Organics in Apollo Lunar Samples

Introduction: One of many unknowns prior to the Apollo landings concerned the possibility of life, its remains, or its organic precursors on the surface of the Moon. While the existence of lunar organisms was considered highly unlikely, a program of biological quarantine and testing for the astronauts, the Apollo Command Modules, and the lunar rock and soil samples , was instituted in the Lunar Receiving Laboratory (LRL) [1]. No conclusive evidence of lunar organisms , was detected [2-4] and the quarantine program was ended after Apollo 14. Analyses for organic compounds were also conducted. Considerable effort was expended, during lunar surface operations and in the LRL, to minimize and quantify organic contamination [5]. Post-Apollo curatorial operations and cleaning minimize contamination from particulates, oxygen, and water but no longer specifically address organic contamination. The organic compounds measured in Apollo samples are generally consistent with known sources of contamination. Lunar Sample Collection and Contamination Control: The lunar rock and soil samples were collected using simple geologic tools including hammers, shovels, rakes, and core tubes. Most samples were placed into pre-cleaned, numbered bags. Some samples , collected for specific high-sensitivity tests, were placed in dedicated metal containers. Upon returning to the Lunar Module the astronauts put most sample bags, containers, core tubes, and loose samples into pre-cleaned aluminum cases. The cases were sealed in the lunar vacuum, and the samples were kept in these sealed cases thru Earth return. The cases were opened under controlled conditions in the LRL [6]. Apollo planners conducted extensive organic contamination monitoring of the containers, tools, and sample handling facilities. Simoneit and Flory [7] summarized the potential sources of organic contamination: 1) surface contamination of the lunar-bound rock box and its contents; 2) surface contamination on the Apollo lunar hand tools used to obtain samples on the lunar surface; 3) exhaust products from the lunar descent engine and reaction control system engines (both using unsymmetrical dimethyl hydrazine and nitrogen tetraoxide); 4) lunar module outgassing; 5) astronaut spacesuit leakage; 6) particulate material abraded from spacesuit or other sources during EVA; 7) venting of lunar module fuel and oxidizer tanks, cabin and waste systems; 8) venting of spacesuit life