Secretive X-37B Robot Space Plane Moves to Launch Pad
A United Launch Alliance Atlas 5 rocket with the Air Force's X-37B Orbital Test Vehicle (OTV) - inside the bulbous nose cone - the rolls out to its Space Launch Complex-41 launch pad at the Cape Canaveral Air Force Station in Florida on April 21, 2010.
Credit: Pat Corkery/United Launch Alliance.

An unmanned rocket rolled out to its seaside launch pad in Florida today carrying a secretive robotic X-37B space plane for the United States Air Force ahead of a planned Thursday launch.

The Air Force plans to launch the X-37B space plane on a demonstration flight that could last months. Liftoff is set for Thursday night between 7:52 p.m. and 8:01 p.m. EDT (2352-0001 GMT) from the Cape Canaveral Air Force Base in Florida. [X-37B spacecraft photos.]

The United Launch Alliance, which is providing the Atlas 5 rocket launching X-37B into space, rolled the booster out to Space Launch Complex-41 at the Air Force Station at 11 a.m. EDT (1500 GMT) today.

The robotic X-37B space plane looks like a miniature space shuttle and even has a small payload like NASA's orbiters. It weighs about 11,000 pounds and is just over 29 feet in length. It stands slightly more than 9 1/2 feet in height and has a wingspan just over 14 feet across.

But unlike its bigger space shuttle brethren, the X-37B is designed to fly unmanned and remain in orbit for up to 270 days. NASA shuttle missions typically carry up to seven astronauts and last around two weeks.

Air Force officials have kept the details of this X-37B mission ? called the Orbital Test Vehicle ? and the spacecraft's cost secret.

Gary Payton, the U.S. Air Force Deputy Under Secretary for Space Programs, told reporters Tuesday that the mission will test a new batch of reusable technologies, including new silica heat shield tiles to protect the space plane from atmospheric re-entry, as well as "other technologies that are sort of one generation beyond the shuttle."

Payton said the X-37B is designed to re-enter and land autonomously, without any direction from mission controllers after starting its descent from orbit. The mini-shuttle is expected to land at the Vandenberg Air Force Base in California at the end of its debut test flight, he added.

The X-37B was built by Boeing's Phantom Works division in Seal Beach, Calif. The Air Force has already ordered a second Orbital Test Vehicle, but whether it launches in 2011 as planned hinges on the performance of the upcoming test flight, Air Force officials said.