Apollo 12 LM Flown & Signed SNAP 27 Pin

This incredible pin was flown to the lunar surface aboard Apollo 12 by Astronaut and Mission Commander Pete Conrad in November 1969.
Archive Id AP12-LNR-19


Apollo 12 Lunar Module Flown SNAP 27 RTG Tie Tacks originally from the Personal Collection of Pete Conrad. These pins depict Systems Nuclear Auxiliary Power Radioisotope Thermoelectric Generators with the moon in the background, approximately 0.5" x 0.625" in overall size. The pin is mounted on a 4.5" x 3" x 1" wooden desk plaque with an engraved plate stating: "Carried Aboard/ Apollo 12/ to the/ Ocean of Storms/ November 1969" and with a facsimile signature of Conrad beneath. These plutonium-238 powered devices were carried to the moon on the final five lunar modules to power the Apollo Lunar Surface Experiment Packages. Even years later, data was still being transmitted back to earth, powered by the SNAP 27s.

These SNAP 27 Pins were reunited with the remaining crew members of Apollo 12 and hand signed by both, and thus in a sense making them complete. A fitting tribute to their friend and crewman, Charles Conrad.


The Story of the SNAP 27 Pins

A total of 27 SNAP 27 Pins were flown to the Moon by Pete Conrad on behalf of Charles B. Appleman of General Electric. General Electric were the prime contractors for the SNAP 27 RTG. The pins themselves flew in PPK #1029 aboard the CSM, and upon arrival at the Moon did Conrad transfer them to the LM where they eventually landed at the Ocean of Storms.

About the SNAP Program

The Systems Nuclear Auxiliary Power (SNAP) program was a program of experimental radioisotope thermoelectric generators (RTGs) and space nuclear reactors flown during the 1960s by NASA.

Five SNAP-27 units provided electric power for the Apollo Lunar Surface Experiment Packages (ALSEP) left on the Moon by Apollo 12, 14, 15, 16, and 17. The fuel capsule, containing 3.8 kilograms (8.4 lb) of plutonium-238 in oxide form (44,500 Ci or 1.65 PBq), was carried to the Moon in a separate fuel cask attached to the side of the Lunar Module. The fuel cask provided thermal insulation and added structural support to the fuel capsule. On the Moon, the Lunar Module pilot removed the fuel capsule from the cask and inserted it in the RTG.

These stations transmitted information about moonquakes and meteor impacts, lunar magnetic and gravitational fields, the Moon's internal temperature, and the Moon's atmosphere for several years after the missions. After ten years, a SNAP-27 still produced more than 90% of its initial output of 70 watts.

The fuel cask from the SNAP-27 unit carried by the Apollo 13 mission currently lies in 20,000 feet (6,100 m) of water at the bottom of the Tonga Trench in the Pacific Ocean. This mission failed to land on the moon, and the lunar module carrying its generator burnt up during re-entry into the Earth's atmosphere, with the trajectory arranged so that the cask would land in the trench. The cask survived re-entry, as it was designed to do, and no release of plutonium has been detected. The corrosion resistant materials of the capsule are expected to contain it for 10 half-lives (870 years).