Moon Miners' Manifesto

#23 March 1989

Helium-3

MMM #23

March 1989

HELIUM 3

by Eric Ryden, Chicago Space Frontier L5

The January 1989 issue of Fusion Technology contains a report of the 1988 NASA Lunar Helium-3/Fusion Power Workshop. The meeting addressed the potential of mining helium-3 (³He) from lunar regolith for use on Earth in fusion energy, assuming practical ³He use around 2015. Researchers at the University of Wisconsin-Madison had proposed lunar ³He mining¹, based on previous analysis of lunar soil samples that showed that the Moon serves as a collector of helium deposited by solar winds. Natural ³He is scarce on Earth,

The workshop assessed fusion energy methods, and approaches for lunar surveying, mining, processing, storage, transportation, and facilities required for recovery.

Fusion involves the combination of light element atoms into heavier atoms to produce energy. [Ed. Fusion creation of atoms lighter than iron produces energy, of elements heavier than iron consumes energy] In comparing deuterium-tritium fusion, which uses two isotopes of hydrogen, with deuterium-³He fusion, the latter was considered to produce less radioactive wastes and higher electricity conversion efficiency, but would be more difficult to ignite and contain.

Analysis of lunar regolith showed that higher titanium dioxide (TiO₂) levels correspond to higher ³He levels, a relationship which could not be explained. Distribution of TiO₂ might be made by remote sensing to infer ³He distribution, since ³He cannot be directly detected. [Ed. Higher titanium concentrations are found principally in some mare basalts. We may also want to map high-titanium basalt distribution in the maria to locate the best concentrations of ilmenite, an iron-titanium ore whose processing would produce liquid oxygen.]

Most ³He is concentrated in regolith [fines] smaller than 50 micrometers, thus screening and sorting collected material for this portion is desired. Following processing, separated helium would require isotope distillation to obtain ³He from the more prevalent ⁴He. Isotope distillation could be performed on the Moon or after transport to Earth [Ed. involving a severe weight penalty for the included unsalable ⁴He].

Lunar oxygen production from ilmenite (FeTiO₃) after 2000 could demonstrate lunar mining and processing, as well as generating metals and small amounts of ³He as byproducts. However, this process is not efficient for ³He production because most helium would be lost in the concentration of FeTiO₃ from regolith. Alternatively, heating regolith for ³He production also creates volatiles such as water, which could be utilized for other lunar activities. Thus the existence of either a lunar base or a ³He production facility could affect the planning and development of the other.

Further details of the workshop are contained in NASA Conference Publication 10018.

1Wittenberg, L.J., Santarius, J.F., and Kulcinski, G.L, "Lunar Source of ³He for Commercial Fusion Power. Fusion Technology 10:167-178, 1968. [for a copy, send SASE to MLRS/Helium3, PO Box 2102, Milwaukee, WI 53201]

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