On Thursday, December 28th at 8:07 PM, Eastern Time, SpaceX’s Falcon Heavy lifted off carrying the secretive X-37B spaceplane as part of the USSF-52/OTV-7 mission for the United States Space Force. Delayed several times due to inclement weather across the Eastern seaboard and other unspecified issues with the launch vehicle, the mission was finally able to get underway Thursday night – providing a spectacular show for those in attendance.
After liftoff, the vehicle pitched downrange and rolled to the correct azimuth, before its two side boosters finished their job and returned to Cape Canaveral for a dual RTLS landing on Landing Zones 1 and 2. SpaceX later turned the range around to launch Starlink 6-36 atop Booster 1069, making its 12th flight since it joined the fleet. The second flight of the day lifted off at 11:01, making it the shortest modern turnaround since Psyche and Starlink 6-27 in October – clocking in at 2 hours, 54 minutes.
The X-37B Orbital Test Vehicle (OTV) has now flown 7 times since its debut in 2010; Thursday’s launch being the first time it has flown aboard the Falcon Heavy rocket. SpaceX launched the OTV-5 mission in September 2017 on a Falcon 9 Block 4. The other five flights of the spaceplane used the United Launch Alliance Atlas V 501 rocket. The duration of these missions has varied extremely, some of these missions lasting well over 900 days. The previous flight of the X-37B holds the record, with OTV-6 clocking in at a total of 908 days in orbit.
The nature of the mission, as is the case with X-37B flights, is not entirely clear – however the use of the heavy lift Falcon Heavy suggests that this mission differs greatly from previous flights in terms of its target orbit. In a statement, the USSF said: “The use of a Falcon Heavy rocket will expand the X-37B flight envelope, launching into a new orbital regime, and enabling unique experimentation opportunities for the X-37B.” Dr. Marco Langbroek from TU Delft has used available NOTAMs to infer that the mission will be targeting a highly eccentric, 74º orbit after a significant dogleg maneuver is performed over continental Europe.
While the mission’s orbit is not disclosed, it is understood that a series of payloads both civilian and military will be flown onboard the spacecraft. A comprehensive list has not been released, but an Air Force press statement stated that the payloads on board “will expand the United States Space Force’s knowledge of the space environment by experimenting with future space domain awareness technologies. These tests are integral in ensuring safe, stable, and secure operations in space for all users of the domain.” On the civilian side, NASA’s Seeds-2 mission will investigate the harsh in space radiation environment for future deep space exploration.
Regardless of the precise nature of the mission, it is clear that the spaceplane remains a tremendous asset to the Department of Defense, and represents cutting edge work in defense development. “The X-37B continues to equip the United States with the knowledge to enhance current and future space operations. X-37B Mission 7 demonstrates the USSF’s commitment to innovation and defining the art-of-the-possible in the space domain,” said Gen. B. Chance Saltzman, the Chief of Space Operations, in a statement prior to launch.
With the mission successfully underway, only time will tell where the mysterious spaceplane has ended up. Amateur satellite trackers have identified the spacecraft in orbit before, which may present itself as a challenge with the new orbital characteristics of this mission. With the 7th mission of the X-37B underway, those still on Earth can only wonder when this mysterious undertaking will draw to a close.