X-37B Departs Atop Falcon 9 for Secret Mission

The U.S. Space Force's secretive X-37B spaceplane is back in Earth orbit for a classified mission and technology demonstrations.

Out of Launch Complex 39A in Florida at 03:50 am Universal Coordinated Time, a Falcon 9 began its journey into Earth orbit for the U.S. Space Force's USSF-36 mission. First-stage ascent was nominal, with the second-stage starting up cleanly along with separation of the two fairing halves, but not long after, live feeds of ascent were cut at the request of the Space Force.

Supporting USSF-36's trek to orbit was booster B1092 for its sixth flight, landing back at Landing Zone 2 in Cape Canaveral afterwards. This booster has previously supported the launches for NROL-69, CRS-32, GPS III-7, and two Starlink missions. Additionally, this was the third time SpaceX has supported X-37B missions.

Riding Falcon 9 into orbit was X-37B Vehicle 1, made by Boeing, which also produced its twin. The spaceplane is around one-fourth the scale of the Space Shuttle and, unlike the Space Shuttle, launches inside a conventional rocket's fairing. But, Much like the Space Shuttle, the majority of the craft's stowage space is contained within a horizontally-laid payload bay, with hinged doors allowing for exposure to the vacuum of space and deployment of free-flying payloads.

Owing to its military nature, much of what takes place from the time X-37B lifts off the ground on its launch vehicle to the moment it touches down on the runway at the end of its mission is extremely unclear.

The X-37B's eighth mission is set to complete various objectives for the U.S. military, including technology demonstrations. Two technology tests are known to be onboard and are a laser communications demonstration and a quantum inertial sensor planned to measure the spaceplane's acceleration and rotation.

Testing of laser communications during the mission is set to improve the resilience, security, and efficiency of American space-based communications through low Earth orbit satellite networks (i.e., Starlink and Starshield). Laser communications are also being pushed by the U.S. Space Force as key to next-generation military communications.

Meanwhile, tests of the quantum inertial sensor could broadly benefit space navigation, providing accurate positioning in cislunar space and beyond. The test demonstration onboard the X-37B itself will measure the accuracy of unaided navigation in orbit. Commander of the Colorado-based Space Delta 9, Colonel Ramsey Horn, spoke on the military significance of the quantum sensor demonstration, stating:

"[The mission]'s quantum inertial sensor demonstration is a welcome step forward for operational resilience in space. Whether navigating beyond Earth based orbits in cislunar space or operating in GPS-denied environments, quantum inertial sensing allows for robust navigation capabilities when GPS navigation is not possible."

It is unknown when the X-37B will return to Earth to end its mission, usually spending multiple months in orbit. When it does, the spaceplane will land on a runway at either the Kennedy Space Center or Vandenberg Space Force Base.

Since 2010, the two X-37B spaceplanes have performed missions in orbit seven times, largely speculated to be reconnaissance missions in low Earth orbit. In its previous mission, launched atop a Falcon Heavy, the spaceplane flew around high Earth orbit for the first time, performing aerobrake maneuvers before its return as well.