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Magnetic Space Launches
DiZNoG writes "This CNN article discusses NASA experimenting with the idea of using Mag-Lev technology to launch payloads into space. Mentioned in the article is that the U.S. Navy is working on the technology for it's aircraft carriers to launch fighters. Unfortunately the NASA project is horribly underfunded ($30,000) for research. Cool technology, let's hope that the Navy research gets us a step closer to not burning all that Oxygen and Hydrogen to get to space...
Although this technology is by far a better way to get payloads into space, all the energy used to create sufficient electricity to do so would make this method of launch just as costly as the previous. Mag/Lev is an excellent suggestion, after we make more breakthroughs in superconductivity and emf it will become a spectacular solution.
Of all the Universal Constants, here's one I know: Nice guys finish last
I'm wondering how much of the benefits of this is in the acceleration/speed they hope to achieve in a small space, versus the height they want to reach. I'm an idiot on the subject, admittedly (who's an expert, anyhow?), but which is more unrealistic, building an EM rail that reaches near orbit, or trying to accelerate 100s of tons verticaly to reach a high speed? (I'm still going to assume that they'll use rockets to reach orbit, and not 100% rely on the rail for the energy.)
If I remember a while back, I could have sworn I saw some sort of launch system in either a computer animation demonstration or in a game itself.
This idea would be interesting to apply into space as there is very little friction in space to slow things down. Why not make an addon on to the IIS to launch vehicles to Mars or Venus via this launch method? If the track was long enough it could go faster than convention rocketry. And in fact, less fuel would be needed on the vehicle since the mag-lev was the device that launched it.
By using mag-lev for both takeoffs and landings, the Navy could presumably have takeoffs and landings on the same boat very close to each other, without the complexity of the current mechanical system. But, of course, mag-levs are useless for landings from spacee, since spacecraft usually don't have wings - and those that do can just use parachutes for losing speed.
Though I guess you'd have a hell of an "electro-magnetic signature".
pr0n - keeping monitor glass spotless since 1981.
I didn't think they launched rockets exactly vertically. To get the orbital speed right, they go off at an angle - possibly after goign straight up for the most dense part of the atmosphere. I suppose for geostationary sattelites they don't need quite the rotation (and they need to go further up). Easier to explain with a picture, but no can do here.
This is why they like to launch from near the equator and always orbit in the same direction as the earth - you get a substantial boost (900 miles an hour according to Monty Python).
This sig made only from recycled ASCII
They have plenty of foresitgh...
Launching that way makes you only cause large amounts of impact craters. something we are really good at putting on mars. How are you going to decelerate? if you launc, in space, with much more energy than you can overcome with the device it's self you will never stop until impact. Atmospheric breaking works only at slower speeds, the speed you are talking about would probably cause impact damage upon hitting the atmosphere of mars.
Do not look at laser with remaining good eye.
Give the spacecraft a push, so you can wait until a certain hight before you turn on the rockets.
This is great if the rockets then actually ignite. Otherwise you would look kind of silly just throwing a spacecraft high into the air and then just watching as it drops :-)
By the way - to all those posts discussing geo-stationary orbit and earth escape velocity. You dont need to go all that way :-)
The space station is orbiting in approximately 400
km, and it is much cheaper to go there.
Kristian
He, who dies with the most toys, wins
I'm glad that maglev technology is finally being applied to something worthwhile. I'm getting really tired of seeing all the maglev rail transportation projects that never go anywhere (figuratively and literally)... :
Kim Stanley Robinson wrote the RGB Mars book series, in which a space elevator was built on Mars. If I remember correctly (it's been a while since I read it), they modified the orbit of Deimos (or Phobos, I forget which) to geosynchronous, grabbed an asteroid or two from the asteroid belt, and had self-replicating robots build a factory there and start "spinning" diamond-filament threads.
By the time the asteroid got to Mars, most of the cable was already built, at which point it was anchored at a massive hold on the surface, and elevator cars were constructed to go up and down the elevator, using counterweights.
I believe that the problem of balancing it if you tried to "launch" something off the top of the platform was to simply give it a little push away, let it float off on it's own, and then use it's own engines to propel it.
Although it may seem a bit farfetched, I think that within the next decade, technology will allow us to realistically dream of doing this, although since we don't have nice-sized moons like Deimos or Phobos, we'd need to bring a bunch of asteroids in, which would make plenty of people on Earth rather anxious.
Still, it's a great theory, and perhaps some day we can get space elevators for cheap transportation into space.
Gawyn
Freedom of Speech?
Pardon my naivety but if a speed of over 7000 metres/sec is needed to achieve orbit, wouldn't the craft burn up?
And wouldn't it have to be going much faster than that off the launch track in order to be at 7000 m/s as it leaves the atmosphere?
It would be better to use the maglev to achieve the velocity necessary to cause a ramjet (or is it scram?) to ignite so as not to require the assistance of conventional jets, rockets and B52s to launch them.
Indeed, since O2 + 2H2 -> 2H2O an oxy-hydrogen motor doesn't look like harming the environment at all, unless it's the size of Madagascar. The winnage is in leaving the motor and its fuel supply Earthbound.
OTOH since launches don't happen continuously 24x7 the launcher could use solar/wind/tidal input and store it in superconducting accumulators for the next launch. These variable inputs are much more practical for powering rare events than for things like home heating or lighting. Win again.
And I made a mistake too.
OK, here is the correct formular:
a(t) = a(t)
v(t) = v0 + integrate(a(t))
v(t) = v0 + a(t)*t - Integrate (t * a'(t))
So the speed also increases because of decreasing gravity over time
s(t) = s0 + Integrate(v(t))
s(t) = s0 + v0 * t + a(t)* 1/2 * t^2 - Integrate(1/2*a'(t)*t^2) - Integrate ( Integrate (t * a'(t)))
This is more correct. But what it essentially means is that the higher you go with less gravity, the more easier it is to gain distance (=height)
Imagine a cable running from the top of a 50 km tower into geo-stationary Earth orbit. Travelling on the cable is made through electromagnetic propulsion. Nasa is considering a 50 years timeframe for the space elevator to become real.
Maybe I'll go in space after all.
Men are born ignorant, not stupid; they are made stupid by education. Bertrand Russel
My father is the John Cole quoted in the CNN article and it's his office that is managing the maglev (among a lot of much more interesting projects), so I am familiar with this particular project. No one at NASA want's to use maglev as the only method for putting anything into orbit, but rather as a launch assist for chemical rockets. You would be amazed at the weight savings just by accelerating a rocket to 500MPH before using onboard fuel. Also, another point missed by most is that while maglev has been around a while, one of the main problems has been power availablity. For an operational system, you will need 3-6 Megawatt's in 6 seconds. To solve that problem (they don't think they could get a large nuclear power plant just for this thing) they are thinking about using VERY large flywheels to slowly spin up and store the energy until launch. And funding is next to nill. The army was kind enough to donate a few model airplains for the test rig. I used to have some MPEG's of this, if I find the URL, I'll post them. For further perusing and some nice pics, try http://std.msfc.nasa.gov/ast/abstracts/0B_Cole.htm l
and http://std.msfc.nasa.gov/ast/index.html
John Cole Jr.