Lessons from Recent Programs

Transatmospheric vehicles (TAVs), with aerodynamic properties similar to conventional aircraft, have the promise of flying into space and delivering payloads into low earth orbit (LEO). A key distinguishing feature between TAVs and aircraft is propulsion. Jet engines or pure air-breathing propulsion systems cannot provide the thrust levels needed to ascend into space. Traditional rockets overcome this limitation by carrying their own oxidizer. However, traditional rocket boosters are expended after use. TAVs would be Reusable Launch Vehicles (RLVs) capable of returning to earth and flying again after refurbishment and refueling.1 Because of their reusability, TAVs could potentially launch payloads into orbit or into suborbital trajectories at much lower costs than expendable launch vehicles.