NASA is to specify an expendable, liquid oxygen (LOX)- and liquid methane (LCH4)-powered ascent main propulsion engine for its Constellation programme's planned Lunar Lander. The lander will carry cargo and up to four astronauts to the Moon's surface from 2020.
A synopsis of its forthcoming request for proposals, published on 12 September by the US space agency's Glenn Research Center, described the Lunar Lander's main ascent engine as: "Pressure-fed with an inlet pressure of approximately 325lb/in2 [22.4bar] and...fixed vacuum thrust of 6,000lb [26.7N] and a vacuum specific impulse equal or greater than 355s. During nominal operations the engine will be capable of performing up to two engine starts with total burn duration of 450s. To meet the abort function, the design of the development engine(s) shall be capable of 90% thrust in approximately 500 milliseconds."
A baseline Lander design, referred to as the Lunar Surface Access Module (LSAM), which used LOX/LCH4 propulsion, was proposed under the 2005 NASA Exploration Systems Architecture Study report, on which Constellation is based. NASA's Lunar lander project office was to have completed at the end of July its Lunar Design Analysis Cycle (LDAC)-1 for the Constellation Lander. The synopsis suggests that LDAC-1 has proposed an LOX/LCH4 engine.
In 2006 NASA placed over $15 million worth of contracts with its Ares I crew launch vehicle first-stage prime contractor Alliant Techsystems and Alabama based-KT Engineering for LOX-methane engine development, which had possible uses for Constellation's Orion crew exploration vehicle's service module's main engine and the Lunar Lander.
For its new Lander specific engine development, Glenn Research Center has specified that the propulsion system "should be amiable to scaling +/-1,500lb/ft to account for the immaturity of the current lunar lander design".
Source: Flight International
