[Elv13]

It actually make some sense if their official explanation for the purpose of the vehicle is true. If the main reason for the X-37b is to bring material to orbit and study the long term effect of being in space, then going higher make sense.

In an elliptical orbit, you can cross the Van Hallen belt and magnetic fields over and over again. Then after a couple years return those samples to earth for study. This gives you valuable data to build better satellites in the future.

For examples, the gyros flywheel on the Hubble and it's sibling spy telescope failed over and over until they realized the radiations caused some arcing in the bearings which degraded them much faster than predicted. When you spend billions on individual satellites, this isn't the kind of thing you want to discover in orbit.

[jamiek88]

Yes and some of these satellites cost more than an aircraft carrier.

Having the x37 try out new materials and parts etc is a great capability that is obviously needed if the US is to maintain its technical superiority.