Boeing’s unmanned X37B Spaceplane–which conveniently doesn’t need exit doors–performed some aerodynamic maneuvers in space, using the minimal atmosphere of low orbit to slow the craft and reposition its orbit.
“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,” an engineer from Boeing Space said, according to IFLScience. Essentially what that means is that the X37B space plane positioned its underside surfaces to hit the atmosphere to slow the ship, allowing it to change the course of its orbit.