Boeing's Military Space Plane Just Slammed on the Brakes in Orbit

Aerobrake Things

The US military's top secret X-37B space plane, which has been orbiting the Earth since December 2023 on its current mission, has slammed on the brakes.

As detailed in a Boeing Space video, the plane has started "performing advanced aerobraking maneuvers," which are designed to lower its currently "highly elliptical orbit."

The goal is to "safely dispose of the service module components in accordance with recognized standards for space debris mitigation" — without having to burn copious amounts of fuel to change orbit.

It's a simple idea that could greatly extend the amount of time a spacecraft could spend in space: using the friction generated by plowing through the outer reaches of the Earth's atmosphere instead of using up propellant.

"When we aerobrake, we utilize atmospheric drag to effectively step down our apogee one pass at a time until we get to the orbital regime that we want to be in," Boeing engineer John Ealy explained in the video. "When we do this, we save enormous amounts of propellant, and that's really why aerobraking is important."

https://twitter.com/BoeingSpace/status/1852470814383214848

Belly Cut

Renders of the maneuver shared by Boeing show the spaceplane's underbelly glowing red and orange as it heats up, not unlike the kind of heat we saw being generated during SpaceX's most recent Starship test flight.

Apart from its most recent stunt, we know essentially nothing about the X-37B and its greater purpose. The spaceplane, which is in its second generation, launched for the fourth time on SpaceX's Falcon Heavy rocket in December 2023 as part of the Orbital Test Vehicle-7 (OTV-7) mission. Its highly elliptical orbit means that it spent parts of each rotation well above geosynchronous orbit before screaming past our planet at a much closer distance.

"X-37B missions have continuously advanced our nation's space capabilities by testing new technologies that reduce risk and inform our future space architectures," said program director for Boeing's Experimental Systems Group Holly Murphy in the video.

Secretary of the Air Force Frank Kendall also hailed the aerobraking maneuver as a "groundbreaking innovation" in a statement last month.

"This first of a kind maneuver from the X-37B is an incredibly important milestone for the United States Space Force as we seek to expand our aptitude and ability to perform in this challenging domain," Chief of Space Operations general Chance Saltzman added at the time. "The success is a testament to the dedication and perseverance of the team."

More on the space plane: The Space Force's Top-Secret Spaceplane Is About to Do a Sick Stunt