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NASA Looks At Railgun-Like Rocket Launcher

CmdrTaco posted more than 3 years ago | from the spent-all-day-playing-ctf dept.

NASA 231

coondoggie writes "NASA is looking hard at a way to blast spacecraft horizontally down an electrified track or gas-powered sled and into space, hitting speeds of about Mach 10. The craft would then return and land on a runway by the launch site."

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Well, this is not a (2, Interesting)

ScrewMaster (602015) | more than 3 years ago | (#33580002)

new idea [imdb.com] , exactly, but I guess it's good to see NASA looking at other possibilities. There are many. I remember MIT doing work on alternate launch technologies back in the seventies, if not earlier. The mass driver was one (a giant electromagnetic linear accelerator) although the idea was kicked around in science-fiction long before that. My current favorite is a possibly-reusable rocket whose reaction mass is water, using heat energy provided by ground-based lasers. You could launch things into orbit all day long with a setup like that. Probably need a dedicated nuclear power plant to run the thing.

Re:Well, this is not a (1)

pilgrim23 (716938) | more than 3 years ago | (#33580048)

http://www.youtube.com/watch?v=G3yN6WfpaUQ [youtube.com] its been done

Re:Well, this is not a (2, Informative)

timeOday (582209) | more than 3 years ago | (#33580436)

Oh, it was already imagined in sci-fi novels and childrens' TV programs? Quick, somebody tell NASA before they waste a bunch of money developing a usable capability!

Re:Well, this is not a (0, Redundant)

camperslo (704715) | more than 3 years ago | (#33580806)

Yes, in addition to Fireball XL5, it was also done in When Worlds Collide [wikipedia.org] .

Re:Well, this is not a (3, Informative)

PolygamousRanchKid (1290638) | more than 3 years ago | (#33580096)

Well, I believe this critter was up and at it in the 70's at Princeton: http://en.wikipedia.org/wiki/Gerard_K._O'Neill [wikipedia.org]

Re:Well, this is not a (1)

ScrewMaster (602015) | more than 3 years ago | (#33580162)

Well, I believe this critter was up and at it in the 70's at Princeton: http://en.wikipedia.org/wiki/Gerard_K._O'Neill [wikipedia.org]

Yah. Him too. Sometimes I forget that Google is my friend.

Re:Well, this is not a (3, Insightful)

rjstanford (69735) | more than 3 years ago | (#33580350)

Ah, Heinlein, may you never cease to spin.

Anyway, the other think to consider (especially for things like laser-based launches) is that the current "spit out a ton of speed really quickly and then coast your way to orbit" approach really sucks. Even a slow nice steady boost will get you to orbit without needing to hit escape velocity.

Re:Well, this is not a (1)

findoutmoretoday (1475299) | more than 3 years ago | (#33580586)

Yes, escape velocity is about is more an expression for energy, not speed.  But the slower you go the more energy you need, and in a certain way the higer the escape velocity will be.

Re:Well, this is not a (2, Informative)

Nyeerrmm (940927) | more than 3 years ago | (#33580676)

Who coasts into orbit? Once the engine cuts off in most any launch vehicle you've achieved orbit.

Get going at the right speed from the ground and you'll enter orbit as long as there's not a mountain in the way (you'd probably want to boost your periagee afterwards though). The main reason you go up before accelerating to orbital velocity is that you get above the atmosphere and don't lose as much energy.

Re:Well, this is not a (1)

BJ_Covert_Action (1499847) | more than 3 years ago | (#33581134)

Depends on what engine and what launch vehicle you are talking about actually. Some of the larger, multi-stage vehicles will cut off the main booster or first stage before achieving a true orbit. This is usually followed by such a short coast that the primary cut-off doesn't matter. The rest of the launch vehicle will continue gaining altitude until ignition of the second stage. This isn't always the case, but, like I said, it depends on the vehicle and payload you are flying.

Re:Well, this is not a (2, Insightful)

ScrewMaster (602015) | more than 3 years ago | (#33580786)

Even a slow nice steady boost will get you to orbit without needing to hit escape velocity.

Well, sure, you could do at a walking pace ... if you had the reaction mass.

Re:Well, this is not a (3, Insightful)

BlueStrat (756137) | more than 3 years ago | (#33581004)

Ah, Heinlein, may you never cease to spin

Yes, Heinlein used this tech as a centerpiece enabling technology for Moon->Earth grain shipments (and as a kinetic weapon used against Earth once the rebellion started..."throwing rice") from a lunar penal colony in his superb science fiction novel "The Moon Is A Harsh Mistress". I highly recommend the story. Heinlein was amazing at predicting tech & science advances far, far ahead of any of his contemporaries.

In the above Heinlein novel, a rail launcher for Earth was proposed for several possible locations. These proposed locations shared certain characteristics, among them was elevation/altitude at the launcher exit point.

NASA could do a lot worse than taking some more inspiration (IIRC he's generally credited with the concept of communications satellites) from such an intellect.

Strat

Re:Well, this is not a (3, Informative)

ScrewMaster (602015) | more than 3 years ago | (#33581126)

IIRC he's generally credited with the concept of communications satellites

Nope. That was Arthur C. Clarke [lakdiva.org] , another of the grand masters of hard science-fiction.

Re:Well, this is not a (2, Informative)

InfiniteWisdom (530090) | more than 3 years ago | (#33581026)

"spit out a ton of speed really quickly and then coast your way to orbit" approach really sucks

A "nice slow steady boost" will burn an enormous amount of fuel.

