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One of the big costs in getting a conventional spaceship off the ground is getting it to lift its own fuel.
My invention reverses this problem into an advantage.
One trick used to bypass the problem is to lift a conventional rocket using a more efficient system for the first few miles.
Examples
of this have been the X-Plane and Balloon assisted launches: See Links
But BOTH these techniques are still hopelessly inefficient because of the way they use their lift vehicles.
Another solution is not to take the fuel with you: See Links
So the next step is that you use your lift vehicle AS they fuel for the next launch stage.
Take a massive hydrogen balloon as the initial lift vehicle.
Current technology gets this up to 100,000 ft (30Km), Note that at this point we are above the Troposphere (10Km) and so the later stages are much less effected by atmospheric drag.
The next trick involves oxygenating the hydrogen and then the use of shaped charge technology to perform a controlled explosion of this lift balloon. The space bound package is placed at the top centre of the balloon and the shaped explosion is focused to act through this point, pushing the package upwards.
Now the HARP cannon could achieve low orbit at 180Km, firing through the troposphere, so this focused explosion should easily project the package into low earth orbit.
Firing from above the Troposphere and most of the Stratosphere we might expect much greater efficiencies and there is nothing to prevent the package containing conventional rocket systems to lift it even higher.
Two points:
1 -There might be a tiny bit of work to do on creating the shaped charge explosion and making tough packages but these seem trivial details.
2- I dont think the first launch will be manned.
Ballon Lift
http://www.space.co...oonarch_012103.html
[RattyBunyip, Jan 22 2009]
Lift aircraft
http://en.wikipedia.org/wiki/SpaceShipOne
[RattyBunyip, Jan 22 2009]
Big gun system
http://en.wikipedia.org/wiki/Project_HARP
[RattyBunyip, Jan 22 2009]
Your mission, should you choose to accept it.
N-Prize
[coprocephalous, Jan 22 2009]
Project Orion
http://en.wikipedia...nuclear_propulsion)
Bomb goes boom, ship goes up. [MechE, Jan 22 2009]
NASA Antarctica Balloon
http://post.space.g...-successfully-tests
1ton payload, 110,000ft Altitude [RattyBunyip, Jan 22 2009]
First incarnation of this concept on the HB
into_20orbit
[bungston, Jan 23 2009]
Second incarnation of this idea on the HB
LTA_20_2b_20rocket_20for_20SSTO
[bungston, Jan 23 2009]
Another HB rocket ballon hybrid, now with guns.
Rockeloonannon
[bungston, Jan 23 2009]
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But can you do it for $999.99 or less? |
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I'm not certain how well the munroe effect will work with a gaseous low explosive. The effect is highly dependent on shaping the explosive material, and I don't know how well shaping the envelope would work. At the very least, this concept is very different from HARP, but somewhat similar to another:
For tough pulse propulsion lift vehicles look up Project Orion. Since you'd only have a limited pulse count, you'd probably want to drop the pusher plate after the pulse and have it return to earth, but the concept is feasible. Given the mass involved, and if you could work out the details, you might want to vent the hydrogen behind the ship prior to detonation. Less focus and less total force each time, but it would allow for more than one pulse. |
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//Using hydrogen to reach the moon, you need 10,000l of gas. This is can be contained in a sphere 32m in diameter, which could probably lift a small mass.// A 32m sphere would hold a whole lot more than 10 m^3 of hydrogen. |
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Thanks for the n-prize ref. Great idea. I still dont know if you could do it. The Antarctica balloons are pretty hi tech materials. Maybe if you built in from 'recycled' council bin bags rather than "special lightweight polyethylene film" you might get somewhere :-) |
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Ok so I think it is better to pump the gas down to a rocket and burn it normally --- so there is still a requirement to carry enough oxygen burn with the fuel. Not sure it will work but I am picturing a rocket with a big balloon on top that gradually get smaller as its contents are burnt as fuel... |
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//But can you do it for $999.99 or less?// That's £999.99 or
less, actually... (link) |
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Have you seen the exchange rate [MB]? |
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Yes, but the exchange rate is pegged at the best rate
obtained during the first 9 months of the competition, so US
teams are on almost $2 to the £. |
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The problem is that the gas wouldn't explode, it would just burn. The key to efficient thrust is pressure. The balloon would either be low or no pressure, either way you miss a key piece of the puzzle. Imagine running a car on 2:1 compression and there you'd still be better off than this. I don't know where the other annos are getting their numbers but without pressurization you'd better multiply the amount needed by thousands. The shuttle is burning their H2/O2 at thousands of PSI, this would burn it at 1 or 2 PSI. Sorry, bad science (-). |
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I was always curious, why are some NASA bases at sealevels, why don't they put on the top of the mountains?? |
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Everest is at 8km, and low orbit is 1-200km, so you're not
saving a lot. That said, 8km gets you above a lot of
atmosphere. But, that said, it also makes it very difficult to
work at that altitude. |
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[QED] It's a low explosive, definitely, but so's the fuel in an FAE. If thoroughly mixed with air prior to ignition, it should burn quite violently. It is going to be pulse propulsion and it would be less effective in the lower pressure upper atmosphere, with less air to transmit the shockwave. I would think, however, it should still provide some kick. |
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[xhuntay] Location. Being equatorial is more valuable than being high. Seeing as the US is rather short on equatorial or near equatorial mountains, you have to take what you can get. |
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Yes, some kick, just not a kick that will get you to orbit. |
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And I always wanted to build a ram up Kilamenjaro, but getting the rest of the resources there would be annoying. |
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As a stand alone, probably not, I was thinking more of an
assist prior to rocket ignition. Especially if used piecemeal
for multiple pulses just prior to exiting the upper
atmosphere.
