X-37B

The unmanned X-37B Orbital Test Vehicle took off from Cape Canaveral in late April, and it launched a frenzy of speculation about its mission. Begun in 1999 as a NASA project to develop a reusable space plane, it now is under the auspices of the U.S. Air Force, which made cryptic reference to the prototype X-37B leading to quick reactions to "warfighter needs."

The more fevered imaginations have envisioned the vehicle as a potential weapon itself; more measured reaction has suggested that the X-37B could serve as a sort of quick-reaction surveillance satellite. The 29-foot-long space plane, much smaller than the space shuttles, can stay in orbit for up to nine months.

This photo shows the X-37B against the backdrop of the fairing that would encapsulate it for liftoff atop an Atlas V rocket.