By BlueShift | 2025-03-17

After more than a year in orbit, the US Space Force (USSF)'s unmanned X-37B Orbital Test Vehicle (OTV-7) touched down earlier this month at Vandenberg Space Force Base, California.

Its latest spaceflight mission closed out at 434 days, a duration equal to a bit less than half of its 908-day-long previous -- and longest -- mission.

"Mission 7 broke new ground by showcasing the X-37B's ability to flexibly accomplish its test and experimentation objectives across orbital regimes," Chief of Space Operations Gen. Chance Saltzman said in a statement March 7 following the landing.

The small, uncrewed space plane measures just under 9 meters long and has a wingspan of 4.6 meters. Each space plane weighs just about 5,000kg.

The craft launches atop rockets but deorbits and lands horizontally like conventional aircraft.

This seventh mission marked the first time that the X-37B was launched from a SpaceX Falcon Heavy Rocket into a Highly Elliptical Orbit, rather than operating solely in Low Earth Orbit.

The X-37B undergoes continuous upgrades, according to Michelle Parker, Boeing's vice president for space mission systems.

"Even though it may look the same, a lot of the innards have been upgraded and then can continue to fly for a significant amount of time," Parker told Aviation Week on February 21.

For example, the vehicle is on its second generation of batteries and third generation of solar cells. Boeing also developed a new collision avoidance system ahead of OTV-7, Parker said.

Aerobraking maneuvers on display

Since launch of the first mission in 2010, many details of the X-37B program have remained confidential. However, the USSF has gradually shared information about the mission's role in developing new concepts for space operations.

In a press release announcing the X-37B's return to earth, USSF highlighted that the space plane demonstrated novel aerobraking maneuvers, a technique that leverages atmospheric drag to change orbit without significant fuel expenditure.

The aerobraking's in-flight agility affords the USSF significant tactical advantage. The orbital changes caused by the maneuver lack the typical visual propulsion signatures that might be detected by adversaries.

"Mission 7's operation in a new orbital regime, its novel aerobraking maneuver and its testing of space domain awareness experiments have written an exciting new chapter in the X-37B program," X-37B Program Director Lt. Col. Blaine Stewart said in a statement.

"Considered together, they mark a significant milestone in the ongoing development of the US Space Force's dynamic mission capability."

"This novel and efficient series of maneuvers demonstrates the Space Force's commitment to achieving groundbreaking innovation as it conducts national security missions in space," Air Force Secretary Frank Kendall said in a statement October 10 announcing the start of aerobraking testing.

The mission contained payloads for both NASA and the Department of Defense and conducted data collection for orbital maneuvering.

These tests will help inform understanding of how different sensors and tracking systems perform while scientists monitor spacecraft maneuvers across orbital regimes.