The United States Air Force's X-37B program is readying its next robotic mini-shuttle for launch, this time atop a SpaceX Falcon 9 rocket.

The liftoff is scheduled to take place in early September, according to media reports.

Capt. Annmarie Annicelli, a U.S. Air Force spokeswoman, told Inside Outer Space: "At this time, I do not have the launch date to release." [The Mysterious X-37B Space Plane: 6 Surprising Facts]

The upcoming X-37B mission — which is known as Orbital Test Vehicle-5 (OTV-5) — will lift off from Launch Complex 39A at NASA's Kennedy Space Center in Florida.

Shuttle look-alike 

The Air Force is known to own two reusable X-37B space planes, which were built by Boeing. The vehicles look like miniature versions of NASA's now-retired space shuttle orbiter; each X-37B is 29 feet (8.8 meters) long and 9.6 feet (2.9 m) tall, and each has a wingspan of nearly 15 feet (4.6 m).

The space drone has a payload bay about the size of a pickup truck bed that can be outfitted with a robotic arm. It has a launch weight of 11,000 lbs. (4,990 kilograms) and is powered on orbit by gallium- arsenide solar cells with lithium-ion batteries.

The X-37B program is managed by the Air Force Rapid Capabilities Office to perform risk reduction, experimentation and concept of operations development for reusable space vehicle technologies.

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