netherlands and France.

A total of 23 "zero time" proposals were received: 12 for participation in non-US pointed observations, 11 for participation in analysis of survey data.

NOTE: The next status report will be issued later than usual, due to the ROSAT peer review.

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