Let's say your rocket weighs 1,000lb. If you provide = 1000lb of thrust your rocket will just sit there. If you provide 1001lb of thrust it'll start to accelerate every so slowly... if you provide 1002lb of thrust you'll accelerate twice as fast, but only burn ~0.1% more energy.

You'll go faster (for a given thrust) as you burn up fuel and thus shed weight, but at any weight, the higher the thrust, the smaller the percentage of energy you spend just overcoming gravity, and the more you spend accelerating the vehicle.

And don't forget, that if you got above the atmosphere "slow and steady"... if you're under orbit velocity, you're going to fall right down unless you plan on burning fuel forever.

Re:Well, this is not a (3, Insightful)

mdielmann (514750) | more than 3 years ago | (#33581146)

There are a number of reasons why rail guns are more attractive than a "steady boost".
First, we don't have anything that gives a steady boost for any reasonable amount of time at a reasonable amount of force. Rockets just don't last very long in the overall scheme of things, and laser-based propulsion systems don't have enough force to launch any appreciable payload (yet).
Second, rail guns don't require you to accelerate fuel in order to keep on accelerating. This puts an effective limit on rockets, and anything the rail gun adds pushes out our capacity based on the fuel limit.
Third, the higher/faster you're going before you start using conventional rockets will reduce fuel requirements, increase payload, or increase orbit. This is somewhat related to the second item, but not entirely. Conventional rockets require you to bring your fuel with you, which reduces payload capacity, and this compounds with the effects of being deeper in the gravity well.

Re:Well, this is not a (2, Interesting)

pixelpusher220 (529617) | more than 3 years ago | (#33581316)

Yeah but going mach 10 at ground level isn't exactly rainbows and ponies either...

This kind of (0)

Anonymous Coward | more than 3 years ago | (#33581220)

splitting annoys the hell out of me

Maybe someone should tell them... (1)

Anonymous Coward | more than 3 years ago | (#33580032)

That space is up.

Re:Maybe someone should tell them... (2, Insightful)

arkane1234 (457605) | more than 3 years ago | (#33580056)

Space is not up, it's all over, we're on a sphere.
You can go to your right and ignore gravity completely to reach space.

Re:Maybe someone should tell them... (2, Funny)

Spectre (1685) | more than 3 years ago | (#33580110)

Space is not up, it's all over, we're on a sphere.
You can go to your right and ignore gravity completely to reach space.

Damn it, we've been doing this rocketry thing the hard way.
The easy way is just to "ignore gravity"!

(Yes, I know what you mean, but it is more fun this way :)

Re:Maybe someone should tell them... (2, Informative)

Ethanol-fueled (1125189) | more than 3 years ago | (#33580610)

Ignoring gravity works when you run off the edge of a canyon or your ACME rocket runs out of propellant. You don't fall until you actually look down and remember gravity.

Re:Maybe someone should tell them... (0)

Anonymous Coward | more than 3 years ago | (#33580888)

Ignoring gravity works when you run off the edge of a canyon or your ACME rocket runs out of propellant. You don't fall until you actually look down and remember gravity.

So all the issues with overcoming Earth's' gravity well since the inception of the manned space program have been due to astronauts not keeping their eyes on the stars?

Huh. Explains a lot.

Re:Maybe someone should tell them... (2, Funny)

spazdor (902907) | more than 3 years ago | (#33581080)

NASA should hire people with surprising bodies and/or opinions to jump out and reveal/explain them, providing a needed distraction at the critical moment.

Re:Maybe someone should tell them... (3, Insightful)

ScrewMaster (602015) | more than 3 years ago | (#33580066)

That space is up.

Up is relative. Space is away.

Re:Maybe someone should tell them... (0)

Anonymous Coward | more than 3 years ago | (#33580400)

If I've learned one thing from Superman, it's that the formula for flight is up, up, and away. Therefor it is 2/3 up, and 1/3 away.

Re:Maybe someone should tell them... (1)

ScrewMaster (602015) | more than 3 years ago | (#33580928)

If I've learned one thing from Superman, it's that the formula for flight is up, up, and away. Therefor it is 2/3 up, and 1/3 away.

Yes, but I understand that for other countries the formula may be different. Remember, he was all about Truth, Justice and the American way. So, for example, when Russia wants to launch a spacecraft, they have to use Up, Up, and the Soviet way, which as we all know, is somewhat different.

Re:Maybe someone should tell them... (2, Insightful)

AnonymousClown (1788472) | more than 3 years ago | (#33580094)

That space is up.

You see, they'll fire the spacecraft horizontally and it'll fly really really fast until it falls off the World into orbit.

Re:Maybe someone should tell them... (3, Insightful)

butterflysrage (1066514) | more than 3 years ago | (#33580148)

so basically the trick is to fall down and miss?

Re:Maybe someone should tell them... (4, Insightful)

GigG (887839) | more than 3 years ago | (#33580760)

"Fall down and miss" is orbital dynamics at is most basic.

Re:Maybe someone should tell them... (4, Informative)

sconeu (64226) | more than 3 years ago | (#33580156)

You're being facetious, but that's exactly what would happen.

Re:Maybe someone should tell them... (0)

Anonymous Coward | more than 3 years ago | (#33580920)

Whoosh!

(that's the sound the craft would make going by overhead, nothing like the sound of his humor sneaking by you disguised as facetiousness..)

Re:Maybe someone should tell them... (1)

godel_56 (1287256) | more than 3 years ago | (#33581206)

Whoosh!

(that's the sound the craft would make going by overhead, nothing like the sound of his humor sneaking by you disguised as facetiousness..)

At Mach 10 it'd be more of a Bang! than a Whoosh!, probably taking out your windows in the process.

