Posted on 05/06/2014 by Daniel
Big Burn 2 complete
Last night’s orbit correction manoeuvre ran as expected, with nominal completion at 23:00 CEST (21:00 UTC).
The thruster burn got underway as scheduled at 16:21:58 CEST (14:21:58 UTC) and ran for 6hrs:39mins, about 2 minutes less than planned but well within margins. About 190 kg of fuel was used.
The manoeuvre was triggered automatically by a command stack that had been uploaded on Tuesday. Engineers were able to monitor the event in real time via ESA’s 35m deep-space antenna at New Norcia, Australia.
The Rosetta flight control team can’t say what the precise results were in terms of actual delta-v delivered until Flight Dynamics here at ESOC do a review and orbit determination, which takes a day or so, but if a burn runs for anywhere close to the planned time, then we know it went more or less OK – as it did (see note below).
Next OCM is planned for 18 June; details to follow.
Note: In fact, this variability in the actual thrust delivered versus what’s planned is one of the reasons why the required orbit corrections are being done in a series of smaller burns. Any variation in one burn can be made up in the next, helping the entire process to be more efficient and optimise the use of fuel.