Development of an evolved gas-time-of-flight mass spectrometer for the Volatile Analysis by Pyrolysis of Regolith (VAPoR) instrument

Low power, robust technologies are appealing for in situ planetary science throughout the Solar System. The VAPoR (Volatile Analysis by Pyrolysis of Regolith) instrument is under development toward studying soil composition, volatiles, and trapped noble gases in the polar regions of the Moon and on the surface of other airless bodies. VAPoR will ingest a soil sample and conduct analysis by pyrolysis and time-of-flight mass spectrometry (ToF-MS). Two components of the system have been characterized in parallel development: a field-tested sample heater design and a laboratory-based time-of-flight mass spectrometer that emphasizes reduced mass and power through the use of micro- and nanotechnology. The pyrolysis field unit, vacuum-coupled to a commercial residual gas analyzer, has been used in Hawaii to analyze Mauna Kea soils. Water was detected, as were key inorganic pyrolysis products, including CO(2) and SO(2), and organic volatiles, including methane, benzene, toluene, and various hydrocarbon fragments. In parallel development, a laboratory reflectron time-of-flight mass spectrometer has been designed, assembled, and tested using electron impact ionization from a carbon nanotube electron gun. Preliminary testing reveals a mass resolution of 270. Published by Elsevier B.V.