Apollo 16 Gamma Ray Spectrometer Encasement

The bombardment of the lunar surface by galactic cosmic rays causes some elements to emit gamma rays. The Gamma Ray Spectrometer measured this radiation from lunar orbit to produce maps of the abundances of thorium, iron, and titanium on the lunar surface. The different elements were identified based on the energy of the gamma-rays that they emitted, with 100km resolution. This experiment found high iron abundances over all mare regions and lower abundances elsewhere. Thorium and titanium abundances were also highest over mare regions, but these two elements varied considerably in abundance in different parts of the maria.

The G.R.S. (Gamma Ray Spectrometer) Cover Parts Control Tag (below) says it was “removed from G.R.S. in S/C 113” on 2/29/72. This would have been spacecraft 113, the Apollo 16 CSM, and it looks like the cover was removed 1.5 months before launch, as indicated. The tag also reads “GRS SN-004” and “CSM-A103566” and “RETURN TO “J” MISSION BOND RM” NASA describes the bond room as “a bonded area to receive components as they were removed from the CM. This area was provided with a receiving table; 10 storage cabinets for small components; and areas for large components”

The tag is on the plastic case, adorned with yellow text to REMOVE BEFORE LAUNCH; not sure about the metal cylinder inside with the cables. The custom plug at the deployment end of the boom mates perfectly with the boom box (the silver cylinder in the yellow case)

The top yellow text reads “Boom Mating End.” There is also a taped message: “REMOVED FROM AERS-SN-004 PER K3550 11/2/71” (in between Apollo 15 and 16).