25 Mar 2010 10:57

The "Herschel Observatory Routine Science Phase Readiness Review", conducted this month and fed by the SPIRE and PACS instrument and Instrument Control Centre (ICC) reviews, concluded that the observatory is ready for Routine Science Phase operations with these two instruments.

Spacecraft

The spacecraft is operating nominally.

Star tracker warm pixels
Following a series of further tests to mitigate the star tracker "warm pixel" anomaly, the star tracker CCD temperature will be permanently lowered to -10 °C from 29 March 2010 onward. No measurable hysteresis from CCD temperature cycling could be detected and the change in the instrument versus star tracker boresight, derived from more than 100 PACS pointings, is a reproducible 2 arcseconds which has been corrected for in a new alignment matrix.

To more fully characterise the star tracker behaviour at the new CCD temperature settings, for the time being full CCD dumps continue to be produced every two weeks. These are used to determine what effect, if any, the new temperature regime has on the clustering and dynamics of "warm" pixels. In parallel, procedures are being prepared to regularly update the star tracker "bad pixel table" based on the findings of the bi-weekly CCD dumps.

Payload

Both PACS and SPIRE continue to operate nominally.

The Performance Verification Phase for the HIFI instrument was successfully concluded. As of 21 March, HIFI has also completed 60% of its Science Demonstration Phase and 40% of its Priority Science Programme (about 450 hours of observations extracted from the Key Programmes that have been assigned highest scientific priority).

Ground Segment

Mission Operations
During the reporting period, mission operations have been conducted with the support of the ESA New Norcia ground station. Observational data stored on-board Herschel was received on ground during communication passes lasting approximately three hours.

Archiving
The ground segment is operating nominally. Data products are generated routinely and ingested into the Herschel Science Archive (HSA) within 24 hours of an observation being made.

Using improved pipeline generation software, all data obtained from standard observations so far are currently undergoing bulk reprocessing to update the HSA with the best available science products that can be generated in an automated way at this time.

The HSA, populated with a number of Science Demonstration Phase observations, has been opened to the public. For a short period there was a noticeable increase in the number of external users of the archive and in the number of scientific products that were downloaded.

Future Milestones

• 14 May 2010: First anniversary of launch
• May 2010: Issuing of first in-flight Announcement of Opportunity (AO) for Open Time (OT1) observations

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Legal disclaimer
This report is based on the Herschel mission manager's report dated 21 March 2010. Please see the copyright section of the legal disclaimer (linked from the home page http://sci.esa.int) for terms of use.