Lighter than Air Suborbital Craft

Terraformer · 2007-11-18 08:20:07

I didn't know which forum this topic belonged so I stuck it here.

Instead of using rockets to get a suborbital craft up, why don't Virgin just use a Blimp. It would be cheaper and there wouldn't be a load of Gs to contend with during acceleration.

There would be a helium/hydrogen blimp with a control car in the front. At the back a suborbital craft would be attached. The pilot of the blimp would take the craft up to the edge of space and release the clamps holding the suborbital shuttle whish would then gide back to Earth, using no fuel. The blimp would then come down, a new shuttle would be loaded, and it would go up again.

Are there any flaws in my thinking?

JoshNH4H · 2007-11-18 13:02:04

blimps can't get anywhere near suborbit, but bringing a suborbital craft a high as a blimp can go and then launching from there has already been suggested. The problem is that blimps use the air to rise, and there is, by definition, no air in space.

Terraformer · 2007-11-18 14:10:16

Actually, the atmosphere doesn't end there. It's called the edge of space because there needed to be somewhere to call the edge of space. Even if there was no atmosphere there the balloon would float on top. As it is there is an atmosphere there. A balloon using heated hydrogen would do it easily. A mix of 50% helium 50% hydrogen is a good trade off. Heat it to ncrease it's lightness. If the small control car detatched and a parachute came out there would be no safety issue. If the balloon set on fire (unlikely due to lack of oxygen) or popped the Balloon pilot would unclamp the shuttle and detach from the balloon wreck.

samy · 2007-11-24 23:03:02

No, I'm sorry. In a vacuum (or near-vacuum), a balloon will fall if it is in a gravitational field. Its lift comes from displacing air. If there is no (or very little) air to displace, it won't have lift.

Buoyancy B needs to be greater than weight G, in order for the balloon to rise. In a vacuum or near-vacuum there is no or trivial buoyancy.

Terraformer · 2007-11-25 07:15:20

There is air up there. The bulk of the atmosphere is below that point but the craft would just sink down until it is practically on top of the bulk of the atmophere. That's still around sixty km up. A modified version could have the suborbital craft launch, fire its rockets to get higher, thn glide back. But it would still use less fuel than Virgin Galactics SpaceShipTwos.

Go higher and antimatter might become a problem.

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#1 2007-11-18 08:20:07

Re: Lighter than Air Suborbital Craft

#2 2007-11-18 13:02:04

Re: Lighter than Air Suborbital Craft

#3 2007-11-18 14:10:16

Re: Lighter than Air Suborbital Craft

#4 2007-11-24 23:03:02

Re: Lighter than Air Suborbital Craft

#5 2007-11-25 07:15:20

Re: Lighter than Air Suborbital Craft

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