Re:Maybe someone should tell them... (1)

Ironhandx (1762146) | more than 3 years ago | (#33580924)

This needs more +1 insightful as well as some +1 informative. This is exactly what would happen. In fact rocket launches already take some advantage of this fact. Going absolutely straight up would cause a whole world of hurt on the vertical frame and require extra fuel. Launching on an angle mitigates this. Basically you're traveling further to get out of the atmosphere but using less energy overall. If ground based launch facilities can get it to 600 m/h and then a scram jet can get it to escape velocity it could be a much much more efficient model.

They've done very little research into the subject other than some launch off the back of a jumbo jet tests over the last 20-30 years. There has to be a better way than just brute force high energy rocket fuel.

Re:Maybe someone should tell them... (1)

Yvan256 (722131) | more than 3 years ago | (#33580298)

Up and at them!

NASA still cannot do simple math. (2, Interesting)

drcheap (1897540) | more than 3 years ago | (#33580068)

"...hitting speeds of about Mach 10."

"Starr noted that electric tracks catapult rollercoaster riders daily at theme parks. But those tracks call for speeds of 60 mph -- enough to thrill riders, 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."

Mach 10 = 600mph ???

Re:NASA still cannot do simple math. (-1, Troll)

Anonymous Coward | more than 3 years ago | (#33580084)

In related news http://tinyurl.com/bebe

Re:NASA still cannot do simple math. (1)

Tekfactory (937086) | more than 3 years ago | (#33580218)

Perhaps it only needs to get up to 600 MPH before the Scramjet takes over.

If you read any of the articles on their scramjet tests, they need supersonic airflow to create the pressure inside the engine. Once ignited, Mach 10 wouldn't be outrageous for a Scramjet.

http://www.shortnews.com/start.cfm?id=63070 [shortnews.com]

Unfortunately escape velocity isn't Mach 10, but for early test platforms, we already have the tech necessary to do what's in the proposal, and what we might learn from repeated launches and fine tuning the scramjet, seems promising.

Re:NASA still cannot do simple math. (1)

durrr (1316311) | more than 3 years ago | (#33580288)

http://en.wikipedia.org/wiki/Scramjet#Theory [wikipedia.org]
Scramjets don't need supersonic airflow, they only need a dynamic pressure that is in the right interval. If you look at the equation in the wiki link you'll see that it will be able to operate at lower speeds at lower altitude, in fact, it will not be able to operate at mach 10 at low altitude at all, but would constantly speed up as it gains altitude to keep an approximately constant dynamic pressure.
Seems elegant enough for me.

And the scramjet would only be a middle stage vehicle, it would carry a rocket craft in addition to put things into orbit.

Re:NASA still cannot do simple math. (4, Informative)

vlm (69642) | more than 3 years ago | (#33580662)

Once ignited, Mach 10 wouldn't be outrageous for a Scramjet.

Well, that seems a bit optimistic for a device that has been successfully flown, what, twice? Its kind of like planning the Boeing 777 the day after the wright brothers first flight.

The real killer with all these "hybrid" lifter designs is they are all ignorant of the virtually unknown 666 rule.

The 666 rule is that Mach 6 (which is tricky for an air breathing aircraft) at 60000 feet (again, tricky) is a whopping 6% of the way to orbit.

So, if, in your wildest dreams, you can simultaneously achieve mach 6 at 60Kft, which would be quite the noteworthy achievement, you've still got 94% of the way to go.

Alternately, you could take the required second stage, and make the fuel tank at least 6% bigger and skip all this air breathing foolishness.

Re:NASA still cannot do simple math. (1)

bcmm (768152) | more than 3 years ago | (#33581172)

Perhaps it only needs to get up to 600 MPH before the Scramjet takes over.

Well, unless something is taking over, this is just a big artillery piece: escape velocity is rather higher than mach 10 [wolframalpha.com] .

Re:NASA still cannot do simple math. (1)

phantomfive (622387) | more than 3 years ago | (#33580238)

The launcher would need to reach at least 10 times that speed

"At least"....for all those times when you can't quite do the math!

Re:NASA still cannot do simple math. (1)

drcheap (1897540) | more than 3 years ago | (#33580504)

The launcher would need to reach at least 10 times that speed

"At least"....for all those times when you can't quite do the math!

Ahh yes, I seemed to overlook the fact that (approx)7600 >= 600. I guess they were correct all along.

Well enough about that, I have to go check out that great "up to 100% off" sale at my local consumer electronics store.

Re:NASA still cannot do simple math. (1)

Prune (557140) | more than 3 years ago | (#33580304)

The author probably rounded down to 100 times the speed and dropped a zero, possibly as a typo. It's the only plausible explanation I could come up with for this error.

Re:NASA still cannot do simple math. (1)

X0563511 (793323) | more than 3 years ago | (#33580530)

Only at a ridiculously low pressure...

(mach is dependent on the speed of sound, which is dependent on the atmospheric temperature and pressure)

Re:NASA still cannot do simple math. (0)

Anonymous Coward | more than 3 years ago | (#33581110)

I guess 10 x 60mph = 7,612. Maybe there was a conversion problem there.

    One team, the ones who got to ride roller coasters for the sake of science, were using base 10 and American measurements.

    Another other team stayed back in the lab. They decided to measure the speed as furlongs per sidereal hour, and all the numbers were done in at base 126.

Re:NASA still cannot do simple math. (1)

ratboy666 (104074) | more than 3 years ago | (#33581174)

Maybe just missing a "0" -- should be "100 times", but even that's low. Mach 10 is around 6600 mph "where the jets go" and 7700 at sea level.

