Just after I got back from Skye we heard the sad, but inevitable, news – Herschel had reached the end of its supply of liquid helium, and with that the end of science operations. The ESA press release can be found here, and BBC news coverage is here.
Herschel had a design life of 3 years for science operations, and we managed almost 6 months of extra life beyond that. In the last weeks Herschel’s unexpected longevity was becoming a bit of a problem as the observatory was running out of observations to perform. When the remorseful day came, those of us in the instrument teams were beavering away setting up observations for a new tranche of guaranteed time that had been allocated to us, but sadly that was not to be.
Things don’t finish here of course. There is a vast range of data collected by Herschel that will be studied in detail for many years. A mission archive, containing all the data Herschel collected, uniformly processed and calibrated with the final pipelines needs to be constructed. Even the spacecraft itself will carry on for a month or so more, conducting various technical tests, before finally being pushed away from L2 into an Earth-trailing graveyard orbit for a long and well deserved rest.
Meanwhile, we carry on working with the amazing data we’ve got from Herschel, and carry on planning the next and even greater space far-IR observatory.