NASA's Lunar Lander project office has studied a Soviet lunar lander design that has a two-stage powered descent system.
The Soviet space programme's single crew lunar lander employed a stage that it detached during the descent. The remainder of the descent was powered using what would become the vehicle's ascent engine.
The Soviet design analysis came to light during NASA's 20 July public panel discussion with retired engineers that were former members of the Grumman corporation's Lunar Module reliability and maintainability team. Grumman was the Apollo programme's Lunar Module contractor.
"The [NASA] LSAM team have looked at the drop stage, but that has a need for a wet ascent stage," says ex-Grumman Apollo lunar module engineer Joseph Frogola, speaking at the meeting. The reference to a "wet" ascent stage means that it had been fired already.
The LSAM or Lunar Surface Access Module was the name given to the lunar landing craft under NASA's 2005 exploration systems architecture study report.
Recommendations the engineers had for NASA's Lunar Lander project office included the need for a "seamless" NASA/contractor integration team, to take a "total systems" view that includes the Ares V cargo launch vehicle booster and Orion crew exploration vehicle, and to have a reference mission very early on in the design process.
During the meeting former Grumman engineers expressed the hope that Apollo Lunar Module systems could one day be brought back from the Moon to study the effects that its environment had had on them, including the dust's effect on electronics. Stress corrosion was another issue of interest for the engineers.