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# Hydrogen balloon plus Gauss gun

A rather feeble thought on the N Prize
 (+6) [vote for, against]

I am nowhere near even being able to think coherently about any of this, but here it is.

Take a weather balloon and put hydrogen in it. Attach an oxygen cylinder but seal it thoroughly. Put some kind of ballast at the bottom and a small, lighter Gauss gun at the top, in a nose cone for streamlining. Let it go.

When the balloon reaches the height where it's about to burst, a pressure gauge releases the hydrogen and the oxygen downwards and ignites them, converting the balloon into a rudimentary rocket (is that a rockoon? I don't know). When the fuel runs out, the payload at the top can detect that it has stopped accelerating, and it would be somewhat above the maximum height of a hydrogen balloon, particularly because streamlining has eased acceleration.

The Gauss gun is balanced by a gyroscope. It also has a photocell, which turns off a switch when it detects the sun - the right angle for an orbital trajectory, depending on the time of day. Energy is stored in a capacitor to operate the gun.

The final satellite is a steel object of the appropriate weight containing another gyroscope, a digital camera, a timer and some flash memory.

When the payload stops accelerating, the gun lines up with the sun and discharges its satellite at the appropriate angle, which is determined by the time of day. This accelerates the satellite further.

Once it reaches orbit, which can be determined by timing, the satellite, stabilised by the gyroscope, takes a series of photographs once every ninety minutes, for a hundred images. After about a week, it uses a laser to beam the images as a series of JPEGS downwards towards the ground, repeatedly and without pausing.

I dunno, it's just something i've thrown together and there's no maths or engineering in it because i'm a simple arts graduate, but there it is. Now tell me what's wrong with it.

 — nineteenthly, Jun 24 2008

Rockeloonannon Rockeloonannon
[MisterQED, Jun 25 2008]

JP Aerospace - Ballooning to orbit http://www.jpaerospace.com/
[MisterQED, Jun 30 2008]

 we.e.e.e.e.ll - I like the thought process behind it. Which is another way of saying there are some flaws. For one, I'm not sure that your oxygen/hydrogen exploding balloon is going to be a very effective rocket. You might be better off just leaving out the oxygen cylinder and getting extra altitude from the balloon. For another, I'm not sure that a satellite with a gyro is going to survive the sorts of accelerations afforded by a railgun - I think the gyros will be mushed.

On the other hand, since when I have I known what I'm talking about?
 — MaxwellBuchanan, Jun 24 2008

I like the part where all the hydrogen balloons are fuel for a rocket... though no clue where the railgun's gonna fit in.
 — FlyingToaster, Jun 24 2008

 Hmmm. It would be fun to try.

If the Oxygen tanks base was the rockets venturi nozzel, and a shaft ran vertically from the tank to the top of the ballon, (to keep some semblance of aerodynamics as the Hydrogen is expelled), would there even be a way to vent enough of the Hydrogen to sustain an HHO mix?
 — 2 fries shy of a happy meal, Jun 25 2008

Balloon, then rocket then a railgun... a railgun is like a cannon.. so this sounds like a rockeloonannon.
 — MisterQED, Jun 25 2008

 Rock Rock, Rockeloonannon

 I love Rockoons, but I think your added height is going to be not much. Plus no oxygen canister. Better to fire the railgun from atop the balloon, which might be reasonably steady. When the rockoon slows down stuff is going to be flying all over the place.

If you had a solar panel to charge a capacitor, you might get more than one shot out of your railgun.
 — bungston, Jun 25 2008

 I have been thinking along similar launching lines (not so much with the rocket bit though). i.e "cannoon", but you want to try and recover the launch vehicle to mitigate costs. So blowing it up is not an option.

I think on that budget, we all are thinking launch from altitude. I would go with a Gauss gun, instead of the rail gun version. The problem is tracking the orbit. Cameras, SSD, gyroscopes and lasers, circuitry, power, are bound to weigh in a little over the 19 grams mark. The orbiting mass is going to have to be very thin to get a large visible surface. Or loud in the RF range. SETI has big ears.
 — 4whom, Jun 25 2008

 OK, so what if the balloon contains a perfect mixture of oxygen and hydrogen, and this is at almost at 1 bar pressure at altitude? The mixture could be released through a nozzle for thrust, once the maximum height for buoyancy has been reached. The balloon ought to reach a good velocity since air friction is very low. Also, as velocity increased, wouldn't the balloon be compressed by the pressure on the lead face, and the force from the nozzle, thereby increasing the internal pressure of the Hydrogen and Oxygen mix?

