Rosetta's Orbit

I am wondering how long it takes Rosette to make one orbit about the comet. The approach was done with numerous course corrections, but once you've actually matched velocities and are happy with your distance, I think that a nice stable orbit would be a really good idea, mostly because you wouldn't be using any of your limited supply of fuel just to maintain your position. But the comet has very little gravity, the escape velocity is less than one MPH. You could probably leave the comet if you jumped hard. Right now they are somewhere around 20 to 30 kilometers from the comet. If we assume one half mile per hour as the speed you need to maintain your orbit, and you run the numbers:



It's going to take Rosetta ten days to make a single orbit.And this is while the comet (and Rosetta) are hurtling around the sun at several miles per second.