NASA Considering Rail Gun Launch System to the Stars


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 β€œmajor 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

29 Replies to “NASA Considering Rail Gun Launch System to the Stars”

  1. It’s not vision NASA is lacking, it’s money. It’s easy to have vision when you have the federal government throwing money at you like it was in the 1950s and 1960s (as part of the Cold War effort). If NASA sank its billions into “bold” and “visionary” rail gun tech then there would be nothing left for everything else it has on it’s plate — bye bye planet hunting space telescopes, for example. Not only that, if their investment in rail gun tech turns out to have been backing the wrong horse, we could be left with nothing to show for all the billions and years of effort.

  2. You also have one-and-a-half wars sucking up hundreds of billions of dollars a year along with a very shaky economy that could so with some more stimulus spending but with no will in Washington to do it because of a bunch of whiny teabaggers who gripe about paying too many taxes despite paying fewer taxes than Americans have in at least 60 years (and probably a lot longer).

  3. Engineering-wise it looks like a winner. However getting the program approved for full development is a long process and may take many years. through the approval process at NASA and then through Congress.

  4. What would be the point? Just looking at the system it would be much more expensive than todays launches. They need to develop a reusable scramjet engine first – and that may never be. Which is presumably why they don’t discuss benefits, just glamor engineering.

    This used to be called pipe dreams, right? After a short interlude of failed .com-businesses on the “tubes”, so “tube dreams”, I guess we will have to start call them booster dreams…

  5. I’ll be astonished if NASA pursues this. They don’t have that kind of vision and leadership anymore.

  6. Would one of these work in orbit? Railgun launch would be a good way to send probes on toward other planets. Of course you would still need to get the probe to orbit to be launched. Maybe that’s what the space elevator is for.

  7. I agree that NASA probably doesn’t have the drive or leadership to pursue this anymore. It’s too bad because this actually is not a pipe dream. Electrity is a lot cheaper than rocket propellant and scramjets are a lot more efficient than rockets. Also, the system is reusable and most of the current cost of launches is in building the rocket. True it would take a lot of R&D money but I’d think it would be worth it. And yes, it could be used in orbit. However, it would be pushed backwards a little ways every time it launched something, which could cause it’s orbit to decay. It could get around this by just launching something in the opposite direction at the same time.

  8. The problem here is the vehicle would quickly decelerate as its energy is quickly dissipated away in shock wave heating.



    Dudes, like, er… do you have to send out them negative waves? Man, so many negative wave here!

  10. Like, er… “wave” should be waves. Man, when are we gonna get a preview/edit facility here?!

  11. In the Apollo era they had the vision of Kennedy, the leadership of Von Braun, and a large chunk of budget to work with provided by the congress.
    Now they have no path, no vision, and less money. But this is all stemming from the total loss of political interest in space. Clinton and Bush didn’t back or fund their plans. Obama is showing very little interest in his own, and the end result is NASA will continue to wander.

    We could build a moon base now, or we could make a better shuttle, or even work on railguns and space elevators… but unless someone, in the position to do so, puts their foot down and spells out what it should be doing, what we’ll end up with is an ongoing mess.

  12. Anyone interested in the history of the railgun, see “Birkeland’s electromagnetic gun: a historical review”, IEEE Transactions on Plasma Science, Apr 1989, Vol. 17 Issue:2, pages: 73 – 82 (abstract). You can also read his patent application online.

  13. Am I the only one wondering why the vehicle in the lead picture is pulling a 90 degree super-gee turn just as it exited the rail? Couldn’t they at least orient the rails Eastwards? Or get a better “Artist”?

    And yeah, like LC said, getting to a few km/sec at sea level is very hard on the vehicle, which will still have to have enough oomph to accelerate the rest of the delta-V. I think this makes sense only if SCRAM jets prove viable as first stages, and then the rail gets it to its ignition speed. (which is what the art shows, btw)

  14. To agree with Ivanman, this strikes similar to Goddard’s first attempts with the feedback. It is a rather novel idea, and as demonstrated in the literature, it receives attention from other branches. Anyone can look on google and see NASA has more than enough property to add this to the arsenal of space vehicles. Considering the USAF oversees the premises, vested interest could withstand any committees axe blows. Bottom line: Viable operation with sustainability for space transport and jobs alike.

  15. I think we can all agree that rail guns KICK ASS, space vehicles KICK ASS, and therefore combining the two is naturally going to kick ALL SORTS of ass.

    If that isn’t foolproof logic enough for American congressional approval for funding, then I guess I’ll have to come up with a sporting analogy…

  16. @ HSA:

    scramjets are a lot more efficient than rockets.

    Wow, no! That is the whole point!

    Not only are they considerable more expensive than rocket engines, when you put in the whole system _including shell and engine cooling_, it is on the sum less efficient. With today’s technology much less so. Just look at such summaries on the web.

    the system is reusable

    There are no reusable scramjet engines, and as I said in my previous comment it is really doubtful if there ever will be. Today’s top-of-the-art engines works for ~ 10 – 100 s.

    The material problems are “out of his world”. And no, that doesn’t mean they make good boosters.


    Dudes, like, er… negative waves

    Dude, that sounds, like, religious! A little criticism of subject, and it’s all about me. πŸ˜€

    I can turn that around and claim that I love space ventures so much that I really, really don’t want to see preventable failures that are either costly or prohibitive (there is only so much money nowadays). It’s not fair argumentation, but neither is “shoot the messenger”.

    To the positive: Heinlein’s Moon rail gun for cheap mass transit was, and likely still is, a great idea AFAIK. Scramjets, not so much outside of military applications – expensive to build, expensive to use, need rework of air regulation (sonic booms) if used for passenger traffic. The combination seems to compound problems.

    There were ideas of having air evacuated mass (for manned low-g flight, booster) launchers scaling mountains to get around shock wave heating. Those I would support precisely because they have potential for cheap launch.

  17. @ HSA:

    when you put in the whole system … it is on the sum less efficient.

    Ah, sorry, I see I made a mistake. The idea of the combination must be to come around that precisely by being able to chuck conventional engines (say, boosters) to get to scramjet speed range.

    So this may in fact be sound engineering, which in turn would eventually make use cheaper. Mind, we have to see that calculation first, the burden of proof is on their end.

    Nevertheless, the launch costs will still pivot on the problems of extending scramjet engine lifetime and demonstrating reuse. I wouldn’t hold my self-compressed breath.

  18. This basic idea here is not that new. This is in line with a set of related ideas, such as hypersonic space planes and the like which will never serve any real purpose. 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.


  19. 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).

  20. “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.


    Yeah – but it would be cool though…

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

    You sold me at loud and dirty…

  22. 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?”

  23. 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.

  24. 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.


  25. 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.

  26. 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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