Of course, escape velocity is 25,000 mph (no friction from the air factored in), but (and I didn't read tfa) it seemed like they want to come back (maybe like a really big boomerang?), so I don't think it matters.

Just for grins, if the thing is launched at a 45 degree angle, it should reach a maximum height of approximately 185 miles, and travel a distance of around 750 miles (every done in US measurements for you).

It will do that in 8 minutes. All presuming no air, which does tend to mess with the calculation a bit :) Still, to accelerate to Mach 10 on a rail? That's something I really want to see! If the projectile weighed in at 1kg (2.2 lbs), the resulting hit would be equivalent to an explosion of 3 lbs of TNT (again, no air resistance factored in).

That's all I got... now I might go read TFA...

NASA plays too much Quake (1)

zero_out (1705074) | more than 3 years ago | (#33580118)

Railguns? Rocket launchers? Too much Quake I say.

Re:NASA plays too much Quake (1)

X0563511 (793323) | more than 3 years ago | (#33580132)

Indeed. Isn't this a mass driver?

Re:NASA plays too much Quake (1)

ScrewMaster (602015) | more than 3 years ago | (#33580152)

Indeed. Isn't this a mass driver?

Or a Gaussrifle.

Re:NASA plays too much Quake (1)

X0563511 (793323) | more than 3 years ago | (#33580196)

Nope. It might be a Gaussian Accelerator or something like that, but it's no rifle. I'd hate to be spun like that on launch :)

Re:NASA plays too much Quake (0)

Anonymous Coward | more than 3 years ago | (#33581056)

You'd end up nothing more than a Gaussian blur.

Re:NASA plays too much Quake (1)

ScrewMaster (602015) | more than 3 years ago | (#33581164)

You'd end up nothing more than a Gaussian blur.

Yes, but you could use a CSI-style reverse algorithmic [crimelab.nl] to recover the pilot's data.

Let's hope NASA is better at math than TFA (3, Informative)

Just_Say_Duhhh (1318603) | more than 3 years ago | (#33580120)

According to TFA, the sled will be "hitting speeds of about Mach 10." That's fast, but then the TFA says, "electric tracks catapult rollercoaster riders daily at theme parks. But those tracks call for speeds of 60 mph -- enough to thrill riders, but not nearly fast enough to launch something into space. The launcher would need to reach at least 10 times that speed"

Sorry, but 10x roller coaster speeds isn't close to Mach 10.

NASA is on to something interesting here. It would seem that MagLev [wikipedia.org] is required (no wheels can handle that speed), and it would be interesting to see what kind of acceleration they can get out of LIM's [wikipedia.org] . Rocket propulsion seems a waste in this application. It might help bullet-train technology, and we can get some new spin-off inventions from NASA.

Put the railgun in orbit (2, Insightful)

mangu (126918) | more than 3 years ago | (#33580358)

Sorry, but 10x roller coaster speeds isn't close to Mach 10.

And even Mach 10 isn't enough, orbital velocity is close to Mach 25. You cannot run at that speed inside the atmosphere, there's no material that could withstand the heat.

I've seen a much better idea proposed. Put that electric accelerator track in orbit. The energy needed to reach orbital altitude is much less than the energy needed to accelerate to orbital speed.

One could launch the spacecraft vertically to an interception with the accelerator track, then it would catch the track and get the needed horizontal speed while already outside the atmosphere.

Re:Put the railgun in orbit (1)

metrometro (1092237) | more than 3 years ago | (#33580468)

TFA suggests that the Mach 10 will be to get some scramjets online, which will then boost to high atmosphere, and then pop out a small second (third?) stage rocket.

Re:Put the railgun in orbit (1)

Just_Say_Duhhh (1318603) | more than 3 years ago | (#33580534)

But when you catch the "track" to gain orbital velocity, wouldn't that just decay the track's orbit? You'd have to keep adding energy to the "track." I thought the rail gun concept was trying to avoid having to generate all that energy in space (thereby avoiding the need to launch all that extra weight)?

Re:Put the railgun in orbit (1)

mangu (126918) | more than 3 years ago | (#33580566)

But when you catch the "track" to gain orbital velocity, wouldn't that just decay the track's orbit?

Sure, but you would also use the track to decelerate spacecraft from orbital velocity to land on earth, which would cause the track to gain velocity.

Re:Put the railgun in orbit (3, Funny)

X0563511 (793323) | more than 3 years ago | (#33580580)

... in which case Newton's Laws would adequately describe the reasons why your ultra-expensive orbital mass driver is now an ultra-expensive meteor shower.

Re:Put the railgun in orbit (1)

X0563511 (793323) | more than 3 years ago | (#33580616)

(realized i should explain for those that don't get it)

The force applied to the craft by the accelerator will also act against the accelerator. Firing the right way, it would drop the accelerator right out of orbit (it would impart it's velocity into the craft, leaving it with less than needed to maintain orbit, crashing down). Fired the other direction, and the exact reverse would be seen - the accelerator would "push" off of the craft, accelerating and gaining altitude, but the craft would then fall quite ungracefully.

Re:Put the railgun in orbit (1)

Kilrah_il (1692978) | more than 3 years ago | (#33580756)

OK, so it's a one-time use accelerator, but it's still good, nay?

Re:Put the railgun in orbit (1)

Somegeek (624100) | more than 3 years ago | (#33581294)

How does something going 7 km/sec catch something going zero?

Colliding, I can see. Gently catching and accelerating up to the same speed, I don't see.

Re:Put the railgun in orbit (0)

Anonymous Coward | more than 3 years ago | (#33580780)

Do you seriously have only a small iota of critical thinking skills?

