They don't even have to do that. As I understand it, they freely have the option to keep the money paid for them so far and just inform NASA that they are not f

They don't even have to do that. As I understand it, they freely have the option to keep the money paid for them so far and just inform NASA that they are not flying the 6 operational missions, and shut it down. The reason not to do that is that as stated above, most of the money in the contract is in those operational missions. Even if the contract will lose them money in total, if they think it will cost less to complete starting from right now than what those 6 pay out, it will make economical sense to keep trying.