APS Engine

I was excited to see this Lunar Module Ascent Propulsion System engine again. I had seen it at Glenn Research Center on my last visit before it shut down its on-site visitor center, and was disappointed that the engine hadn't made its way to the Great Lakes Science Center when the museum became GRC's visitor center.

When I visited the engine at GRC, its exit plane was very close to the wall, preventing photography of the engine's injector. The GRC Community Relations rep moved it for me, but then moved it back, so I only got a few photos of the engine's injector.

Unfortunately, the engine's exit plane was once again up against the wall in this gallery. I emailed the museum, asking if I could arrange for it to be moved. They begged off, suggesting that I come back when NASA took down the exhibit. I emailed John Oldham, the GRC exhibits specialist, to verify that it would be OK to photograph the engine while he was working. Not only did he move the engine as I wanted, but when he saw me trying to photograph the bottom of the valve package assembly, he also rotated it on its stand so that I could more easily photograph it. So, the photographs here are of the engine as it was moved around in the gallery.

APS engines are fairly rare: I've only seen them at the Cernan Earth & Space Center, the USSRC, and the Smithsonian (although the latter looks unlike the others I've seen); installed in LM-2; and a bare APS thrust chamber at the Michigan Space & Science Center (now at the Air Zoo).

These engines are all displayed on their exit plane (or in a Lunar Module), so this is the only engine of which I am aware which allows inspection of the interior of the thrust chamber and its injector.