Think about it for one second. You do not need to do all of your acceleration to Mach 25 on the track. You accelerate to Mach 10 and then the vehicle is released, and it is carrying additional propulsion which then takes it into orbit at the needed velocity.

Your proposal sucks compared to what is brought up in the article (no surprise, space scientists versus internet poster). There is so many fundamental things wrong with putting an electrical accelerator track into orbit to help space craft launch.

First: If the track is to be in orbit, the track itself must have a orbital velocity. Therefore to 'catch' the track as you say, the space craft must be going faster than it. The space craft will then have orbital velocity by the time it catches the track. Since the point of the track is to accelerate a vehicle to orbital velocity it is no longer useful in this position. Even if you have the track catch the vehicle, it doesn't make any sense. Consider the deltaV between the shuttle and the ISS when it docks. There is not much of a difference.

Second: Since the initial idea sucks since the track makes itself obsolete, lets consider that the track is a staging point to go from orbital velocity to a planetary exploration path. However, this idea also sucks. The track itself will probably be light. All you need is some rail, power supply/generation, and energy storage (probably some gigantic capacitors). It also needs to be light (low mass) to actually be built in space, because heavy stuff in space is incredibility expensive. This means that when your spacecraft is launched on the rail, the rail gets rocketed in the opposite fucking direction. Oops! For example, the ISS, the biggest thing we've ever built in space, and the MOST EXPENSIVE THING humans have ever built by a FACTOR OF 10 over then next expensive item, weighs 820,000lbs. Which sounds like a lot until you see that the space shuttle orbital vehicle weighs ~240,000lbs.

Re:Put the railgun in orbit (1)

BJ_Covert_Action (1499847) | more than 3 years ago | (#33581226)

Well that might defeat the purpose of such a system. The whole idea behind rail launching anything is to make launches cheaper and simpler. Having to use a rocket stage, to get to low orbit, to rendezvous with an orbital track, to propel a vehicle to its intended orbit probably doesn't match either of those criteria. Besides, the assumption that we would be launching from a track surrounded by atmosphere is pretty unimaginative. The way I see something like this working would involve building more of a tube than a track. Keep the vehicle suspended in the tube using a crapton of really big magnets. Keep the tube vacated of any and all atmosphere (keep it near vacuum). Fire up concentric rings of more magnets that would steadily push the levitating vehicle forward in the tube faster and faster. Ensure that the tube is long enough to get the acceleration and velocity necessary to reach a decent LEO parking orbit and there you have mankind's very first spacegun. Now, would this project be simply or easy? Not at first, no. But if we start doing research with high speed track systems, and taking data regarding the very same aero forces that you mention now, then a few decades down the line we might be better suited to build a spacegun off the coast of California...or wherever.

Re:Let's hope NASA is better at math than TFA (1)

Fnord666 (889225) | more than 3 years ago | (#33580444)

According to TFA, the sled will be "hitting speeds of about Mach 10." That's fast, but then the TFA says, "electric tracks catapult rollercoaster riders daily at theme parks. But those tracks call for speeds of 60 mph -- enough to thrill riders, but not nearly fast enough to launch something into space. The launcher would need to reach at least 10 times that speed"

Sorry, but 10x roller coaster speeds isn't close to Mach 10.

I think he is looking for more like 128x. Furthermore TFA calls for reaching that speed in two miles. Anyone want to figure out the acceleration needed? There wouldn't be anything left but goo.

Re:Let's hope NASA is better at math than TFA (1)

jdgeorge (18767) | more than 3 years ago | (#33580828)

You're expecting a particularly informed, insightful article about rocket science in NetworkWorld? Seriously?

Re:Let's hope NASA is better at math than TFA (2, Interesting)

movrev (1901148) | more than 3 years ago | (#33580996)

Accelerating up to supersonic speeds on a maglev track is quite problematic from a controls/stability perspective. The generated shock waves will bounce off of the ground/track creating some interesting ground effects which will mess up the launch unless properly controlled. I'm sure their proposal is to get the sled up to about Mach 1, at which point they'll be able to take off with a ramjet engine. Once they reach around Mach 5 in the atmosphere, they could transition into a scramjet configuration which can theoretically allow them to reach orbital speeds. This specific problem has been in NASA's mind for a number of years now. I used to work on this precise thing in collaboration with them around 5 years ago.

Re:Let's hope NASA is better at math than TFA (1)

ISoldat53 (977164) | more than 3 years ago | (#33581058)

It's all that metric to inches stuff NASA can't seem to get right.

Re:Let's hope NASA is better at math than TFA (1)

FishTankX (1539069) | more than 3 years ago | (#33581120)

You could do even better by putting a good part of the maglev track in a vacuum. This would allow frictionless acceleration and possibly allow you to achieve ludicrous speeds. Possibly subjecting the package to be launched to hypersonic wind fronts for a lesser period of time.The trick would be the transition zone though. Maybe an airlock that's programmed to open at the correct time?

Net Assets' launcher? (1)

knarf (34928) | more than 3 years ago | (#33580186)

Hey, it looks like someone read that Net [bussjaeger.org] Assets [smashwords.com] novel by one Carl Bussjaeger but decided that the trick could be done without using the libertarian sauce Bussjaeger pours over it. Bussjaeger ended up deciding that a rail gun or other tracked thing would not work so he went with a supersonic ground effect launcher.

