For the first time, the U.S. military’s secret spacecraft X-37B has tested aerodynamic braking maneuvers in Earth’s orbit, as revealed by Boeing Space in a video.
Simulation of the X-37B spacecraft using aerodynamic braking due to Earth’s atmospheric drag. (Photo: Boeing Space).
Typically, when changing orbits, satellites utilize propulsion engines and require fuel. This means that each satellite can only perform a limited number of burns before needing to refuel or be deorbited. The U.S. Space Force stated that aerodynamic braking uses friction and drag from Earth’s atmosphere to lower an orbit while minimizing fuel consumption, according to Live Science on November 10.
In the video, a Boeing representative noted that this maneuver will help change the altitude of the X-37B. After transitioning from a high elliptical orbit to a lower circular orbit, the spacecraft will subsequently release its service module components. These components will remain in orbit for a significantly shorter time than if released from a high orbit, thereby reducing space debris.
(Video: Boeing Space).
John Ealy, an engineer at Boeing, explained that when using aerodynamic braking, they leverage atmospheric drag to gradually reduce the apogee until reaching the desired orbit. “By doing this, we save a significant amount of fuel, which is why aerodynamic braking is important,” John Ealy stated in the video.
Boeing’s video on the aerodynamic braking maneuver shows the X-37B, similar to an aircraft, changing its orientation and facing direction compared to its orbital trajectory, with its “belly” flatly directed forward while the nose points upward, turning away from Earth. The images also depict the spacecraft’s broad, flat underside glowing orange due to the heat generated from the drag (a form of friction) created by Earth’s atmosphere, causing it to slow down.
“This first maneuver of the X-37B is an extremely important milestone for the U.S. Space Force as we seek to expand operational capabilities in this challenging domain,” the leader of the U.S. Space Force praised the X-37B team for testing this novel maneuver in a statement.
The most recent mission of the X-37B, known as OTV-7 (short for “Orbital Test Vehicle-7”), witnessed the spacecraft being launched on SpaceX’s Falcon Heavy rocket for the first time, placing it into an elliptical orbit at an unspecified altitude.
Like all previous X-37B flights, very little information is known about OTV-7 aside from the fact that the mission is testing the effects of space radiation and technology for “space domain awareness.” This can be understood as new technology to assist the U.S. Space Force in tracking orbital traffic and what other spacecraft are doing in Earth’s orbit.
After the aerodynamic braking maneuver, the X-37B will continue with its testing objectives. The spacecraft will then deorbit and land like the previous six missions.
The X-37B is an unmanned spacecraft owned by the U.S. Air Force. The Air Force has two X-37B vehicles for alternating use and has conducted six missions since 2010. The current flight of the X-37B marks its seventh mission. The X-37B was first launched on an Atlas V rocket from United Launch Alliance in 2010.
