As activity for the Rosetta Flight Control Team steadily winds down toward Friday’s end of mission, we’ve been hearing a number of ‘insider tales’ from the engineers, who are already reminiscing about their favourite moments from Rosetta’s epic journey. This was sent in by Armelle Hubault, spacecraft operations engineer responsible for automation, telecommanding and some of the instruments on Rosetta.
This is not a ‘funny’ story as such, but it is one of the most satisfying moments from my time on the Rosetta team, and it happened around the time of Lutetia flyby.
I am very bad at visualising things in 3D; that is, in visualising Rosetta’s attitude in space, at the correct position in the Solar System and with other objects around. This was especially so during the long cruise phase, when we were all over the place!
So while I was preparing for Lutetia flyby in summer 2010 , I was using a software package called Celestia to try and picture a bit what was happening. Doing so, I realised the software – which is pretty accurate – was showing me that, as we were approaching the asteroid, Saturn was just in the background. In fact, the software suggested a conjunction situation, in which the asteroid would lie between the spacecraft and Saturn! In other words, it was showing that the view from Rosetta to the asteroid would have Saturn in the background!
Now I know that this kind of simulation should be verified with care, so I contacted a colleague, Michael Küppers, at the Rosetta science operations centre, at ESAC near Madrid, who was dealing with spacecraft pointings and who knew a fair bit about our scientific camera.
I asked him if he could confirm what I was seeing – and whether it would be possible to take a picture? Saturn was very far and dim, Lutetia was very close and bright, and my Celestia software was not capable of determining whether Rosetta’s camera could successfully get such a photo.
After looking at it, Michael confirmed that it was indeed feasible, and the imaging request was added to the spacecraft commands to be sent up near the time of flyby.
The resulting image (see below) is one of which I am very proud, and I could not believe that no one else had noticed this conjunction!
Editor’s note: Read more about Armelle via https://spacewomen.org/space-women/armelle-hubault/