Finally... (3, Insightful)

Prune (557140) | more than 3 years ago | (#33580256)

After all the hype that we've been hearing over the years about rail-guns and seeing a few military and hobbyist demos on video sites, this one piece of near-former sci-fi may be finally coming to fruition as a usable approach. It's a great example of the sort of thing that had to wait for technological improvements and refinements, rather than a fundamental scientific or technological breakthrough, and is the convergence of several technologies. I'm encouraged to see more progress on such things which seems to have in recent years been eclipsed by information technology's faster cycles and overhyping in media (and I say this as someone who makes his living as a software engineer).

Re:Finally... (1)

ScrewMaster (602015) | more than 3 years ago | (#33580574)

After all the hype that we've been hearing over the years about rail-guns and seeing a few military and hobbyist demos on video sites, this one piece of near-former sci-fi may be finally coming to fruition as a usable approach. It's a great example of the sort of thing that had to wait for technological improvements and refinements, rather than a fundamental scientific or technological breakthrough, and is the convergence of several technologies. I'm encouraged to see more progress on such things which seems to have in recent years been eclipsed by information technology's faster cycles and overhyping in media (and I say this as someone who makes his living as a software engineer).

I, well, I agree. And make my living the same way. I've also been a science-fiction fan since I was a kid (Clarke, Heinlein, Norton, Silverberg, Harrison, Dick, you name it I probably read it) and honestly I've been disappointed by the past forty years, at least so far as near-space development is concerned. I thought, well, I'd hoped we would be way further along than we are, and had we continued the pace of development after the end of the Apollo program we would have be. But we chickened out, let our leaders dilute the vision and throw away the many of the gains we made during the sixties.

I'm always flabbergasted at the people who seriously believe that investment in space is a waste of time and money. Try to tell them that the economic benefits from that investment outweigh the costs, and they laugh at you, and say we would be better off spending it on "social programs." Hell, what the world has gained from, say, advanced weather prediction alone would pay for the space program.

The big problem is determining where to spend your resources in order to get the most ROI. Hell, for that matter, defining the ROI is something many people, politicians especially, simply can't agree.

Re:Finally... (1)

Mr. Slippery (47854) | more than 3 years ago | (#33581326)

honestly I've been disappointed by the past forty years, at least so far as near-space development is concerned. I thought, well, I'd hoped we would be way further along than we are, and had we continued the pace of development after the end of the Apollo program we would have be. But we chickened out, let our leaders dilute the vision and throw away the many of the gains we made during the sixties.

The "vision" of our leaders during the 1960s was 1) let's beat those darn Russkies at the propaganda game, and 2) let's be able to deliver a nuclear warhead to any point on the surface of the earth.

That's it. We've got the ICBMs, and our big propaganda conflict these days is with guys living in caves.

There's just not much reason to go into space. Satellites and robot probes, sure, but we've had many of those over the past 40 years, so that not what you -- not what we SF fans -- want. We want Man In Space. But there's just nothing you can have them do up there in orbit that's worth the expense of putting them there, except maybe repair the satellites -- and even there robots will be able to do the job cheaper in a few years. And there's not a lot of romance in being a free-fall Maytag repairman.

(I am not sure if I am playing devil's advocate here or not.)

Try to tell them that the economic benefits from that investment outweigh the costs, and they laugh at you, and say we would be better off spending it on "social programs." Hell, what the world has gained from, say, advanced weather prediction alone would pay for the space program.

If you want economic benefits on earth, you put your money here. Spin-off is a lousy argument. If you want faster computers, it makes much more sense to fund computer research than to fund a trip to the moon so some test pilot can plant a flag and have a photo op, on the theory that we'll need faster computers to guide his trip.

Sure, weather satellites are valuable; that doesn't justify manned moon shots.

If the justification for the manned space program is that it's inspirational, than it's just performance art -- put it under the NEA. If it's supposed to create jobs, it's just make-work, and we can instead have make-work projects that address pressing problems like renewable energy.

Re:Finally... (1, Interesting)

Anonymous Coward | more than 3 years ago | (#33580700)

No. Sorry to disappoint all the folks who just don't get it, but this is not going to be a railgun. As a software engineer, your confusion on this is certainly excusable -- after all, even SF and video games, by and large, seem determined to make sure nobody understands what a railgun is.

At present, railguns suck -- even the Navy's version (the only thing close to being productized) is anticipated to need rail replacement/rebuild every dozen shots or so at first, with the hope that they can improve on that once it's operational. That's entirely feasible for a weapon that fires what's essentially a metal slug (perhaps a few hundred or thousand dollars) with range, accuracy, and damage on par with a $500,000 cruise missile; the money saved more than allows for having a bunch of replacement rails (only a few feet long) on hand, and replacing them can be done fairly quickly. They suck, it's just that cruise missiles suck even more.

But on a miles-long track, replacing or refinishing the rails is an insanely slow and expensive undertaking -- not that it's completely infeasible (after all, rockets, short of SSTO, suck pretty hard too), but you'd have a hard time solidly beating rocket launch rates and costs, and with the enormous capital outlay to build the launch ramp, you've gotta be sure you can undercut the competition and make it back. No, the reason it's called "railgun-like" in TFT, and "an electrified track" in TFS, rather than simply a railgun, is because it's going to be a linear induction motor or similar (in fact, probably a LIM to get up to Mach ~2, then a scramjet the rest of the way), not a linear homopolar motor, or (as the LHM with a projectile-armature is commonly known) railgun.

Oh, and FWIW, another quite interesting launch-ramp concept is the BFG [tbfg.org] 's ram accelerator concept -- IMHO the most promising of the various alternative-launch-schemes-with-websites (aka crazy bastards looking for VC). Highly recommended reading for alternative launch geeks, especially those with enough sense to realize they won't see a geosynch space elevator in their lifetime...

