Secret Spaceplane has been in orbit for 500 days - Mystery Mission?

The Air Force’s secret space plane has been up in orbit for nearly 500 days—a space endurance record. But nearly a year and a half into the mission, the Pentagon still won’t say what the X-37B is doing up there, or when it might come back.

The U.S. Air Force boosted the robotic X-37B atop the nose of an Atlas-5 rocket in December 2012. Since then it’s orbited the Earth thousands of times, overflying such interesting places as North Korea and Iran.
Similar to the Space Shuttle in appearance, the diminutive X-37B is about a quarter the size of the old shuttles. But there are major differences. Lacking a crew, the spacecraft has no cockpit windows. The X-37B has a payload bay about the size of a pickup truck bed

...Another rumor is that the X-37B can, like supervillian Ernst Blofeld’s giant clamshell satellite in You Only Live Twice, saddle up to the satellites of other nations and mess with them. Though theoretically possible, the X-37 would have to be launched into an orbit similar to the target’s, and the X-37B’s size makes it easy to track. Even amateur satellite spotters can track the X-37B, and it would be obvious to everyone who had stolen a satellite.

The most interesting—but least likely—rumor is that the X-37B is some kind of orbital bomber, capable of nailing targets from on high. There’s not a whole lot of evidence to back that theory up.

[link to uk.news.yahoo.com (secure)]