16 January 2010

Ocean Space Launch From the Barrel of a Gun

How to Shoot Stuff into Space

The gun combusts natural gas in a heat exchanger within a
chamber of hydrogen gas, heating the hydrogen to 2,600˚F and causing a 500 percent increase in pressure.

Operators open the valve, and the hot, pressurized hydrogen quickly expands down the tube, pushing the payload forward.

After speeding down the 3,300-foot-long barrel, the projectile shoots out of the gun at 13,000 mph. An iris at the end of the gun closes, capturing the hydrogen gas to use again. _Popsci

Google Tech Talks Video (via Brian Wang)

John Hunter's mid-ocean space launch gun is powered by hydrogen and natural gas, and hopes to launch payload into orbit for a mere $250 a pound.
Building colossal guns has been Hunter’s pet project since 1992, when, while a physicist at Lawrence Livermore National Laboratory, he first fired a 425-foot gun he built to test-launch hypersonic engines. Its methane-driven piston compressed hydrogen gas, which then expanded up the barrel to shoot a projectile. Mechanical firing can fail, however, so when Hunter’s company, Quicklaunch, released its plans last fall, it swapped the piston for a combustor that burns natural gas. Heat the hydrogen in a confined space and it should build up enough pressure to send a half-ton payload into the sky at 13,000 mph.

Hunter wants to operate the gun, the “Quicklauncher,” in the ocean near the equator, where the Earth’s fast rotation will help slingshot objects into space. A floating cannon—dipping 1,600 feet below sea level and steadied by a ballast system—would let operators swivel it for different orbits. Next month, Hunter will test a functional, 10-foot prototype in a water tank. He says a full-size launcher could be ready in seven years, provided the company can round up the $500 million. Despite the upfront cost, Hunter says he has drawn interest from investors because his reusable gun saves so much cash in the long haul. Just don’t ever expect a ride in the thing: The gun produces 5,000 Gs, so it’s only for fuel tanks and ruggedized satellites. “A person shot out of it would probably get compressed to half their size,” Hunter says. “It’d be over real quick.” _Popsci_via_Scienceblips

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Anonymous Anonymous said...

The idea of having the gun built under the sea is really clever. Sure you could drill a tunnel but the water concept means you can change the angle at will and building something like this above ground would be impractical. This approach could make the plan workable far sooner.

I wonder if there is a potential for something intermediate between a ten foot prototype and a full scale device shooting half-ton payloads. Something that might prove useful for lifting smaller payloads to orbit while proving the concept.

Saturday, 16 January, 2010  
Blogger al fin said...

Very good question, Baron.

There is also the question of materials strong enough to resist collapse or warpage over such a long length, yet light enough to be easily floated and manipulated.

Expanding gases can travel rather quickly if motivated, but maintaining pressure within the barrel at the same time may be tricky. Firearms and artillery are made of rather thick, strong metals that can be quite heavy. What will the undersea space launch gun barrels be made of?

Saturday, 16 January, 2010  
Blogger al fin said...

Never mind.

Watch the video that I found over at NextBigFuture. It answers most of my questions.

Saturday, 16 January, 2010  
Blogger Loren said...

Look up Gerard Bull and project HARP. This idea isn't new, though the particular process is.

Sunday, 17 January, 2010  
Blogger Bruce Hall said...

Not sure if you ran across these:




Many others, of course.

Sunday, 17 January, 2010  
Anonymous Anonymous said...

I went over to the NBF post and read BW's article on the subject and I read the PS article too. In the NBF post Wang has a graphic showing a four stage commercialization of this:

1. prototype
2. 2 lb launcher
3. 100 lb launcher
4. 1,000 lb launcher

If the seacannon is only going to be used to ferry materials, fuel, water and canned food then the 100 lb model should be sufficient without the need to build a bigger gun. If the designer of this could start at stage one and skip to stage three and commercialize there then he would be able to achieve profitability faster.

The only customer I can see that would have the need for a steady stream of supplies to low earth orbit would be NASA. I wonder what Richard Branson's space craft would cost on a per pound basis.

Sunday, 17 January, 2010  
Blogger al fin said...

Bruce and Loren: Watch the Google Tech video provided, and you'll see why the sea cannon blows away chemical rockets, electromagnetic launch (slingatron etc), and gunpowder launch (Bull's HARP).

Ron: I agree that profitability could be achieved well before the final version of the device, if it works as advertised.

If this device can be made to work as planned, it will change the complexion of space enterprise very quickly.

With cheap access to space, only a world-scale government with total control over energy use (like the UN and Mr. Obama would like to put in place) could stop humans from breaking out of the cradle - cum - comfy prison called Earth.

Sunday, 17 January, 2010  
Blogger Loren said...

I was simply pointing out how old the idea is. I'm watching the vid now, but I'm sure there's numerous advantages to his system.

Guns are good for dense, hard cargoes. Assuming you can assemble complex stuff in orbit, you can get just about anything up with this--your trusses and shells will be in pieces though. Cans full of hull plates and truss spars would be shot up, and rendezvous with an assembler which would build most of the final product. This would really be simply taking the modular approach to its logical conclusion.

Sunday, 17 January, 2010  
Blogger al fin said...

I agree, Loren. Use the "slam, bam, thanky ma'am" approach to launch fuel and densely packed hardware. People will have to be treated more delicately.

Bruce: Just checked out the Vectorsite page. Very impressive. He describes Hunter's work on the earlier S HARP project. To catcth up with what Hunter is up to now, watch the video.

The important aspect to any ballistic launch from the planet's surface is that it will require a separate booster phase to circularise the orbit of the payload. That is why the payload includes a specially designed rocket to withstand the g-forces of space.

Hunter's group plans to begin with launching liquid fuels and eventually water and other necessary volatiles as payloads. It makes sense for them to also launch inflatable habitats and components for space tugs (for Earth orbital work) and GEO to lunar orbit shuttles to support more intensive lunar exploration.

Sunday, 17 January, 2010  
Anonymous Anonymous said...

After reading the Popsci article I have to ask: Will the Next Level use mixed measurements, or will I finally be forced to use the metric system?

Monday, 25 January, 2010  
Blogger hcm1955 said...

This might be a great way to launch the 40,000 km of cable required for a starter orbital ring space elevator system


Paul Birch’s Orbital Ring/Space Elevator

Sunday, 31 January, 2010  

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