Editor's note: A very quick update before we head off to Toulouse to cover ATV docking - all's well that end's well with Rosetta's longer-than-expected manouevre campaign. SOM Andrea Accomazzo confirmed this morning that the final manourvre was indeed completed on 17 February
I met on 10 February with Rosetta Spacecraft Operations Manager Andrea Accomazzo here at ESOC to catch up on all that's happened with Rosetta since our last update on 18 January.
Click to listen (or download) a full, 8:00-min recording of his explanation below, but to summarize, here is what has been happening:
- Rosetta experienced a safe mode - an automatic reset of the spacecraft - that happened during the thruster burn late in the evening of 18 January
- The safe mode stopped the thruster burn and placed the spacecraft into a basic, safe, Earth-pointing mode, waiting commands
- The teams here at ESOC spent the next few days determining the cause - which seemed to relate to how the thrusters function when in continuous operation
- In part by using a number of advanced tools and techniques developed here by the Advanced Mission Concepts and Technologies Office, the Rosetta team were able to isolate the problem
- The flight control team worked with flight dynamics experts to devise a new mode of operation for the thrusters - basically commanding them to switch rapidly on and off instead of running continuously as before
- The new thruster mode was extensively tested and simulated using software and the Rosetta engineering model, which is kept here at ESOC for just such purposes.
- A new set of manoeuvres were planned and uploaded, and during the last week of January, the spacecraft successfully re-started the manoeuvre campaign
- It has now completed almost 98% of the required change in velocity and is more or less lined up to meet Comet 67P/Churyumov-Gerasimenko in 2014
- The final manoeuvre of this new campaign will be conducted today, starting at 19:38 CET and running for about 43 minutes
Andrea and the rest of the team here at ESOC are just delighted! An initial problem that caused real concern and could have become critical has been investigated, analysed and a fix found - which enables the spacecraft to perform even better than before.
We'll update you again when we have news on the start of Rosetta's long hibernation, scheduled now for the June 2011 timeframe. -- Daniel
If audio does not play, download the original mp3 file here.