|Fig. 1: Illustration of a lunar mining facility. (Courtesy of NASA Source: Wikimedia Commons)|
Initially discovered in 1985 by a group of students at the University of Wisconsin, it was noticed that the moon's surface contained large amounts of He-3.  This is a lightweight isotope of the element Helium that has two protons and one neuron. Helium is the gas that fills birthday balloons. He-3 has also been found on the orbiting American satellites. It is believed that the He-3 on the moon comes from the solar winds that hit the moon's surface every day. As recently as 2017, plans have been made to extract the Helium-3 from the moon.
He-3 is found on planet Earth, but only in small quantities. He-3 has multiple uses ranging from homeland security and national defense to medicine, industry and science. 
Lunar mining is not necessarily a new topic in the space exploration era. In the samples that Neil Armstrong brought back with him after his landing on the moon showed that He-3 was present in approximately 13 parts per billion (ppb). However it is now estimated that most samples contain 20 to 30 ppb. To extract the isotope, the lunar soil is heated and agitated to release the gas. As the vapors cool to absolute zero, the various gases that were released sequentially separate out of the mix. Finally, a special membrane would separate the He-3 from the ordinary helium gas.  The projected value of one ounce of He-3 is $40,000.  A facility (Fig. 1) that could complete this mining project is projected, all costs included, to run as much as $15 billion. 
The largest problem that is currently facing the science community is who should be entitled to mine He-3 on the moon? The UN created a document in 1967 called the Outer Space Treaty, but it did not discuss the question on exploiting this element from the moon.  The 1979 Moon Agreement begins to lay the foundation for an eventual framework for exploring this mining effort, but, as of yet, few countries have ratified this agreement.
In July of 2017, private space flight company Moon Express revealed plans to build a robotic outpost on the southern pole of the Moon as early as 2020. The company will develop a new type of spacecraft to transport materials to and from Earth and the Moon. The company has regulatory approval from the US government, but as mentioned above, there is still the international question to be answered.
© Brandon Wulff. The author warrants that the work is the author's own and that Stanford University provided no input other than typesetting and referencing guidelines. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.
 H. H. Schmitt, "Mining the Moon," Popular Mechanics 181, No. 10, 57 (October 2004).
 D. A. Shea and D. Morgan, "The Helium-3 Shortage: Supply, Demand, and Options for Congress," Congressional Research Service, R41419, December 2010.
 R. Bilder, "A Legal Regime for the Mining of Helium-3 on the Moon: U.S. Policy Options," Fordham International Law Journal 33, 243 (2010).