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Not quite the original idea, I realize, but possibly a viable
evolution. |
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Some magic words are 'shaped charge' and 'oxygenating the hydrogen '. |
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The point of shaping the explosion - probably with a detonator array on the skin of the balloon -is that the initial shock waves contain and pressurise the gases for the later explosions - more force/pressure/bang for your buck.
I did realise that the air is a bit thin up there so I thought lugging along some oxygen (to get maximum efficiency) would be a small price to pay. How you actually go 'oxygenating the hydrogen ' (mixing the two gases) is minor engineering detail. The current (small) high altitude balloons are carrying a ton or so payload for weeks so I am sure a few LOX bottles aren’t a problem. :-) |
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How much kick? well how big a balloon do you want? For this sort of task the balloons could be HUGE. 100m diameter? 1Km diameter? 2Km?
Its not like a rocket where adding power is a problem because you have to lift more fuel. |
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I also have no objection to stealing the current US balloon lift idea and putting rockets on the projectile, so that once the momentum it gets from the balloon explosion dies away it can kick in its own power. |
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Welcome Bunyip. Obviously you have come to the right place to talk about rockoons. You might consider moving this idea to the space launch category so it can join its siblings. |
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Hawaii has big mountains and is close to the equator. American Samoa is a little closer but lower. |
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/better to pump the gas down to a rocket and burn it normally/
One could have an adjunt to a rockoon like this to harness the expansion of the hydrogen at higher altitude. The balloon could expand to some degree, but pressurized hydrogen is tougher to conatin and less lifty. There could be a valve leading to a combustion chamber. If hydrogen could bleed off from the balloon to maintain an internal hydrogen pressure equal to the external atmosphere, the lift would remain constant. Bled hydrogen could be flamed off. Now that gives me an idea... |
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I did think about Hawaii, and I suspect the major objections to locating the US launch facility there were threefold. 1) Lava 2) WWII 3) USSR.
The first would make it difficult to build a permanent base on the big Island, but some of the others would still be possible.
The second would have been fresh in the memory when the space program was starting up.
Proximity to the third would have likewise have been a major concern.
The difficulty of transporting equipment there might also have been a consideration.
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None of which completely rules it out now for a new facility. |
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Why not use the balloon to lift a conventional H/O2 rocket, only without the H tank. Then just pump the H direct from the balloon when you ignite the rocket. |
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Granted, the rocket will have to negotiate its way around the balloon and there will still be a little drag on the balloon even in the thin atmosphere, and then there's the slight issue of having your H supply sitting behind the exhaust flame in a very thin bag, but I'm sure these details can be overcome with sufficient optimism. |
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//these details can be overcome with sufficient optimism//
[marked-for-tagline] |
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How about using an even larger array of balloons to lift the entire launch pad to a high altitude? |
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It's not enough just to *get* to space. You also
have to be moving at umpty up thousand miles per
hour laterally. Otherwise, you'll just fall back
down and make a mess. |
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[bungston] - ta - silly me to think a space ship was a vehicle :-) |
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[colorclocks] Speed is key, agreed, but its MUCH easier to get speed once you are high up in the atmosphere. Less drag, more velocity. The point of all this is that if the controlled explosion itself doesnt get you far enough, then you get to start using your conventional technology from a lot higher up. Thats a big advantage. |
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