My guess was to refuel spy satellites. I imagine those sats are tough and can survive a long time. But when they get low on gas they can only do station keeping. If you can count of fuel coming, there's a lot more freedom to shift the track a half a degree as needed.
It may be all electronic surveillance. I guess, you can count on satellites not changing after they're launched, so the electronics package would be good for a couple years. come back, get a new package for new surveillance.
Just delivering fuel though, has a lot of value, and you could keep using the same platform for a long long time. Seems to fit better with many multi year missions.
It may be all electronic surveillance. I guess, you can count on satellites not changing after they're launched, so the electronics package would be good for a couple years. come back, get a new package for new surveillance.
Just delivering fuel though, has a lot of value, and you could keep using the same platform for a long long time. Seems to fit better with many multi year missions.
I'm sure somebody knows. But, you know, not me.