Alternative Orbit?

[calbiterol]

I've long been pondering the effectiveness of an alternative system to rockets as a means to get into Earth Orbit. Escape Velocity is generally defined as about 9.0 kilometres per second and is the velocity at which an object will escape the pull of Earth's gravity and obtain orbit.

 

So here's my alternative system. It uses a massive gravitational and magnetic accellerator to throw something into orbit. It would work like this - you have a *VERY* long U-shaped tube that is wide enough to fit a module/projectile within it (Just like this picture).

Wound around this tube are many, many electromagnets. Past the electromagnets are fixed magnets. The module (which is dimagnetic) is first situated at the top of one side of this U-tube. The fixed magnets should keep it floating in the center of the tube, not touching any of the walls. The module is then released, and gravity pulls it down. In addition to gravity's pull, each electromagnet surrounding the tube is "switched on" when the dimagnetic module passes the center of that electromagnet. These electromagnets are supplied power by capacitor banks, with one capacitor bank for each electromagnet. When the module gets to the bend in the U, it is gradually pushed back upwards and towards the sky - this time, however, the magnets are doing a lot more work, accelerating the module even further, despite the fact that it is working against gravity. Could something like this be used to catapult something into orbit? The power costs would be massive, yes, but I thought about that, too. But first, the structural engineering side of it. Something like that would have to be massive. To accomodate for the structural pressures of building something so tall, you could either A, submerge it in water, B, bury it in Antarctic ice, or C, bury it underground. Either way, the primary ways of drawing power would be geothermal and solar. Clean and effective. Maybe the whole thing could be made into a vaccuum chamber, ridding the tunnel of air friction and preventing the devastating effects of a sonic boom. The only problem then is, how do you get the module out of the tube if the tube is sealed? Maybe what could be done is to give the module a pretty good seal with the sides of the tube (without touching the sides), and after dropping the module, open a hatch behind it - letting air pressure accellerate the module even more. Then, when it gets to the top of the other side of the U, either a hatch opens (more like... explodes) to let it out (but timing would be near impossible), or it punches through glass, or... Aha, an even more effective way - the seal is simply blown up with explosives, reducing loss of momentum and allowing it to wait 'till last minute to break the seal. Anyways, what do you think?

[Cap'n Refsmmat]

Wouldn't the magnets destroy any electrical equipment inside the spacecraft?

 

 

Also, you have to account for atmospheric friction, so you would have to launch it much faster as it goes through the thickest part of the atmosphere. You would need heat shields both ways.

[calbiterol]

Yes, the magnets would probably destroy most electronic equipment. But first, the module wouldn't need any to function. If you were concerned about not making it into orbit, then you could always have a person onboard there to deploy a parachute in an analog way, without electronics.

 

As far as biological cargo (in other words, humans) and other non-magnetically-sensitive materials, it'd be a dirt-cheap (comparatively, even including startup costs) way to get into orbit.

 

As far as a heat shield goes, it might not be needed on the way down. First, you could feather it like SpaceShipOne. Or, alternatively, you could either reassemble the module in orbit for a descent, or you could go down facing the same way as when you came up.

[Cap'n Refsmmat]

What's the point of a spacecraft if it can't have any electronics? Humans can't survive without the life-support equipment. Computers are used to control descent so people don't burn up. There can be no sensors or radar to help guide them into orbit and then re-enter.

[ecoli]

It's actually a pretty good idea...and NASA agrees with you, though they're doing it in a better way. (no offense intended...it's what NASA scientists are paid to do)

 

http://liftoff.msfc.nasa.gov/News/1999/News-MagLev.asp

http://liftoff.msfc.nasa.gov/News/2000/News-MagLev.asp

[calbiterol]

What's the point of a spacecraft if it can't have any electronics? Humans can't survive without the life-support equipment. Computers are used to control descent so people don't burn up. There can be no sensors or radar to help guide them into orbit and then re-enter.

 

Not true. Not ALL electronics are fried by magnetic fields, just most. I also think I heard something about magnetic sheilding somewhere.

 

What's the point? It's dirt cheap. Raw materials won't get fried. Getting into orbit can be done manually. If computer control really is necessary on the way down, then manufacture it up in the sky - or, alternatively, salvage the heat shield and just let the module burn up in the atmosphere. If the object is to get to a colony, then that's that. Otherwise, you'd have to construct a descent module.

