crazy (?) space launch idea, shotput sling.

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hanelyp
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Joined: Fri Oct 26, 2007 8:50 pm

crazy (?) space launch idea, shotput sling.

Post by hanelyp »

Getting back to technical discussions...

The concept flight profile:

Launcher takes off on rocket power, and shotputs to well above sensible atmosphere.

Between top of sensible atmosphere and top of flight arc the launcher spins up, end over end, and deploys the payload at the end of a sling. Ideally the payload is accelerated to orbital velocity.

At top of flight arc the payload is released into orbit.

The launched reels in the cable, de-spins, reenters, and returns to launch site.

The one gotcha I'm seeing is how to reel out the necessary length of cable in the limited time.
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GIThruster
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Re: crazy (?) space launch idea, shotput sling.

Post by GIThruster »

The trouble I see is with what might be meant by ". . .the launcher spins up, end over end, and deploys the payload at the end of a sling."

What do you mean by this or in what way does the launcher spin up? Where does that energy come from? What is one pushing off?

While you could do this, spin up a moment arm or some such and then release a projectile from it, you would not be gaining any significant advantage over applying that power directly to the projectile. The "launcher" in this case is just an intermediary momentum transfer mechanism, and once it lauches, you would presumably need to rotate it back down to near zero rotation and load the next projectile. In winding it down you are throwing away a great deal of energy, so there goes your efficiency.

Now contrast this to the lunar sling concept for throwing projectiles into lunar orbit from the lunar surface. That's down in a gravity well and you can push off the Moon, so the lunar sling is an extremely attractive proposition based upon efficiency, and it is practical since you can store energy in the sling. You still lose the energy the sling has just after release, but this is okay because of the other advantages. Power it with solar, and direct the solar into the sling, while laden with projectile. Spin it up slowly with virtually no resistance/frictional losses since there's no atmosphere. (This is not practical on the Earth.) This is a very efficient energy storage system as well as a system for lofting lunar regolith, though one supposes you want to refine it into whatevr you're going to use it for before launching it. Probably Al stock.
"Courage is not just a virtue, but the form of every virtue at the testing point." C. S. Lewis

hanelyp
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Joined: Fri Oct 26, 2007 8:50 pm

Re: crazy (?) space launch idea, shotput sling.

Post by hanelyp »

What do you mean by this or in what way does the launcher spin up? Where does that energy come from? What is one pushing off?
Thrusters or reaction wheels.

I'm thinking the launcher is several times more massive than the payload, so the payload gets far more energy that the launcher from the spin-up. The otherwise inert mass of the launcher acts as reaction mass for delivering the payload into orbit. The cable lets the payload be accelerated over a longer distance, far more gently than a gun the length of the launcher.
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KitemanSA
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Location: OlyPen WA

Re: crazy (?) space launch idea, shotput sling.

Post by KitemanSA »

Read up on HASTOL or KiteLauncher. Both do what you want realistically.

Diogenes
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Joined: Mon Jun 15, 2009 3:33 pm

Re: crazy (?) space launch idea, shotput sling.

Post by Diogenes »

Crazy space ideas. Anyone seen any of the Avenger movies? See that giant helo carrier?


Image



No, not that, but similar.


How about four (more or less) blimp/dirigibles in a similar configuration anchored to a large frame. The thing simply pulls rockets to it's operating height with a winch. We may not have the technology to make a space elevator cable, but we D@mned sure have it sufficient to make a powerful but light weight winch line.



The spacing between the dirigible/blimp float devices can be made sufficient that the rocket blast poses no serious risk of damage to them.



You get rid of most of the atmosphere and most of the fuel load requirement. Perhaps you can get it up to 100K?


Just an idea.
‘What all the wise men promised has not happened, and what all the damned fools said would happen has come to pass.’
— Lord Melbourne —

KitemanSA
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Joined: Sun Sep 28, 2008 3:05 pm
Location: OlyPen WA

Re: crazy (?) space launch idea, shotput sling.

Post by KitemanSA »

Launch Loop
KITE Launcher
HASTOL

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