DPS Engine Mockup

For a short time, two lunar module engine mockups, a Descent Propulsion System (DPS) engine mockup and an Ascent Propulsion System (APS) engine mockup, were located in the lobby of the "old" museum building (where the ticketing counters and gift shops were once located). Both are constructed of what appears to be sheet metal and seem hollow (perhaps double-walled?).

These engines were displayed for only a short time, and the APS mockup was later part of the "NASA - A Human Adventure" (scroll down to the fourth photo), so I speculate that the DPS mockup was also part of this exhibit.

Based on an ID plate on the engine, it appears that this is actually a mockup of Rocketdyne's entry in Grumman's competition for the DPS engine. The Rocketdyne ID plate implies that this is an "SE-10" engine (recall that Rocketdyne manufactured the SE-7 and SE-8 thrusters were used on the Gemini spacecraft and the SE-7-1 thruster used in the S-IVB's Auxiliary Propulsion System). A Google search for "SE-10" had few results, but "Liquid-Propellant Rocket Engine Throttling: A Comprehensive Review" [direct link to 2.5 meg PDF] does refer to the SE-10 as Rocketdyne's "LMDE concept" and as a "competing Apollo lunar descent engine". There are certainly a number of differences between this mockup and the final flight engine in its valves and plumbing, gimbal ring, and overall shape.

Of course, TRW's Space Technology Laboratories (STL) eventually won the contract and built the engines actually used by the Lunar Modules.

For additional information about the engine competition and development, see chapter 6 of Chariots for Apollo: A History of Manned Lunar Spacecraft.