ABSORBING THE SHOCK OF EAGLE'S LANDING.
Crushable aluminum honeycomb cartridge designed for the Lunar Module's landing gear primary struts, 48 inches tall, 5½ inches in diameter, and less than 5lb in weight. Finely-engineered aluminum in honeycomb formation, alloy caps and collar. Three Grumman paper parts labels, a few inspection stamps on the alloy parts. A few minor dents.
How to land Eagle safely on the moon? This was the problem faced by NASA and Grumman engineers. Once the "contact light" lit, indicating the Lunar Module's probes had touched the lunar surface, Armstrong and Aldrin would shut off the engines and the LM would drop the remaining distance to the ground. Conventional hydraulic or pneumatic shock absorbers in the landing gear would be heavy and could leak, and Tom Kelly of Grumman insisted on a reliable and lightweight design. A company called Hexcel had developed aluminum honeycomb as a lightweight, rigid, high-strength filler material for aircraft control surfaces; they suggested their honeycomb might fit the bill. The landing gear would suffer only a one-time shock, so a reusable system was unnecessary. The honeycomb would be the buffer for an inner cylinder as it slid up inside an outer cylinder.
Compressing by as much as 32 inches, the honeycomb was designed for an impact of up to ten feet per second. In fact no Apollo mission landed at more than four feet per second. As a result, Eagle's struts did not collapse as much as expected, leaving the ladder some way above the moon's surface. Just after exiting the LM, Armstrong remarked "I just checked getting back up to that first step, Buzz. It's ... the strut isn't collapsed too far, but it's adequate to get back up."
Designed for the sole purpose of landing a man on the moon, this object is a fine example of the ingenuity that made the Apollo landings a success.