Re:Finally... (1)

HawaiianToast (618430) | more than 3 years ago | (#33580714)

Well, the application forms for funding are coming to fruition at least...

Re:Finally... (0)

Anonymous Coward | more than 3 years ago | (#33580900)

may be the only light rail the US ever sees.

Re:Finally... (2, Interesting)

DerekLyons (302214) | more than 3 years ago | (#33581178)

After all the hype that we've been hearing over the years about rail-guns and seeing a few military and hobbyist demos on video sites, this one piece of near-former sci-fi may be finally coming to fruition as a usable approach.

Nope, this piece of "near former sci-fi" is just as far from fruition as it ever was.
 

It's a great example of the sort of thing that had to wait for technological improvements and refinements, rather than a fundamental scientific or technological breakthrough, and is the convergence of several technologies.

It's a great example of people not learning from the past and re-inventing the square wheel because now they have the tech to make carbon fiber square wheels instead of those old fashioned wooden ones.
 
But they're still square wheels.
 
The basic problem with a railgun is that it give only a fraction of the velocity required - and it does so only in one plane. (Orbital velocity has both a horizontal and a vertical component, railguns provide velocity only in the horizontal, cannons only in the vertical.) So you end up still needing a substantial rocket stage in order to provide the missing velocity - but now that rocket stage needs to be reinforced (thus increasing parasitic mass) in order to stand the stresses of being handled (while fueled) horizontally and of having to maneuver while still deep in the atmosphere[1] and insulated against structural heating from friction due to it's high speed low in the atmosphere... You end up not gaining anything over the conventional approach.
 
Railguns don't work because we lack some wonder technology for the gun - they don't work because the structural sums don't add up for the booster. Any materials improvement that you could apply to a railgun boosted launcher, you can also apply to a conventional launcher, which still leaves the railgun launcher trailing in performance and cost.
 
Railguns and a host of other alternative launch schemes look so simple and obvious that people simply cannot convince themselves that they don't work. So, they keep throwing money and tech at the problem convinced that this time it will work, it's so simple it just has to work. So NASA will waste a couple of hundred million dollars dicking around with the new gun - and then they'll discover the problem of booster design (again). And just like the last dozen times they've done this, the project will quietly be dropped.
 
Until the next time someone comes up with a PowerPoint presentation showing how this time it will be different.

[1] If you ever watch a rocket launch, you'll notice it goes more-or-less straight up for a couple of miles before starting to pitch over - there's a reason for that.

Re:Finally... (1)

interval1066 (668936) | more than 3 years ago | (#33581192)

Then after the professor trots the dancing girls out of the giant bullet-capsule the moon will grimace and wince as the bullet-capsule will be stuck in one of his eyes.

jellied brains (1)

FranTaylor (164577) | more than 3 years ago | (#33580292)

Oh the acceleration! Hopefully this is not for manned flights!

Re:jellied brains (0)

Anonymous Coward | more than 3 years ago | (#33580728)

This might blow your mind...

http://en.wikipedia.org/wiki/Liquid_breathing

I just wonder what kind of sonic boom would result from a Mach 10-25 flight, or if they are planning on building this up a mountain. And if you build a longer track, you have lower G-forces.

And I wonder if the mag-lev tech would be good enough to accelerate a lot of weight, or if they would still need booster rockets. Interesting concept, and it could make space travel quicker.

Re:jellied brains (1)

ISoldat53 (977164) | more than 3 years ago | (#33581082)

Sounded like they are planning on building it at the Cape Kennedy launch facility.

One faster (2, Funny)

Anonymous Coward | more than 3 years ago | (#33580342)

Well you could you know, make it one faster, you know go up to Mach eleven. Well, it's one faster, isn't it? It's not ten. You see, the Russians, you know, will be launching at Mach ten. You're on Mach ten here, all the way up, all the way up, all the way up, you're on Mach ten on your magnetic sled. Where can you go from there? Where? Nowhere. Exactly. What we do is, if we need that extra push over the cliff, you know what we do? Mach Eleven. Exactly. One faster.

When Worlds Collide (1)

hodagacz (948570) | more than 3 years ago | (#33580352)

I guess George Pal got it right.

A rail gun accelerating objects to mach 10 (1)

Just_Say_Duhhh (1318603) | more than 3 years ago | (#33580354)

built alongside the crawlerway? Just when I thought real estate prices in the Space Coast of Florida couldn't drop any lower, now we have sonic booms being generated at ground level just a couple miles from Merritt Island and Cocoa Beach.

In related news, I just opened "Space Coast Window Repair."

Mach 10 (1)

rbanffy (584143) | more than 3 years ago | (#33580374)

So, the rail takes the x-43-like launcher to 600 (10x60) mph? That's not nearly enough to ignite the engine. Assuming it gets 5 times as fast (3000 mph should be enough to ignite it) it will be very close to the ground. 3000 mph close to the ground must generate non-trivial amounts of heat (and broken windows). Ignore that (because the launcher appears to have SR-71-like engines) for a moment and imagine the launcher now has to propel itself to the upper atmosphere, where it reaches Mach 10 (something we never did on an air-breathing engine) points itself upward (perhaps getting rid of more atmosphere) and launches the expendable stage. The launcher then glides back to the ground and lands safely.

Am I the only skeptical one here?

I am glad NASA is thinking on stuff, but, seriously, they could as well think about viable stuff. They don't need milestones like these - they need, as one expert once said, "inchstones".

Payload Weight (1)

decipher_saint (72686) | more than 3 years ago | (#33580414)

I have no idea how heavy the Shuttles (or Soyuz capsules for that matter!) are even without the massive fuel tanks/rockets but I imagine this will take a lot of energy to get the job done.

