for two weeks, starting on 29 july, the amateur skywatchers were unable to find the spacecraft in the locations they had predicted, leading them to believe it had suddenly changed its course. during the mission, the vehicle was observed to change its orbit multiple times, with a total delta-v of the first four orbit changes amounting to . a common characteristic of all the orbits was that the ground track nearly repeated every few days. by 12 november 2010, the orbit had been lowered to with the ground track now repeating every three days (47 orbits).