Artist’s concept of rail gun aboard ship. Credit: U.S. Navy



It’s going fast…and there’s a new directed energy arms race.

One project that’s part of that scenario is the Navy’s electromagnetic (EM) “rail gun,” reportedly due soon to see testing on a warship. That technology may have off-world implications for future Moon exploration and exploitation.

The Office of Naval Research work on the EM rail gun launcher is being pursued as a long-range weapon that fires projectiles using electricity instead of chemical propellants.

Electromagnetic mass drivers using solar power provide low cost transportation of materials to space construction sites.
Courtesy: Space Studies Institute

Recent testing of the electromagnetic rail gun under Navy auspices had the technology firing a projectile that exceeds Mach 6 – approaching a velocity that harkens back to early ideas of utilizing this machinery on the Moon to hurl payloads from the lunar surface.

Mach 6 equals 4,567.24 miles per hour with the escape velocity from the nearly airless Moon being about 5,300 mph.

Sparks of creativity. Mass driver workers Gerard O’Neill (center), Henry Kolm (left), Kevin Fine (right).

Payloads from the Moon

In 1974, Princeton University professor and space visionary, the late Gerard O’Neill first proposed use of an electromagnetic rail gun to lob payloads from the Moon.

“Mass drivers” based on a coilgun design were adapted to accelerate a non-magnetic object. One application O’Neill proposed for mass drivers: toss baseball-sized chunks of ore mined from the surface of the Moon into space. Once in space, the ore could be used as raw material for building space colonies and solar power satellites.

Given today’s push for plumbing and processing ice-rich craters on the Moon, could that water-ice resource shot off the Moon also be part of a cis-lunar, fuel-making enterprise?

Deflection plates near the end of the mass driver make minute adjustments to the trajectory of the launched ore to ensure it reaches its target: a mass catcher at the L-2 point.
Courtesy: Space Studies Institute

Mass driver work

O’Neill worked at MIT on mass drivers, along with colleague Henry H. Kolm, and a group of student volunteers to construct their first mass driver prototype.

Backed by grants from the Space Studies Institute, later prototypes improved on the mass driver concept, showing that a mass driver only 520 feet (160 meters) long could launch material off the surface of the Moon.

Ocean of space

Meanwhile, according to a story last Friday from the Seattle Times, the Navy’s latest Northwest Training and Testing draft Supplemental Environmental Impact Assessment explains that “the kinetic energy weapon (commonly referred to as the rail gun) will be tested aboard surface vessels, firing explosive and non-explosive projectiles at air- or sea-based targets.”

According to the assessment, “the system charges for two minutes and fires in less than one second,” also noting that “the system is shielded so as not to affect shipboard controls and systems. The amount of electromagnetic energy released from this system is low and contained on the surface vessel.”

As this know-how is trial-run on the Earth’s ocean…could it be a forerunner of technology useful for the ocean of space – a Moon-based technology?

Go to this video to see the Navy’s rail gun in operation:

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