Engineering topics

Swindle, T.

Publications and source records attributed to Swindle, T..

4 records

NASA NTRS2008

Volatile Analysis by Pyrolysis of Regolith (Vapor) on the Moon using Mass Spectrometry

The identification of lunar resources such as water is a fundamental component of the the NASA Vision for Space Exploration. The Lunar Prospector mission detected high concentrations of hydrogen at the lunar poles that may indicate the presence of water or other volatiles in the lunar regolith [1]. One explanation for the presence of enhanced hydrogen in permanently shadowed crater regions is long term trapping of water-ice delivered by comets, asteroids, and other meteoritic material that have bombarded the Moon over the last 4 billion years [2]. It is also possible that the hydrogen signal at the lunar poles is due to hydrogen implanted by the solar wind which is delayed from diffusing out of the regolith by the cold temperatures [3]. Previous measurements of the lunar atmosphere by the LACE experiment on Apollo 17, suggested the presence of cold trapped vola'tiles that were expelled by solar heating [4]. In situ composition and isotopic analyses of the lunar regolith will be required to establish the abundance, origin, and distribution of water-ice and other volatiles at the lunar poles. Volatile Analysis by Pyrolysis of Regolith (VAPoR) on the Moon using mass spectrometry is one technique that should be considered. The VAPoR pyrolysis-mass spectrometer (pyr-MS) instrument concept study was selected for funding in 2007 by the NASA Lunar Sortie Science Opportunities (LSSO) Program. VAPoR is a miniature version of the Sample Analysis at Mars (SAM) instrument suite currently being developed at NASA Goddard for the 2009 Mars Science Laboratory mission (Fig. 1).

Glavin, D. P.↗

NASA NTRS1992

A Lunar Penetrator to Determine Solar-wind-implanted Resources at Depth in the Lunar Regolith

Several volatiles implanted into the lunar regolith by the solar wind are potentially important lunar resources. He-3 might be mined as a fuel for lunar nuclear fusion reactors. Even if the mining of He-3 turns out not to be feasible, several other elements commonly implanted by the solar wind (H,C, and N) could be important for life support and for propellant or fuel production for lunar bases. A simple penetrator-borne instrument package to measure the abundance of H at depth is proposed. Since solar-wind-implanted volatiles tend to correlate with one another, this can be used to estimate global inventories and to design extraction strategies for all of these species.

Boynton, W.↗

NASA NTRS1991

He-3 and other lunar volatiles

Constraints are considered and estimates are given for the abundances of He-3, other noble gases, and chemically reactive volatiles (e.g., H, C, N, S, F, Cl) on the Moon. For the case of surface inventories, solar wind particles implanted into grains on the surface of the Moon provide an accessible, though not necessarily abundant, source of H, C, N and the noble gases. Solar wind implanted species are concentrated in the infest grain sized, and are only found in the upper few meters of the regolith, where there are grains that have been directly exposed to the Sun. Elemental abundances in surface soils are typically 10s of mg/g, and vary according to the exposure history of the soil. The abundance of the rare, but possibly economically important, isotope He-3 is typically a few mg/g. The largest uncertainty in estimates of the total lunar abundance of solar wind implanted species comes from the lack of knowledge of their distribution with depth below the upper meter or two. For the case of bulk inventories, constraints resulting from lunar sample analyses and from physical chemical models of volatile behavior during the hypothesized giant impact origin of the Moon is used to give estimated abundances.

Fegley, B., Jr.↗

NASA NTRS1990

Helium-3 in the lunar regolith

A preliminary assessment of He-3 distribution in lunar soils was completed, including variations with soil location, depth, composition, grain size, and other parameters that might be useful in developing mining scenarios. One of the primary tools was a compilation of available analyses of He-3 in lunar samples. The compilation includes analyses of more than 250 numbered samples (plus duplicates and subsamples in many cases) from the American and Russian lunar programs, reported in nearly 100 publications. In addition, average abundances for soils from each of the Apollo landing sites were computed. These were coupled with models and measurements of other pertinent parameters.

Swindle, T.↗