This post is also available in: heעברית (Hebrew)

The secretive US Air Force Boeing X-37B orbital unmanned spacecraft has recently landed at the Kennedy Space Center Shuttle Landing Facility following an extended 717-day long mission in earth orbit (the earth’s route). The specifics of the mission and the role of the X-37B remain classified.The spacecraft landed using normal aircraft-style landing gear, similar to the now-retired manned space shuttle program. Despite its classified mission, video of the landing has been widely publicized.

According to, since the first flight of the system was seven years ago, it’s reasonable to assume the program has moved beyond the developmental stage and may now be an operational project. This has created substantial speculation about what the role of the X-37B may be.

Three main theories stand out. The first theory – the X-37B is a space-based weapons platform. The spacecraft is pre-deployed into orbit armed with some type of weaponized re-entry vehicle that could be released over or near a specific target. It may also be a weapons delivery vehicle deployed in defense of space-based commercial assets such as the GPS satellite constellation. This theory is debunked by most analysts.

Secondly, and most plausibly, the spacecraft may be a platform for gathering intelligence. This could include signals intelligence such as activities of communications and surveillance satellites, both civilian and military. With approximately 2,271 satellites in orbit around the earth at various altitudes performing a wide variety of functions this theory tends to be the most realistic. It may also be ground mapping radar and other surveillance mediums. Since the large internal payload bay of the X-37B, about the size of the interior of a small general aviation aircraft such as a Cessna Caravan, is interchangeable the spacecraft could be “mission adaptive”, meaning it could be reconfigured for various types of surveillance. That this last mission was so long in duration suggests the X-37B may have had a means of transmitting intelligence from space back down to earth, somehow beyond the capabilities of existing space-based surveillance platforms like satellites.

Lastly, and most unlikely, the X-37B remains a research project. It could potentially be a test bed for deploying satellites and servicing them robotically in space, releasing new orbital packages into space or any number of other roles not yet performed operationally. Given the duration and investment into the program along with the operational security surrounding it this theory seems least likely.

Several techno-thriller writers have included the X-47B in their fictional story lines as both an ISR platform (intelligence, surveillance, reconnaissance) and a weapons delivery vehicle.

Whatever the role of the secret X-37B project the continuing operation of the spacecraft certainly verifies it is up to something big.