'Baby space shuttle' awaits Tuesday launch aboard Atlas V rocket

By Greg Pallone, Reporter
Last Updated: Monday, December 10, 2012, 2:51 PM EST

We are less than 24 hours away from the next launch of an Air Force secret space plane from Cape Canaveral Air Force Station, if the weather holds.

This will be the third launch of the X-37B unmanned space plane and as with the other missions, it's under a cloak of secrecy.

There are currently two of them nicknamed “baby space shuttles” built by Boeing.

The pair of spacecraft are much smaller than a shuttle.

They are 29-feet-long and 15-feet-wide. Its payload bay is comparable to the size of what a small truck can haul. Whatever payload is on board is under wraps.

The craft will lift off on a United Launch Alliance Atlas V. A fuel leak delayed the original October mission.

The previous spacecraft orbited Earth for 469 days before landing at California's Vandenberg Air Force Base.

It is thought eventually these space planes may land at the Kennedy Space Center.

launch is set for 1:03 p.m. Tuesday. The launch window extends to after 6 p.m. There is only a 30 percent chance of favorable weather conditions for liftoff.