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...

Comments

Going to acceleration or height?

[AtariDatacenter]

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.)

Re:Going to acceleration or height?

[ender81b]

In theory they hope to use this to totally replace rocket launches as it would be

A. Safer
- all equipment on ground easy to maintain and in case of a failed launch or problem the rail would still result in a partial launch - meaning the pilot could presumably guide the plane/wahtever to a landing.
- No need to carry volatile chemicals

B. Cheaper since, once agian, everything is on the ground - no need for throwaway boosters, etc Indeed once you pay for the construction all that is left is electricity and maintence.

C. The plan isn't to accelerate them vertically as the G forces would kill a man to obtain earth orbit you have to have a speed of (I think) 25 Km/Sec which would, in a vertical launch scenario of say a 1000 meter tower, result in way over the 9-10 G's a human can survie. Instead they will be launched off of a gradually ascending slope spanning a couple of kilometers.

However, and this is a big iffy, in all honesty this technology will go nowhere without superconducting materials to use in the rail. Without these existing, or any future, non-superconducting material cannot hope to maintain the power output/magnetic field necassary to propel an object to Earth Orbit or Near Earth Orbit (NEO).

New ICBM delivery method?

[flacco]

Would this result in lighter ICBM's with no vulnerable, sluggish launch phase and no heat signature during launch?

Though I guess you'd have a hell of an "electro-magnetic signature".

Re:Used up in the cost to get the electricity, tho

[King Of Chat]

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).

Re:Formulars are flawed

[germanbirdman]

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)

I prefer the space elevator

[clarkie.mg]

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.