The table below contains all past CDMU Clock Events (either resets or wrap-around) as well as the next predicted wrap-around.
The current wrap-around period is: 16777365.93 secs (194 days, 04 hours, 22 minutes and 45 seconds), based on a drift factor (secs/count) of: 1.00000893650
The drift factor is not constant and has to be periodically re-evaluated; therefore, the prediction is within a few seconds of the real event (the table will be updated with the correct value after the event, and a new prediction will be made).
A CDMU reset brings the clock counts down to 0. In case of such an event, it will be reported in the table and a new wrap-around prediction will be determined. The reported times for CDMU resets indicate the time when the clocks resumed (although the CDMU problem had occurred earlier).
After a CDMU reset or a wrap-around the Instruments' clocks and the CDMU have to re-synchronized. This is either a manual Procedure or it automatically occurs at Instrument switch-on. The table indicates when the clocks re-sync took place for each event (and the potential impact associated with the delay between on-board clock re-start and Instruments' clocks re-sync).
Please view this
PDF File for details on the 2000's resets.
|
Instruments' Clock Events
|
| No |
Date & Time |
Rev |
Type |
Impact |
| 1 |
1999-12-10T08:54:55Z |
0000 |
Reset (Launch) |
None (nominal reset at Launch) |
| 2 |
2000-03-16T07:38:20Z |
0049 |
Reset |
CDMU anomaly occurred on Obs 0094810301. No more obs in rev 49 was performed. No clocks re-sync (but see next entry). |
| 3 |
2000-03-17T15:13:35Z |
0050 |
Reset |
CDMU anomaly. No obs for rev 50 was performed. Clocks re-sync via manual procedure before start of rev 51 (no impact). |
| 4 |
2000-06-17T16:07:37Z |
0096 |
Reset |
CDMU anomaly occurred on Obs 0006810101 (rev 96). Obs 0126700801 partially affected. Clocks re-sync effective before resumption of this obs. |
| 5 |
2000-06-30T13:59:22Z |
0102 |
Reset |
CDMU anomaly occurred on Obs 0099020301 (rev 102). Clocks re-sync for OM, EPIC-MOS1 and EPIC-MOS2 performed before re-sumption of science operations in rev 0103.
Clocks re-sync for RGS1, RGS2 and EPIC-PN had problems and was not effective until end of rev 0104. The following observations have, therefore, timing problems for RGS1/2 and EPIC-PN:
0103 0109970101
0103 0111020101
0103 0111020201
0104 0111130201
0104 0112650501
0104 0127110201
0104 0127120101
0104 0127160101
|
| 6 |
2001-01-10T18:21:20Z |
0200 |
Wrap-around |
Idle period.
Clocks re-sync via manual procedure (no impact). |
| 7 |
2001-07-23T22:43:26Z |
0298 |
Wrap-around |
No operations (ARTEMIS support).
Clocks re-sync at Instrument switch-on on rev 299 (no impact). |
| 8 |
2002-02-03T03:05:40Z |
0394 |
Wrap-around |
Idle period.
Clocks re-sync via manual procedure (no impact). |
| 9 |
2002-08-16T07:27:59Z |
0492 |
Wrap-around |
Idle period.
Clocks re-sync via manual procedure (no impact). |
| 10 |
2003-02-26T11:50:21Z |
0589 |
Wrap-around |
Idle period.
Clocks re-sync via manual procedure (no impact). |
| 11 |
2003-09-08T16:12:49Z |
0686 |
Wrap-around |
Idle period.
Clocks re-sync via manual procedure (no impact). |
| 12 |
2004-03-20T20:35:20Z |
0784 |
Wrap-around |
Idle period.
Clocks re-sync via manual procedure (no impact). |
| 13 |
2004-10-01T00:58:00Z |
0881 |
Wrap-around |
Idle period.
Clocks re-sync via manual procedure (no impact). |
| 14 |
2005-04-13T05:20:32Z |
0978 |
Wrap-around |
Idle period.
Clocks re-sync via manual procedure (no impact). |
| 15 |
2005-10-24T09:43:12Z |
1076 |
Wrap-around |
Idle period.
Clocks re-sync via manual procedure (no impact). |
| 16 |
2006-05-06T14:06:11Z |
1173 |
Wrap-around |
Idle period.
Clocks re-sync via manual procedure (no impact). |
| 17 |
2006-11-16T18:28:47Z |
1271 |
Wrap-around |
Idle period.
Clocks re-sync via manual procedure (no impact). |
| 18 |
2007-05-29T22:51:39Z |
1368 |
Wrap-around |
Idle period.
Clocks re-sync via manual procedure (no impact). |
| 19 |
2007-12-10T03:14:32Z |
1465 |
Wrap-around |
Clocks re-sync via manual procedure.
One EPIC slew observation skipped. |
| 20 |
2008-06-21T07:37:28Z |
1563 |
Wrap-around |
Clocks re-sync via manual procedure.
Observation start delayed untill end of re-sync. |
| 21 |
2009-01-01T12:00:25Z |
1660 |
Wrap-around |
Clocks re-sync via manual procedure.
Observation start delayed untill end of re-sync. |
| 22 |
2009-07-14T16:23:28Z |
1757 |
Wrap-around |
Idle period.
Clocks re-sync via manual procedure (no impact). |
| 23 |
2010-01-24T20:46:32Z |
1855 |
Wrap-around |
Idle period.
Clocks re-sync via manual procedure (no impact). |
| 24 |
2010-08-07T01:09:09Z |
1952 |
Wrap-around |
Idle period.
Clocks re-sync via manual procedure (no impact). |
| 25 |
2011-02-17T05:32:47Z |
2049 |
Wrap-around |
Idle period.
Clocks re-sync via manual procedure (no impact). |
| 26 |
2011-08-30T09:55:59Z |
2147 |
Wrap-around |
Obs 0674670101 affected. |
| 27 |
2012-03-11T14:18:41Z |
2244 |
Wrap-around |
Idle period.
Clocks re-sync via manual procedure (no impact). |
| 28 |
2012-09-21T18:42:28Z |
2342 |
Wrap-around |
Idle period.
Clocks re-sync via manual procedure (no impact). |
| 29 |
2013-04-03T23:05:44Z |
2439 |
Wrap-around |
Clocks re-sync via manual procedure.
One slew exposure skipped. |
| 30 |
2013-10-15T03:28:30Z |
2536 |
Predicted wrap-around |
No science to be scheduled around this time.
Clocks re-sync to be done via manual procedure. |
