Top-secret X-37B space plane will execute 'never-before-seen maneuvers' on its descent to Earth

A secret, experimental space plane will be performing a new kind of specialized brake maneuver as it returns to Earth’s atmosphere, the U.S. Space Force announced.

The X-37B is a secret, remotely operated spacecraft designed by Boeing for unknown purposes in service of the U.S. Department of Defense (DOD). Although its missions are classified, we know the ship previously acted as a platform to test the effects of solar radiation on seeds. It may also test novel military surveillance technology, according to reports in the The New York Times and The Guardian.

In its latest maneuver, the X-37B will engage in "aerobraking" — a series of controlled descents into Earth's atmosphere, in which the craft purposefully uses aerodynamic drag to change its orbit without consuming too much fuel.

"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," said Secretary of the Air Force Frank Kendall, in a statement.

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The aerobraking tests would allow the X-37B to rapidly and unpredictably change its orbit, which could temporarily prevent it from being tracked by other nations. In 2019, Former United States Secretary of the Air Force Heather Wilson told attendees of the Aspen Security Forum that the X-37B could perform this maneuver “on the far side of the Earth from our adversaries”, which prevents them from accurately predicting the trajectory of the spacecraft, per Military.com.

The X-37B began its seventh mission (OTV-7) in December 2023 after launching a SpaceX Falcon Heavy rocket. It is being overseen by both the Space Force and the U.S. Department of the Air Force Rapid Capabilities Office — an Air Force office that exists to push the limits of military technology.

At the time of its launch, mission parameters included "operating the reusable spaceplane in new orbital regimes," according to representatives from the U.S. Space Force. During OTV-7, the spacecraft has operated in a highly elliptical orbit, an oval-shaped orbit that carries the spaceplane between 620 miles (1,000 kilometers) or less of Earth's surface and more than 22,210 miles (35,750 km) away. The X-37B has previously been observed as low as 185 miles (300 km) above Earth.

Facts about the X-37B, which has been in testing for 15 years, are few and far between. The craft is remotely controlled, measures about 29 feet (9 meters) long and 9.5 feet (3 m) tall and can orbit from just a few hundred to many thousands of miles above Earth after launching via rockets. It resembles a miniature space shuttle and is reusable as it can land on a runway at the end of each mission.

An exception to this is the X-37B’s service module, in which some of the spacecraft's technical equipment is stored, which is due to be ejected from the craft before it lands. The Space Force noted this will be done in line with international standards on reducing space debris, so the equipment won’t continue to orbit Earth and worsen the space junk problem.

The X-37B can remain in space for years on end, having orbited Earth for 908 days in its OTV-6 flight, with onboard solar panels enabling it to recharge its batteries.

The U.S. Space Force has vaguely outlined the objectives for X-37B's former missions including "operating in new orbital regimes, experimenting with space domain awareness technologies and investigating the radiation effects to NASA materials." The Space Force also referenced experiments in transmitting solar energy from space to the ground using the X-37B.

For OTV-6, the mission parameters also included "experimenting with space domain awareness technologies" — systems used to detect and track objects orbiting Earth. Given the spacecraft’s long orbit, it could potentially keep tabs on satellites in Earth's orbit, including those of adversaries.