Returning to the moon for rocket fuel and clean energy

Returning to the moon for rocket fuel and clean energy
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Before the first Apollo missions, the moon was thought to be a bone-dry, rocky world of interest to geologists and few others. However, the Apollo lunar samples, as well as decades of remote sensing missions, suggest that Earth’s nearest neighbor has abundant natural resources. These resources will not only facilitate the building of lunar settlements but might fuel a space-based industrial revolution. 

NASA’s JPL divides lunar resources into water, helium-3 and rare earth materials. In addition, the Apollo samples suggest that the moon has some quantity of industrial minerals such as iron, titanium, silicon and aluminum. The Clementine mission that took place in the early 1990s confirmed the presence of industrial metals in lunar soil. Scientists also postulate the presence of platinum group metals in areas of the moon that endured asteroid impacts. Oxygen is chemically bonded in lunar soil.

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Of all the minerals that have been detected on the moon or thought to be on the moon, helium-3 is the only one that might be economical to return to Earth. The isotope, deposited on the lunar surface for billions of years by solar wind, is thought to be the perfect, nonpolluting fuel for future fusion reactors. Unfortunately, the technology to build such reactors does not yet exist. However, helium-3-fueled fusion would unlock a limitless, pollution-free power source that does not emit greenhouse gasses.

Water, confirmed to exist in deposits of ice in permanently darkened craters at the poles of the moon, can be used for drinking and agriculture and cracked into rocket fuel, making the moon a perfect pit stop for spacecraft headed into deep space. Water mined from the moon does not have to be imported from Earth.  Oxygen to breathe can be extracted from the water or from lunar soil. 

The rest, including industrial and platinum group metals and rare earths, can be mined from the moon to not only sustain lunar settlers, but to start a space-based industrial revolution. The late Paul Spudis postulated it would not make economic sense to export lunar materials in even their refined form all the way to Earth. However, such minerals could be used to facilitate lunar settlements and fuel space-based industries. 

Lunar minerals could be mined and refined by robots. The materials could be launched from the moon to space-based factories using rail guns, a technology, as Space.com pointed out, that is currently being developed as a weapon of war.

Space-based factories would create new products using microgravity, hard vacuum, and the extremes of heat and cold that could not be readily developed on Earth. Lunar materials could be used to build large structures, such as communication arrays, space telescopes and solar power satellites, that could not be launched from Earth in one piece.

A company called Made in Space has been testing a 3D printer on the International Space Station for the past several years. One product the company is contemplating for building in space for export to Earth is an advanced fiber-optic cable that could revolutionize communications, medical imaging, and supercomputers, among other applications. The advanced fiber optic cable is just one of many products, including lightweight, super-strong alloys being contemplated for manufacture in space for export to Earth. 

Along with Northrup Grumman and Oceaneering, Made in Space is developing a space manufacturing robot called Archinaut. Archinaut would integrate a 3D printer and robot manipulator arms to build large-scale structures in space. It could also be used to grab and either repair or recycle dead satellites, thus eliminating a source of space junk.

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Research and development of space-based manufacturing is still in its infancy. Also, the economics of a space industrial sector needs to develop costs that are low enough to make sense. Access to lunar materials will help to drive down that cost since launching them with a moon-based rail gun will be less expensive than launching them from Earth.

Creating a space-based industrial revolution using lunar materials will be the work of many years with an enormous investment by both government and industry needed. However, the wealth creation that could result very likely would more than pay the cost of returning to the moon and creating a mining, refining and transportation infrastructure. The economic benefits of returning to the moon constitute a powerful case for undertaking the program and not allowing politics to derail it for a third time in a generation.

Mark Whittington is the author of space exploration studies “Why is It So Hard to Go Back to the Moon? as well as “The Moon, Mars and Beyond.”