While the overarching mission/concept has disturbing aspects, in all honestly it probably wasn't doing much of anything during its maiden voyage.
The biggest events were the changes in orbit, and that was probably mission control testing positioning thrusters and associated systems to prove the craft is capable of dropping in and out of a geostationary orbit and repositioning itself into different orbit patterns with ease + accuracy (and probably with little human involvement).
Given the craft hasn't passed a test of re-entry nor an automated landing from space, it seems unlikely the US Air force would have loaded sensitive + expensive monitoring equipment onboard, nuclear weapons or any of the other conspiracies - on this initial trip anyway.
The Air Force doesn't suffer from the same kind of planning paralysis as NASA, so I'm assuming they actually carried out some kind of mission. It's not clear to me what this thing is really good for, though. The payload bay is about the same size and shape as a coffin - far too small for the kind of sensors you find on spy satellites.
They might have some scheme cooked up for refueling spy sats, which would extend the service life and give them the ability to shift orbits more freely. Still... even then, would it really be cheaper than lofting a new one?
In theory they could fit a guy in there, barely. That might make some sense for repairs. Assuming you could find a good mechanic without a trace of claustrophobia. And assuming the flight profile didn't flatten him. Maybe some kind of teleoperated repair bot?
I'm not sure whether this could carry someone. The spacecraft doesn't have to carry just the body, but also oxygen, heating systems, waste disposal, food, …
Maybe you could fit someone inside, but that might just be the hardest mission ever flown.
You could fold quite a large collapsing antenna into that sort of space, and reconfigurable orbits would make very high resolution SAR scans available virtually on demand. I can see that being extremely useful.
SAR is indeed a great use for this kind of platform, but the equipment needed to do really high-quality work might be too bulky for this platform. The Shuttle Radar Topography Mission equipment (http://www2.jpl.nasa.gov/srtm/images/photos/srtm_22_lo.jpg) certainly wouldn't have fitted, given the description of the available space.
A friend of a friend who works for the government apparently was recently doing some work on high-speed interactions between orbiting bodies. Orbiting bodies like satellites and space planes? Time will tell...
Since it's maiden voyage I would guess not much other than a prolonged check-out, maybe some surveillance and/or mapping.
As for the overall mission mandate may directly or indirectly be related to prompt global strike, a kinetic kill system (either for satellites or for ground targets), or electronic warfare.
Neither of those strike applications make much sense for this platform. If you were going to put bombs in space you're only wasting payload capacity by including a ship.
The biggest events were the changes in orbit, and that was probably mission control testing positioning thrusters and associated systems to prove the craft is capable of dropping in and out of a geostationary orbit and repositioning itself into different orbit patterns with ease + accuracy (and probably with little human involvement).
Given the craft hasn't passed a test of re-entry nor an automated landing from space, it seems unlikely the US Air force would have loaded sensitive + expensive monitoring equipment onboard, nuclear weapons or any of the other conspiracies - on this initial trip anyway.