The second time was the charm for SpaceX as it was able to launch the X-37B military spaceplane onboard its Falcon Heavy rocket. Liftoff of the USSF-52 mission from NASA’s Kennedy Space Center occurred at 8:07 p.m. EST (0107 UTC) on Thursday at the opening of a ten-minute launch window.
The launch came after SpaceX and the U.S. Space Force had to delayed the mission from Dec. 11 due to “a ground side issue.” The Falcon Heavy was returned to its hangar on Dec. 14 with SpaceX no longer saying the vehicle remained ‘healthy’ in its social media posts.
SpaceX didn’t elaborate on the reason or reasons for the delay, but multiple sources tells Spaceflight Now that at least one engine had to be replaced on the Falcon Heavy rocket. A second static fire test was deemed unnecessary, which allowed SpaceX to get in another launch attempt before the end of the year and reschedule the mission for Dec. 28.
Onboard the three-core rocket was the X-37B Orbital Test Vehicle (OTV). This was the seventh launch in the program’s history since 2010 and the fourth flight of Vehicle 2 the second of two craft in the OTV fleet.
About 8.5 minutes after liftoff, the two Falcon Heavy side boosters, tail numbers B1064 and B1065, returned to Landing Zone 1 and 2 at Cape Canaveral Space Force Station. Those watching the launch in person may have heard a pair of sonic booms as they reenter the atmosphere.
These boosters made their fifth flight to date after launching the USSF-44, USSF-67, Jupiter-3 and Psyche missions previously. They will be launched one more time in October 2024 to launch NASA’s Europa Clipper spacecraft to the Jovian moon of the same name.
The Falcon Heavy rocket for this mission rolled back out to the pad at Launch Complex 39A Wednesday morning. This marked the second time SpaceX will launch the X-37B after previously giving it a ride on a Falcon 9 on the fifth OTV mission in September 2017.
All other previous mission were launched using United Launch Alliance’s Atlas 5 501 rocket from neighboring pad 41.
More information about the X-37B and the importance of the mission for both SpaceX and the U.S. Space Force