By 
April 8th, 2017
Electromagnetic mass drivers using solar power provide low cost transportation of materials to space construction sites.
Courtesy: Space Studies Institute
Recent testing of an electromagnetic railgun by the U.S. Navy has led to firing a projectile up to Mach 6 – approaching a velocity that harkens back to early ideas of utilizing this technology 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 Moon is about 5,300 mph.
Credit: Office of Naval Research
Magnetic fields
The Office of Naval Research work on the EM Railgun launcher is being pursued as a long-range weapon that fires projectiles using electricity instead of chemical propellants.
Magnetic fields created by high electrical currents accelerate a sliding metal conductor, or armature, between two rails to launch projectiles.
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
Moon-launched payloads
In 1974, Princeton 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 are based on the 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.
Mass driver work
O’Neill worked at MIT on mass drivers, working with 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.
Sparks of creativity. Mass driver workers Gerard O’Neill (center), Henry Kolm (left), Kevin Fine (right).
Electromagnetic thrust
In regards O’Neill’s seminal mass driver work, according to an official at the Office of Naval Research, contacted by Inside Outer Space: “Very interesting proposal to use electromagnetic launchers for space vehicles. Considering the fact that the railgun is working with a small hyper-velocity projectile, and requires significant power and thermal management, I suspect working out the details for movement of larger space vehicles/payloads is a long way off,” the official said. “But I also believe that current efforts will be successful and electromagnetic thrust will eventually be considered for other applications, including space.”
Resources
Check out this video published on March 26, 2017 showing work on the U.S. Navy’s EM Railgun at:
https://www.youtube.com/watch?v=5imlcR0CuJ0
Professor Gerard K. O’Neill founded the Space Studies Institute (SSI) in 1977 with the hope of opening the vast wealth of space to humanity.
For more information on SSI’s on-going work, go to:
Posted in Space News