This would give an easy way to lift huge quantities of hydrogen and oxygen. But I think it hinges on the density of the Hydrogen and Oxygen mix. Can anyone comment on that?
 — Ling, Jun 25 2008

 OK, edited to replace "railgun" with Gauss gun - no moving parts. What if the satellite is a piece of steel foil which unfolds to form a reflective sail once in orbit and i forget about the camera? I would say Mylar or gold leaf, but i would've thought it would need to be ferromagnetic for the gun to accelerate it properly. I also realise now that the photocell/lining up business isn't necessary because there could just be a tube pointing in the right direction. Still thinking about the rest: thanks.

 Right: still not much thought on how to accommodate some of these ideas, but i think this might work:

 The balloon is rocket-shaped, with fins and a nosecone, but also elastic. The Gauss gun forms a central column at whose bottom sits the payload. Since it's streamlined, it will rise quite fast, and will overshoot the height it would reach if it were a balloon. It contains a good mix of oxygen and hydrogen. This is ignited once the acceleration ceases, so the fuel pushes the balloon higher. This would presumably need to be done in some kind of ignition chamber isolated from the rest of the reservoir. When the acceleration slows again, it activates the coil gun, which shoots the ferrous payload out of the top at some velocity, God knows what, sorry. You therefore have the velocity of the balloon plus that of the fuelled "rocket" plus that of the coilgun. It would need to be at a particular angle off the vertical at the final stage and i don't know how this could be done unless it was somehow by piezoelectric bending like in some other idea on here, can't remember which one.

Then, the satellite reaches orbit and unfurls into a large, reflective sail whose mass is around nineteen grammes. How does it unfurl? I don't know. The sail can then be detected by telescope, or possibly by bouncing a laser off it if it can be found (which it can't, presumably).
 — nineteenthly, Jun 25 2008

 I worry about the Tom Sawyer aspects of the coilgun / railgun etc - very cool but unproven and fussy technology. Would it not be simpler to carry up a standard solid fuel rocket like the hobbyists use?

Also I would love to see some math on rockoons. Or maths if you are a subject of the Queen. I suspect they would need a frame to keep the thrust nozzle from punching up through the rest of the balloon.
 — bungston, Jun 25 2008

 I just don't know, do i? A frame sounds sensible and doable. Would a coilgun be lighter than a solid fuel rocket?

 I think i should stop saying "i don't know" and go and do some research.

...aaand Googling for coil gun projectile velocity brings me straight back to the HB. No wonder people get stuck here.
 — nineteenthly, Jun 25 2008

 // No wonder people get stuck here //

 Stay awhile ....... stay - FOREVER !

 MUHWHAHAHAHAHAHAAAAA !

Ahem.
 — 8th of 7, Jun 25 2008

Well, i only ended up here in the first place, five years ago or whenever it was, because i started searching for various things and repeatedly found links to this place. It's about as easy to leave it as it is to go into orbit.
 — nineteenthly, Jun 26 2008

 "And the end of all our searching shall be to return to the place where we started and know it for the first time."

- T.S. Eliot
 — csea, Jun 27 2008

//ignites them, converting the balloon into a rudimentary rocket//
Actually, the balloon is converted into a burning replica of the Graf Zeppelin, and the oxygen cylinder is converted into a rudimentary bomb.
 — ldischler, Jun 30 2008

I don't know. I was dubious, but look at the JP Aerospace link. If you did a big enough balloon, this might work, not the firing a gyro out a railgun part, but the other part. They did it with propellors and then a second stage balloon for final acension, but the idea is not as crazy as I originally thought. Obviously you'd have to carry a LOT more hydrogen than oxygen and you'd have to run some kind of turbopump to pressurize the gases that you are pulling from the balloon before they would work in a rocket, but there is some novelty here.
 — MisterQED, Jun 30 2008

 //Actually, the balloon is converted into a burning replica of the Graf Zeppelin, and the oxygen cylinder is converted into a rudimentary bomb//

I changed my mind about that - probably should've put it in the main body of the idea rather than the annotations. What i decided was that there should be nozzles and a combustion chamber below the balloon rather than the gas inside the balloon being ignited. I was thinking of a mixture, but actually the balloon should probably contain two reservoirs, one of each gas, then ignite them after they pass through a series of valves in tubes, because it reduces the risk of backing up and insulates the reservoirs.
 — nineteenthly, Jun 30 2008

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