NASA Considering Rail Gun Launch System to the Stars

by Nancy Atkinson on September 14, 2010

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This artist's concept shows a potential design for a rail-launched aircraft and spacecraft that could revolutionize the launch business. Credit: NASA/Artist concept

The idea for using rail guns to launch objects to space has been around for years – even Isaac Newton considered the concept. But now a group of NASA engineers is seriously studying the possibility of using a rail gun as a potential launch system to the stars, and they are looking for a system that turns a host of existing cutting-edge technologies into the next giant leap spaceward. Stan Starr, branch chief of the Applied Physics Laboratory at Kennedy Space Center said that nothing in the design calls for brand-new technology to be developed, but counts on a number of existing technologies to be pushed forward. He said developing such a system would be a “major technology revolution.”

“All of these are technology components that have already been developed or studied,” he said. “We’re just proposing to mature these technologies to a useful level, well past the level they’ve already been taken.”

A rail gun utilizes a magnetic field powered by electricity to accelerate a projectile along a set of rails, similar to train rails. One early proposal from the NASA group calls for a wedge-shaped aircraft with scramjets to be launched horizontally on an electrified track or gas-powered sled. The aircraft would fly up to Mach 10, using the scramjets and wings to lift it to the upper reaches of the atmosphere where a small payload canister or capsule similar to a rocket’s second stage would fire off the back of the aircraft and into orbit. The aircraft would come back and land on a runway by the launch site.

The engineers, from KSC and other NASA centers, contend the system, with its advanced technologies, will benefit the nation’s high-tech industry by perfecting technologies that would make more efficient commuter rail systems, better batteries for cars and trucks, and numerous other spinoffs.

Different technologies to push a spacecraft down a long rail have been tested in several settings, including this Magnetic Levitation (MagLev) System evaluated at NASA's Marshall Space Flight Center. Engineers have a number of options to choose from as their designs progress. Photo credit: NASA

For example, electric tracks catapult rollercoaster riders daily at theme parks. But those tracks call for speeds of a relatively modest 100 km/h (60 mph) — enough to make the ride exciting, but not nearly fast enough to launch something into space. The launcher would need to reach at least 10 times that speed over the course of two miles in Starr’s proposal.

The good news is that NASA and universities already have done significant research in the field, including small-scale tracks at NASA’s Marshall Space Flight Center in Huntsville, Ala., and at Kennedy. The Navy also has designed a similar catapult system for its aircraft carriers.

As far as the aircraft that would launch on the rail, there already are real-world tests for designers to draw on. The X-43A, or Hyper-X program, and X-51 have shown that scramjets will work and can achieve remarkable speeds.

The group sees NASA’s field centers taking on their traditional roles to develop the Advanced Space Launch System. For instance, Langley Research Center in Virginia, Glenn Research Center in Ohio and Ames Research Center in California would work on different elements of the hypersonic aircraft. Dryden Research Center in California, Goddard Space Flight Center in Maryland and Marshall would join Kennedy in developing the launch rail network. Kennedy also would build a launch test bed, potentially in a two-mile long area parallel to the crawlerway leading to Launch Pad 39A.

Because the system calls for a large role in aeronautic advancement along with rocketry, Starr said, “essentially you bring together parts of NASA that aren’t usually brought together. I still see Kennedy’s core role as a launch and landing facility.”

The Advanced Space Launch System is not meant to replace the space shuttle or other program in the near future, but could be adapted to carry astronauts after unmanned missions rack up successes, Starr said.

The studies and development program could also be used as a basis for a commercial launch program if a company decides to take advantage of the basic research NASA performs along the way. Starr said NASA’s fundamental research has long spurred aerospace industry advancement, a trend that the advanced space launch system could continue.

For now, the team proposed a 10-year plan that would start with launching a drone like those the Air Force uses. More advanced models would follow until they are ready to build one that can launch a small satellite into orbit.

A rail launcher study using gas propulsion already is under way, but the team is applying for funding under several areas, including NASA’s push for technology innovation, but the engineers know it may not come to pass. The effort is worth it, however, since there is a chance at revolutionizing launches.

Source: NASA

About 

Nancy Atkinson is Universe Today's Senior Editor. She also works with Astronomy Cast, and is a NASA/JPL Solar System Ambassador.

Dark Gnat September 15, 2010 at 4:41 AM

If it were built at higher altitudes, it might work. Less dense air would not have as much of a shock, and there would be less drag.

It wouldn’t work in orbit. Contrary to popular belief (brought on by video games and movies), rail guns do have recoil. In space, the rialgun and projectile would be propelled in opposite directions, so a lot of energy would be wasted, and you would then have to retrieve the launcher.

I think it would be great on the Moon though, but that would only be cost effective after a successful colony has been established.

I still think rockets are the way. They are loud, dirty, and expensive, but they work. I can also see a piggy-back system working too (space plane rides on top of a large 747 style jet).

Astrofiend September 15, 2010 at 4:42 AM

“There really is not much point in using jxB to sent a craft screaming out of a rail launcher at Mach 4 or something, only to have over half that energy dissipated away in a huge thermal shock wave that rattles windows all the way to Miami.

LC”

Yeah – but it would be cool though…

Astrofiend September 15, 2010 at 4:44 AM

“I still think rockets are the way. They are loud, dirty, and expensive…”

You sold me at loud and dirty…

stan9fos September 15, 2010 at 6:28 AM

Needs to be built in the Rockies or other high altitude location. As a former resident of “Florida’s Space Coast”, I can testify to the fact that the atmosphere is too dense & humid for humans, much less hypersonic aircraft. Hasn’t anybody at NASA seen “When Worlds Collide?”

Maxwell September 15, 2010 at 7:52 AM

I think the old statistic was something like: 90% of the fuel is spent in the first two minutes. So in theory, if you can get the payload up to a certain speed and altitude before you start the burn, you can make a very efficient machine.

Its the same theory behind air-launching. Only you’re avoiding the cost and limitations of building a flying mothership.
…although I think a giant carrier aircraft would be cheaper in the short term.

Lawrence B. Crowell September 15, 2010 at 8:41 AM

The point of rockets is that they get above 90% of the Earth’s atmosphere within a minute. Further, they are arrow shaped which minimizes the surfaces which can form shock wave fronts. The artist rendition is a bit silly on that last front, for the leading edge of this craft is broad, which will generate lots of shock wave energy. Further, by heading out on a semi-horizontal path, instead of an initially vertical path, you are passing through more atmosphere.

LC

Uncle Fred September 15, 2010 at 4:30 PM

So there is no way this can be done in a manner that makes it more cost effective then rockets?

Torbjorn Larsson OM September 16, 2010 at 8:03 AM

Iantresman, your history is entirely off rails! Linear motors hark back to 1918. The first railgun was built 1950.

I assume you mention coil guns instead because it was Birkeland/shades of EU. If so, please take your pseudoscience religion elsewhere.

Torbjorn Larsson OM September 16, 2010 at 8:11 AM

The artist rendition is a bit silly on that last front, for the leading edge of this craft is broad, which will generate lots of shock wave energy.

I believe that nose design is an archetype from the linear rocket booster ideas. A waverider engine would benefit from a broad front too, and current scramjet design use it. Note the shock wave simulation (well, as good as the implied CFD simulation can do it, I guess) in the link. The engine and trailing edge is what generates them!

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