The Air Force’s 30th Space Wing announced that the plane landed at Vandenberg Air Force Base in California on October 17, after exactly 674 days in space.

X-37B Space Plane Returns From Top-Secret Mission

“The 30th Space Wing and our mission partners, Air Force Rapid Capabilities Office, The Boeing Company (NYSE:BA), and our base support contractors, have put countless hours of hard work into preparing for this landing and today we were able to see the culmination of that dedication,” Colonel Keith Balts, 30th Space Wing commander, stated. “I’m extremely proud of our team for coming together to execute this third safe and successful landing. Everyone from our on console space operators to our airfield managers and civil engineers take pride in this unique mission and exemplify excellence during its execution.”

X-37B Space Plane’s specifications

First of all let’s talk about what we do know. The Boeing-built craft just returned from a third mission to space, and resembles a miniature space shuttle at 9.5 feet tall and 29 feet long. It has a wingspan of 15 feet, and weighs around 5.5 tons.

The unmanned spacecraft took up orbit 180 miles above Earth, but what it was doing up there remains a mystery. The dimensions of the vehicle means that there is only room for avionics equipment, fuel, and a cavity about the size of a truck bed whose cargo is not known.

X-37B Space Plane: Top-secret mission

Those that have been speculating as to the function of the X-37B are really just searching in the dark. Any requests for comment from the Air Force have been firmly rebuffed.

Assorted rumors include the testing of classified radio hardware or radiation-resistant materials, collection of data for research or defense purposes, or use as a distraction in the geopolitical sphere, providing reasons for China and other global rivals to worry about the militarization of space.

As intriguing as the X-37B may appear, I would not recommend holding your breath on the Air Force releasing more information any time soon.