Lockheed Martin SR-72 have the same range, with entry into service by 2030. The SR-72 follows the US Air Force's hypersonic road map for developing a hypersonic strike weapon by 2020, and a penetrating ISR aircraft by 2030. At the time of the concept's unveiling, Lockheed Martin had engaged in talks with government officials, but has not secured funding for the demonstrator or engine. On 13 November 2013, Air Force Chief of Staff General Mark Welsh revealed that the service was interested in the SR-72's hypersonic capabilities, but had not spoken with Lockheed Martin about the aircraft. Its high speed appeals to the
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