Lockheed Martin SR-72 Lockheed Martin SR-72 The Lockheed Martin SR-72 is an American hypersonic UAV concept intended for intelligence, surveillance and reconnaissance. Lockheed Martin privately proposed it to succeed the retired Lockheed SR-71 Blackbird. The SR-71 Blackbird retired in 1998, leaving what was considered a coverage gap between surveillance satellites, manned aircraft, and unmanned aerial vehicles for intelligence, surveillance and reconnaissance (ISR) and strike missions. With the growth of anti-satellite weapons, anti-access/area denial tactics, and counter-stealth technologies, a high-speed aircraft could penetrate protected airspace and observe or strike a target before enemies could detect or intercept it. The proposed reliance on extremely high
Lockheed Martin A2100 later increased to 2.55 m. The liquid apogee engine uses hydrazine fuel from the central tank along with nitrogen tetroxide oxidizer from two flanking tanks of 0.54 m diameter and up to 1.65 m long. Orbit maintenance is performed by the small hydrazine motors and ion thrusters. The maximum propellant supply (with the largest tanks at 95% fill factor) are 1368 kg of hydrazine fuel and 627 kg of nitrogen tetroxide oxidizer. According to Moog-ISP, the A2100 platform uses its LEROS bipropellant Liquid Apogee Engine. Lockheed Martin A2100 The A2100 is a communications satellite spacecraft model made by Lockheed Martin