Herschel Status Report - July/August 2012
Spacecraft
The spacecraft continues to be in good health and is operating nominally.
Payload
Operations for all three instruments, PACS, SPIRE and HIFI, have been nominal during the reporting period. Occasional HIFI and SPIRE single event upsets (SEUs) were routinely handled via standard procedures and in most cases had no impact on the science observations.
Ground Segment
Ground segment operations have been nominal and 100% of the data continues to be recovered. As of 24 August 2012, the approximate completion of the different programme parts was:
| KPGT | Key Programme Guaranteed Time | : | >99% |
| KPOT | Key Programme Open Time | : | >99% |
| GT1 | First in-flight Guaranteed Time | : | 98% |
| OT1 | First in-flight Open Time, high priority | : | 91% |
| First in-flight Open Time, lower priority | : | 3.8% | |
| GT2 | Second in-flight Guaranteed Time | : | 74% |
| OT2 | Second in-flight Open Time, priority 1 | : | 54% |
| Second in-flight Open Time, priority 2 | : | 0% |
For more details of the different programme parts, see the "overview of Herschel observing" linked from the right-hand menu.
Mission Operations
Throughout the reporting period, mission operations have been conducted with the support of ESA's New Norcia ground station. Observational data stored on-board Herschel was received on ground during daily communication passes, each lasting approximately three hours.
A temporary hardware problem at the ground station resulted in no command uplink being possible during the pass on 29 July. Herschel's on-board autonomy can cope with such a problem, and the commanding situation was fully recovered the next day.
On a number of days in early August the ground station's antenna azimuth rate exceeded the maximum capability in order to keep pointing at Herschel as the spacecraft's position on the sky passed directly overhead. This had no impact on operations as the minor gaps in the data downlink were successfully recovered on subsequent days.
A routine station-keeping manoeuvre, or orbit correction manoeuvre, was successfully performed on 17 August. These routine manoeuvres ensure the Herschel spacecraft maintains its correct orbit about L2.
Archiving
The ground segment is operating nominally. Data products are generated routinely and ingested into the Herschel Science Archive (HSA).
The fourth bulk reprocessing of all archived Herschel data, which began at the end of April, reached completion for all three science instruments by the end of July. Subsequent extended processing (combining selected datasets from related/adjacent observations with different instruments into combined products) was completed by 24 August.
Future Milestones
- 9-11 October 2012: HIPE Forum - Gathering of Herschel distributed developer community responsible for upkeep of the ground system and data processing software
- 30 October 2012: Post-Operations Readiness Review kick-off meeting
- February/March 2013: Predicted end of operational lifetime for scientific observations (exhaustion of the liquid helium for the spacecraft's active cooling system)
- 1 July 2013: Start of Post-Operations Phase
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Legal disclaimer
This report is based on the Herschel Mission Manager's report dated 29 August 2012. Please see the copyright section of the legal disclaimer (linked from the home page http://sci.esa.int) for terms of use.