A U.S. Air Force robotic space plane continues to maneuver in Earth orbit, according to the latest observations from skywatchers. The reusable space drone has been carrying out tasks using a suite of classified sensors and may be nearing its mission's end, according to comments from Air Force officials.

The spacecraft is the Air Force's X-37B space plane, also known as the Orbital Test Vehicle 1, which launched on its maiden flight on April 22 atop an Atlas 5 rocket.

The winged orbiter's mission has been shrouded in secrecy, but Air Force officials have said it was built for 270-day spaceflights, suggesting that it may be in the flight homestretch and preparing to make an atmospheric re-entry and landing – all on autopilot. [Video of the X-37B in space]

Official details regarding the space plane's whereabouts, its classified payload and projected landing date are scarce — more mum than informative.

"Nothing new," said U.S. Air Force Major, Tracy Bunko, a spokeswoman for the mission at the Pentagon's Air Force press desk.

"The first flight of the X-37B/OTV-1 is ongoing and continues to focus on checking out the on-orbit performance of the vehicle and proving the technologies required for long-duration, re-usable space vehicles with autonomous re-entry and landing capabilities," Bunko told SPACE.com.

Bunko said that after the X-37B test objectives are satisfied, "we look forward to a successful re-entry and recovery at Vandenberg Air Force Base, California."

No landing date has been scheduled, she added.

This SPACE.com X-37B graphic illustrates some details of the space plane, its solar array power plant, and its relative size.