In 1974, the late Princeton University professor and space visionary Gerard O’Neill proposed the use of electromagnetic railguns to launch cargo from the Moon.
O’Neill proposed the use of “mass actuators” based on a coil gun design to accelerate a non-magnetic object. One application for mass drivers has been to launch lunar-derived materials into lunar orbit for manufacturing in space. O’Neill also worked at MIT on mass controllers, along with colleague Henry H. Kohl and a group of forward-thinking student volunteers to produce their first prototype mass controller. Later prototypes, supported by grants from the Institute for Space Studies, improved the mass driver concept.
That was five decades ago. Catapult to the present day and ask yourself this question: What does the US Navy’s Gerald R. Ford nuclear aircraft carrier have to do with the moon?
The future lunar economy
Late last year, General Atomics Electromagnetic Systems submitted a final report to the Air Force Office of Scientific Research (AFOSR). The report was entitled “Lunar Electromagnetic Launch for Resource Exploitation to Enhance National Security and Economic Growth”.
This review was written by Robert Peterkin, Chief Operating Officer of the organization’s Albuquerque, New Mexico office.
The 30-page document emphasizes that the Moon is rich in useful resources, including silicon, titanium, aluminum and iron. Prospects for pumping into lunar water also loom large.
“The not-too-distant future lunar economy will use these lunar resources to replenish, repair, and refuel spacecraft in lunar orbit at a lower cost than delivering terrestrial resources from Earth’s deep gravity well,” the report explains.
Machines, structures, systems
Electromagnetic launches of material from the lunar surface, the report continues, can be significantly more efficient than conventional rocket launches that rely on chemical fuels brought from Earth to the moon.
The assessment outlines recommendations for maturing the technology necessary to launch extracted and processed lunar material into cislunar space to sustain a variety of emerging space missions.
A particularly important aspect of the development of the lunar economy, according to the report, is the reliable, cheap and safe transfer of matter from the surface of the moon. “The first spiral of the development cycle of the lunar ecosystem will undoubtedly depend on the supply of machinery, structures and support systems from Earth.”
An excellent choice
Using lunar resources to repair and resupply cis-lunar spacecraft requires advances in several technologies, including a reliable way to move material off the lunar surface, Peterkin told Space.com.
For this task, a modern electromagnetic launcher is an excellent choice, Peterkin said, because it can use abundant solar energy as its primary power source instead of importing chemical rocket fuel from Earth.
“The U.S. government should fund the development of the existing electromagnetic aircraft launch system that is now operating reliably on the U.S. Navy’s Gerald R. Ford nuclear-powered aircraft carrier,” Peterkin points out.
Made by General Atomics, this carrier-based hardware is called the Electromagnetic Aircraft Launch System (EMALS).
The way to get there
Peterkin said moving this Earth-based technology down the road involves achieving higher speeds at lower weights — demonstrating the work that will accelerate lunar launch capability into high-speed mode.
The smooth speed required to eject a Pound-class payload from the lunar terrain into low circular orbit around the Moon is 3,758 miles per hour (1.68 kilometers per second).
“To demonstrate viability, we need to demonstrate that this approach can reach lunar orbital speed,” Peterkin said, “for at least 100 launches without having to replace launch vehicle components.”
As the Air Force Office of Scientific Research report states, “while it is important to envision a mature state in which a self-sustaining lunar ecosystem acquires, processes, and launches material into lunar space to construct, supply, and maintain a cislunar spacecraft. and space settlements, it’s just as important to create a way to get there.”