For example, Air Force officials have revealed that its payloads include the Advanced Structurally Embedded Thermal Spreader experiment (ASETS-II), which is measuring how oscillating heat pipes and certain electronics perform in the space environment. 

So that can’t be done on the ISS?

BS meter is pegged.

What takes 700 plus days? I’ll take a wild guess and say one of the missions is spying…on you.

https://www.space.com/x-37b-military-space-plane-otv5-700-days.html

By Mike Wall

The U.S. Air Force’s X-37B military space plane has now been circling Earth for 700 days, just a few weeks shy of the vehicle’s spaceflight-duration record.

The robotic X-37B launched on its fifth and latest mission, known as Orbital Test Vehicle 5 (OTV-5), on Sept. 7, 2017. And the reusable spacecraft, which looks like a miniature version of NASA’s space shuttle, has been zipping around our planet ever since.

Exactly what the X-37B is doing up there remains a topic of much speculation; the solar-powered spacecraft’s missions, and most of its payloads, remain classified. The Air Force tends to talk about the X-37B program in general terms, stressing that the space plane tests technologies for future reusable spacecraft and takes experiments up to space and back.

We do know a few details about OTV-5, however. For example, Air Force officials have revealed that its payloads include the Advanced Structurally Embedded Thermal Spreader experiment (ASETS-II), which is measuring how oscillating heat pipes and certain electronics perform in the space environment…

Be seeing you