Little may be known about the U.S. Air Force's (USAF) X-37B spacecraft, but it did have a successful launch to kick off its fourth low-orbit mission.
According to the New York Times, the unmanned craft first launched in April 2010 amid speculation the government was testing some sort of space-based weapon. The Pentagon reportedly said this was not the case, but would not elaborate on the nature of the mission.
The same can be said for Wednesday's launch from the Cape Canaveral Air Force base. The USAF would not say what was aboard the X-37B, a Boeing-built spacecraft that took off on an Atlas V rocket.
"We are excited about our fourth X-37B mission," Randy Walden, the director of the Air Force Rapid Capabilities Office, said in a statement last month. "With the demonstrated success of the first three missions, we're able to shift our focus from initial checkouts of the vehicle to testing of experimental payloads."
What is known about the mission is that NASA will be testing the reactions of about 100 materials when put in space. The space agency is also looking to see how effective the spacecraft's electric thrusters are, as they could potentially use them on a future space exploration mission to Mars.
"The test mission furthers the development of the concept of operations for reusable space vehicles, and fine-tunes technical parameters for an affordable, reusable space vehicle," Capt. Christopher M. Hoyler, a USAF spokesman, told the Times.
OTV-4, as the mission is formally known, may not be entirely secretive, but it is far off the routine International Space Station resupply missions.
"OTV missions allow us to examine a payload system or technology in the environment in which it will perform its mission," Hoyler told Space.com. "The unique aspects of the OTV allow us to mature these new technologies and inspect them following the de-orbit sequence."