 

This isn't something that could be made tomorrow. By the time it could be ready, there most likely would be a way to manufacture electronic components in space. If it really is an issue, then send up electronics in a cheap conventional rocket, but use something like this as a heavy lifter. This kind of thing would really pave the way for space-based manufacture. Why spend many millions of dollars on sending something up in one piece when you could send it up in pieces and manufacture it in space for almost nothing?

 

 

 

[Edit: NOOOOOOOOOOOOOOOOOOOOOOOOO!!!! I've been beaten to the punch line AGAIN! (Continues slow-motion yelling) NOOOOOOOO!

 

It's actually a pretty good idea...and NASA agrees with you, though they're doing it in a better way[/i']. (no offense intended...it's what NASA scientists are paid to do)

 

Here's where we differ. I would say that my way is better, because it uses NO rocket fuel. It's got its disadvantages, yeah, but it's almost free (only costs I could see would be maintenance, etc) and it's simple. Simple is often best.

 

No offense taken.

[Mokele]

I actually did some work with NASA on that project, back when I was an aerospace major. Very cool stuff.

 

I would say that my way is better, because it uses NO rocket fuel.

 

Except for the problems of breaking the sound barrier that close to the ground. I'm not an expert in that field, but I'm told the results are Not Good with capital letters.

 

Plus, remember, drag force is dependent on air density and speed. Moving very, very fast though sea-level (or nearly so) air costs a *lot* more energy. In fact, so much that I suspect any benefits you'd get from your system would be lost. Best bet would be to calculate exactly what speed would be optimal for release and going to simple rocket propulsion.

 

but it's almost free (only costs I could see would be maintenance, etc) and it's simple. Simple is often best.

 

Free? Where does the power for the electromagnets come from?

 

Oh, FYI, if you just make it a flat, outdoor track, not only will it be cheaper, but you can use Halbach arrays (permanent magnet arrays that require no outside power to produce lift, just velocity (trailing eddy currents)) to lift the ship and keep it on the track, reducing EMs to just propulsion. That's actually the part I was looking into.

 

Mokele

[calbiterol]

 

I actually did some work with NASA on that project, back when I was an aerospace major. Very cool stuff.

 

 

 

Quote:

I would say that my way is better, because it uses NO rocket fuel.

 

 

Except for the problems of breaking the sound barrier that close to the ground. I'm not an expert in that field, but I'm told the results are Not Good with capital letters.

Yep. I believe that that's because of the sonic boom it produces. That's why I was considering a vaccuum chamber as the tube. There's also a fair amount of research going into reducing/eliminating the sonic boom behind supersonic airplanes. The same principal could be applied here.

 

Plus, remember, drag force is dependent on air density and speed. Moving very, very fast though sea-level (or nearly so) air costs a *lot* more energy. In fact, so much that I suspect any benefits you'd get from your system would be lost. Best bet would be to calculate exactly what speed would be optimal for release and going to simple rocket propulsion.

 

Or, it could be built into a mountain.

 

Quote:

but it's almost free (only costs I could see would be maintenance, etc) and it's simple. Simple is often best.

 

 

Free? Where does the power for the electromagnets come from?

Like I said originally, it would be completely self-sufficient, running off of geothermal and solar power to supply/recharge the capacitor banks.

Oh, FYI, if you just make it a flat, outdoor track, not only will it be cheaper, but you can use Halbach arrays (permanent magnet arrays that require no outside power to produce lift, just velocity (trailing eddy currents)) to lift the ship and keep it on the track, reducing EMs to just propulsion. That's actually the part I was looking into.

 

Mokele

 

An intriguing possibility. Perhaps a hybrid of the two systems would be best.

[calbiterol]

This is kinda along the same lines as my magnetic orbit thingy. So there's talk of building a space elevator from the surface of the moon to Earth orbit. There's an article about it here.

 

First, what if an extremely high-speed magnetic train were run from Earth orbit to the moon? Second, could some sort of magnetically-propelled, extremely high-speed launcher (like the one I described, or the one NASA was working on) be used to give things a head start on other planets?

 

Alternatively, for both achieving orbit and interplanetary transit, what about a massive railgun?

[JohnB]

it's what NASA scientists are paid to do

What, watch old George Pal movies?

 

Their representation looks amazingly like the ship from "When Worlds Collide." Come to think of it, so is their launch system.

[ctc7752]

How about nuclear? Simple, yet effective.