Apollo 16 Lunar Module Foil
A 8x8” book of Kapton foil, Velcro, tape and some unusual rectangular orange patches (detail of that below). Apollo 16 with LM Orion launched 40 years ago, on April 16.
You probably remember the lunar modules, wrapped in bright gold like a present to the cosmos. I always thought that there was one layer of foil to reflect the harsh sunlight in space.
I was surprised to see that this blanket from the Apollo 16 LM was made of 26 layers, of different colors and thicknesses.
As I recently learned, the foil was also a thermal blanket, not just a reflector. Earlier this month, EDN Magazine interviewed Grumman’s Ross Bracco, one of 25 engineers who began development of the LEM, as it was first called:
“Still another major challenge Bracco and his team faced was the fact that the LEM was expected to land on the sunny side of the lunar surface, which meant an environmental temperature of 250°F and a shade temperature of -250°F. A low-cost technique was needed to insulate and protect the LEM's structural materials, including the landing feet. The team decided to use 12 to 18 layers of Kapton or aluminized Mylar material sandwiched together in a 70°F earth clean room and trap the air with a special sealing tape. This trapped air remained permanently at 70°F and was used in many areas of the LEM, including the cupped landing feet. The ‘foil’ around much of the LEM was made with 2- and 5-mil aluminized Kapton film.”