In 1974, the late Princeton University professor and space visionary Gerard O’Neill proposed using electromagnetic rail guns to capture payloads from the moon.
O’Neill proposed using “mass drivers”, based on a coil gun design, to accelerate a non-magnetic object. One application for mass drivers was launching lunar-derived materials into lunar orbit for production in space. O’Neill also worked on mass drivers at MIT, working with colleague Henry H. Kolm and a group of far-sighted student volunteers to fabricate their first mass driver prototype. Supported by grants from the Space Studies Institute, later prototypes improved on the mass driver concept.
That was five decades ago. Catapult yourself to today and ask this question: What does the US Navy’s nuclear aircraft carrier Gerald R. Ford have to do with the moon?
Future lunar economy
Late last year, General Atomics Electromagnetic Systems submitted a final report to the Air Force Office of Scientific Research (AFOSR). That report was titled “Lunar Electromagnetic Launch for Resource Exploitation to Enhance National Security and Economic Growth.”
The author of that assessment is Robert Peterkin, director of operations for the organization’s Albuquerque, New Mexico, office.
The 30-page document highlights that the moon is rich in useful resources, including silicon, titanium, aluminum and iron. The prospect of tapping into lunar water also looms large.
“A not-too-distant future lunar economy will leverage these lunar resources to supply, repair, and refuel spacecraft in lunar orbit at a lower cost than providing terrestrial resources from Earth’s deep gravity well,” explains the report.
Machines, constructions, systems
Electromagnetic launches of material from the lunar surface, the report continues, could be significantly more efficient than conventional rocket launches that rely on chemical fuels imported from Earth to the moon.
The assessment makes recommendations on how to develop the technology needed to launch extracted and processed lunar material into cislunar space to support a range of emerging space missions.
A particularly important aspect of developing a lunar economy, the report recommends, is moving mass from the moon’s surface reliably, affordably and safely. “Undoubtedly, the first spiral of a lunar ecosystem development cycle will depend on the supply of machinery, structures, and support systems from Earth.”
Superior choice
Using lunar resources to repair and supply cis-lunar spacecraft will require advances in several technologies, including a reliable way to move material from the lunar surface, Peterkin told Space.com.
For that task, a modern electromagnetic launch vehicle is a superior choice, Peterkin said, because it can use abundant solar energy as its main energy source instead of importing chemical rocket fuel from Earth.
“The U.S. government should fund an evolution of the existing electromagnetic aircraft launch system, which now operates reliably on the U.S. Navy’s Gerald R. Ford nuclear aircraft carrier,” Peterkin points out.
This carrier-based hardware, manufactured by General Atomics, is called the Electromagnetic Aircraft Launch System (EMALS).
Path to get there
Peterkin said advancing this Earth-based technology will involve achieving higher speed, at lower mass – and shows work that accelerates a lunar launch capability in fast forward mode.
The lickety-split speed needed to hurl pound-class payloads from lunar terrain into a low circular orbit around the moon is 3,758 miles per hour (1.68 kilometers per second).
“To prove viability, we must demonstrate that this approach can achieve lunar orbit speed,” Peterkin said, “for at least 100 launches without the need to replace launcher components.”
As the report to the Air Force Office of Scientific Research states, “while it is important to envision a mature state in which a self-sustaining lunar ecosystem extracts, processes, and launches lunar material into lunar space to support cislunar spacecraft build, deliver, and sustain space settlements, it’s just as important to chart a path to get there.”