Rather than launch from a United Launch Alliance (ULA) Atlas V or SpaceX Falcon 9 as it has done in the past, the seventh takeoff of the US Space Force's reusable X-37B spaceplane will make use of a Falcon Heavy rocket.

"The X-37B Mission 7 will launch on a SpaceX Falcon Heavy rocket for the first time, designated USSF-52, with a wide range of test and experimentation objectives," Space Force confirmed last night.

Those tests include operating the X-37B in new orbital regimes, experimenting with future space domain awareness technologies, and investigating the effects of radiation on materials, including plant seeds.

Program director Lt. Col. Joseph Fritschen said mission 7 will use the flight-proven service module that mounts to the spaceplane.

Space Force did not give any indication on why it is launching from a Falcon Heavy. Five of the last missions for the spaceplane were aboard the Atlas V. The fifth mission, launched in 2017, used a Falcon 9.

Missions aboard the X-37B are typically vague in details as the spaceplane has a history of secrecy.

A Falcon Heavy, however, is capable of lifting a heavier payload. It can put nearly 141,000 lbs (63.9 metric tons) into low Earth orbit or a little over 58,000 lbs (26.3 metric tons) into Geosynchronous Transfer Orbit (GTO). Comparatively, the Falcon 9 can lift just over 50,000 lbs (22.7 metric tons) into LEO or over 18,000 lbs (8.2 metric tons) to GTO. The Atlas V can hoist a little over 41,500 lbs (18.8 metric tons) to LEO and 19,600 lbs (8.9 metric tons) to GTO.

Not including the service module, the X-37B has a maximum takeoff weight of 11,000 lbs (4.9 metric tons).

Self-described "infamous YouTube rocket scientist" Scott Manley reminded the internet that the mission's solicitation required 6,350 kg (14,000 lbs) to GTO, which is heavier than previous X-37B launches.

Because of the spaceplane's journey to a higher orbit for the first time, the vehicle will be under unique stresses, noted Manley, including both speed and exposure to heat.

USSF-52 was originally intended to be launched in 2021 but was delayed by payload and range availability. The $130 million contract was awarded to SpaceX in June of 2018.

The current launch date is December 7 from Kennedy Space Center. X-37B's last mission was completed when it landed November 2022 after setting a record of 908 days in orbit. ®

https://www.theregister.com//2023/11/09/space_force_spaceplane/