#23 March 1989
Section 22.214.171.124.023of the Artemis Data Book
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]
Contents of this issue of Moon Miners' Manifesto