I think it's a great project for two main reasons:
1. Figure out how to generate and store a big chunk of energy.
2. Use it to accelerate and object to escape velocity.

There is so much potential for discovery in both areas it boggles the mind.

If they're launching horizontally... (1)

jenningsthecat (1525947) | more than 3 years ago | (#33580448)

...then by definition they're launching at a tangent to the earth's surface. This means that they'll have to punch through a lot more atmosphere than they would have to with a traditional perpendicular launch. I wonder how much they're really gaining with this strategy.

Re:If they're launching horizontally... (1)

vlm (69642) | more than 3 years ago | (#33580754)

...then by definition they're launching at a tangent to the earth's surface. This means that they'll have to punch through a lot more atmosphere than they would have to with a traditional perpendicular launch. I wonder how much they're really gaining with this strategy.

Since they are depending on a miracle occurring in engine technology, maybe they are expecting an equal miracle to occur in wing technology, to get a high mach number wing with a slow glider like lift to drag ratio so they can pull up at the end of the launch rail thing. Piling on that many pipe dreams, they may as well ask for a flying unicorn.

Fast enough to reach orbit is... (1)

gurps_npc (621217) | more than 3 years ago | (#33580570)

fast enough to kill a human. I may be mistaken, but I am pretty sure that is the case. Current fighter pilots reach speeds high enough to black out (and/or red out). At said speed, they can't reach orbit. I can see no way for us to create a purely (or even mostly) land based launch system to supply enough energy in a short period of time to reach escape velocity. Not even if you built it on the Tibetan plateau that reaches 5000 meters above sea level.

To keep the human alive, we need a slower, longer burn, which requires an engine on the craft, not on the ground.

Re:Fast enough to reach orbit is... (1)

tibit (1762298) | more than 3 years ago | (#33580796)

You black out when you fly a curved path -- that's the only way to generate sufficient accelerations. To merely fly fast, all you've got is the mass of the aircraft (and your butt) counteracted by the engine thrust. Gives a nice buttkick, but not nearly enough to cause any distress.

The fighter pilots black out when they make turns, and for that they don't need to fly fast at all. You can easily black out on an aerobatic biplane with a prop engine.

Re:Fast enough to reach orbit is... (1)

SteveAstro (209000) | more than 3 years ago | (#33580816)

SPEED doesn't kill you, acceleration might. Bear in mind you are currently moving at at least 1000 MPH.

Re:Fast enough to reach orbit is... (0)

Anonymous Coward | more than 3 years ago | (#33581300)

Intertial dampers, fool!

Sci Fi had it first (0)

Anonymous Coward | more than 3 years ago | (#33580584)

About damn time. Heinlein suggested it, the US has been capable of it for 40 + years. But I guess a rut is a rut.

What about launch loops? (1)

postermmxvicom (1130737) | more than 3 years ago | (#33580604)

If NASA starts looking at alternatives, I'd be interested in what they say about Launch loops [wikipedia.org] . They always looked cool to me. Maybe one day NASA will look at those also?

Are rail guns like lasers (1)

SnarfQuest (469614) | more than 3 years ago | (#33580636)

re rail guns enough like lasers that they need shark keepers?

Why at sea level? (2, Insightful)

Anonymous Coward | more than 3 years ago | (#33580930)

Why would they do this at sea level? This should be done somewhere in the American West, at altitude. At 10K feet there is a heck of a lot less air resistance. Could be done on one of the Air Force ranges for sonic boom sake.

Re:Why at sea level? (1)

istartedi (132515) | more than 3 years ago | (#33581088)

I was thinking this too. Edwards AFB maybe? Hmmm... only about 2500 ft apparently. We can get to 5000 feet easily on a lot of places out west though, and I'm sure the military already controls a lot of flat land at that altitude or greater. 10000? I don't think you can do that without the extra hassle of building on very steep land.

Friction? (1)

MaWeiTao (908546) | more than 3 years ago | (#33580946)

I'm a complete layman here, but it seems to me that friction from air would be a serious problem at the speeds a vehicle would have to be propelled off this launcher. By the time conventional rockets have achieved a significant speed they're already fairly high in the atmosphere. I can't see a launch tower being practically ramped up high enough to overcome these effects. The vehicle would have to survive the stresses of heat and friction at launch and reentry. There's also the matter of drag kicking in before the second rocket fires. And I suppose another question is how many Gs would be placed on a vehicle using this method compared to traditional launches. This sounds comparable to firing a bullet from a gun which seems like it would be a rather violent launch.

Maybe it's all a non-issue. On the surface it seems really neat.

Re:Friction? (1)

ScrewMaster (602015) | more than 3 years ago | (#33581098)

This sounds comparable to firing a bullet from a gun which seems like it would be a rather violent launch.

Depends. If you used a linear accelerator (e.g. a mass driver) of sufficient length, you could accelerate at one G. You'd probably want more than that, though, to keep the size of the launcher manageable.

That's so 1980's.... (1)

Jedi Holocron (225191) | more than 3 years ago | (#33581012)

I guess it's Back to the Future...or is that Past...

Old idea, see "The Moon Is A Harsh Mistress" (0)

Anonymous Coward | more than 3 years ago | (#33581268)

by Robert Heinlein

http://en.wikipedia.org/wiki/The_Moon_Is_a_Harsh_Mistress [wikipedia.org]

It's a real shame the government is so darn corrupt, incompetent and shortsighted or we'd probably have this level of technology already. Oh well, I guess mansions and yachts for playpeople are far more important.

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