Strategypage writes that the craft is proving to be very elusive:
A year ago, after seven months in orbit, the first X-37B flight (of 224 days) ended. Three months later, the second X-37B was launched. The X-37B also demonstrated that it could not be easily tracked while in orbit.
Ever mysterious, the X-37B proved elusive to amateur astronomers. Little is publicly known about what either X-37B was doing up there. The best guess is that it testing the endurance of new satellite components. That does not give amateur astronomers much to look at.
Some dismissed the craft as too small to be useful. I didn't understand that take, given that the "X" stands for "experimental," and that it could be scaled up if successfully tested. It will be:
The air force has revealed that it is designing an X-37C, which would be twice the size of the X-37B and able to carry up to six passengers. Think of it as Space Shuttle Lite, but robotic and run by the military, not NASA. This has the Chinese worried, and they are not being quiet about their fears.
Six passengers? Do tell. I believe I speculated that this capability might be useful. When you need to seize the high ground, sometimes it has to be literally taken and held. We'll need to rephrase that expression "boots on the ground." Aim high, indeed.
No wonder the Chinese are worried.