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A Cannon for Shooting Supplies into Space
Popular Science ^ | 1/15/10 | Amina Elahi

Posted on 01/15/2010 3:00:45 PM PST by Reaganesque

John Hunter wants to shoot stuff into space with a 3,600-foot gun. And he’s dead serious—he’s done the math. Making deliveries to an orbital outpost on a rocket costs $5,000 per pound, but using a space gun would cost just $250 per 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.”

How to Shoot Stuff into Space

STEP 1: HEAT IT

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.

STEP 2: LET THE HYDROGEN LOOSE

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

STEP 3: TO INFINITY AND BEYOND

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.


TOPICS: News/Current Events; Technical
KEYWORDS: banglist; bigbanglist; boomlist; cannon; shooting; space; supplies
Cool stuff! Although, for some reason, I can't get the voice of Daffy Duck out of my head screaming "DUCK SEASON!! FIRE!!!"
1 posted on 01/15/2010 3:00:46 PM PST by Reaganesque
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To: Reaganesque

Mother of All Spud Guns..


2 posted on 01/15/2010 3:03:10 PM PST by rahbert (Bop Bop, dibidip dibidip....)
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To: Reaganesque

This makes me think of the book “The Moon is a Hash Mistress” by Robert A. Heinlein but in reverse.


3 posted on 01/15/2010 3:09:40 PM PST by Rogle
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To: rahbert
Mother of All Spud Guns..

The ULTIMATE Polish Cannon [thats what we called them at Penn State] !!!

BTW: We used Sunoco 260 as propellant ...

4 posted on 01/15/2010 3:12:39 PM PST by Lmo56
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To: Reaganesque
We need this for the exact moment that the US government shoves their health care bill down our throats.

Bombard Washington with high velocity potatoes.

5 posted on 01/15/2010 3:14:44 PM PST by politicket (1 1/2 million attended Obama's coronation - only 14 missed work!)
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To: Reaganesque

Should be very practical for getting fuel, food, water, structural components, etc to orbit, and maybe a lot more. American Exceptionalism at work, no gov’t help needed, thank you very much!


6 posted on 01/15/2010 3:14:53 PM PST by bigbob
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To: rahbert
"Mother of All Spud Guns.."

Methinks any spuds fired through THAT will end up "mashed potatoes".

7 posted on 01/15/2010 3:15:39 PM PST by Wonder Warthog
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To: Rogle
That was electromagnectic; this is much closer to Verne's From The earth To The Moon, which utilized a cannon.
8 posted on 01/15/2010 3:20:42 PM PST by ApplegateRanch (I think not; therefore, I don't exist!)
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To: Reaganesque

Son of a..... That's gonna leave a mark.

9 posted on 01/15/2010 3:20:46 PM PST by DogBarkTree
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To: Reaganesque

Gerald Vincent Bull (March 9, 1928 - March 22, 1990) was a Canadian engineer who developed long-range artillery. He moved from project to project in his quest to economically launch a satellite using a huge artillery piece, to which end he designed the Project Babylon “supergun” for the Iraqi government. According to Slate, Bull “is commonly understood to have been assassinated by the Mossad”[1], a killing which took place outside his apartment in Brussels, Belgium.


10 posted on 01/15/2010 3:22:44 PM PST by buccaneer81 (ECOMCON)
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To: Reaganesque

When it reaches orbit, a rocket engine firing would be required for it to match velocity with its destination. I don’t see that in the diagram.


11 posted on 01/15/2010 3:23:11 PM PST by bsf2009
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To: politicket

Fire politicians into outer space.


12 posted on 01/15/2010 3:25:16 PM PST by DTogo (High time to bring back the Sons of Liberty !!)
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To: Reaganesque

13 posted on 01/15/2010 3:26:45 PM PST by paulycy (The Liberals' DOUBLE-STANDARDS are HATE CRIMES.)
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To: Reaganesque

Exactly how do you keep the recoil from sending that gun and it’s firing platform a mile deep in the ocean?


14 posted on 01/15/2010 3:30:20 PM PST by bad company (There are no illegal guns, just undocumented firearms.)
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To: buccaneer81
Gerald Vincent Bull (March 9, 1928 - March 22, 1990) was a Canadian engineer who developed long-range artillery. He moved from project to project in his quest to economically launch a satellite using a huge artillery piece, to which end he designed the Project Babylon “supergun” for the Iraqi government. According to Slate, Bull “is commonly understood to have been assassinated by the Mossad”[1], a killing which took place outside his apartment in Brussels, Belgium.

Check out the movie, "Super Gun", about Bull [Frank Langella] ...

Very instructive - he actually built a 1/20th scale prototype that fired a projectile that hit the target at like 125 miles ...

Full-scale gun was supposed to be able to hit Israel - but he never got that one built. Mossad got him first ...

15 posted on 01/15/2010 3:30:24 PM PST by Lmo56
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To: Reaganesque

5000 G’s. That would seem to me to limit the type of satellites that could be launched to very simple rugged orbs. Could work I suppose. OTOH, this would make a great weapon. Easy to launch the warhead from an ICBM.


16 posted on 01/15/2010 3:34:52 PM PST by InterceptPoint
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To: bad company

This may stimulate some responses from people who KNOW, but I would guess that, just as if you hit the water after falling from an aircraft at 10,000 feet, the water would feel somewhat like concrete, I suspect a “10,000+ mph recoil would make the water act pretty much like a LOT of concrete. I noticed the fins in the picture.


17 posted on 01/15/2010 3:48:23 PM PST by RobRoy (The US today: Revelation 18:4)
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To: bad company

“For every action there is an equal and opposite reaction.” However, when the mass of one object being acted upon is significantly less than the other object being acted upon, the “equal and opposite” force has a greater effect on the smaller mass than the bigger. So, the bullet goes flying while the gun stays relatively motionless.

I am such a nerd.


18 posted on 01/15/2010 3:54:55 PM PST by Reaganesque ("And thou shalt do it with all humility, trusting in me, reviling not against revilers.")
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To: bad company

Here’s an example: If you pick up a rock and you throw it, you are applying force to that rock. But, at the same time the rock is exerting that same amount of force against your hand.(the “equal and opposite” reaction) The reason it goes flying and you don’t is that your mass is way bigger than the rock.


19 posted on 01/15/2010 3:59:35 PM PST by Reaganesque ("And thou shalt do it with all humility, trusting in me, reviling not against revilers.")
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To: Reaganesque
IIRC, Gerald Bull had this idea as well, at least for launching satellites. When he went to work for Saddam, things didn't work out very well for him.

Mark

20 posted on 01/15/2010 4:05:51 PM PST by MarkL (Do I really look like a guy with a plan?)
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To: bsf2009
When it reaches orbit, a rocket engine firing would be required for it to match velocity with its destination. I don’t see that in the diagram.

Baring atmospheric effects, I believe that the natural trajectory of such a cannon would be either a parabola (if the payload was launched with an escape velocity) or an ellipse (with an orbit that intersects the earth).

21 posted on 01/15/2010 4:20:04 PM PST by Ronaldus Magnus
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To: Reaganesque

Air resistance after launch is going to go up with the square of velocity; even if the tube were evacuated prior to launch, the required energy would be the square of the initial velocity. I’m not sure there would be an asymptotic limit to achievable elevation, but I find it hard to imagine anything resembling an orbit would be practical for a sea level launch. A shot from mountains would seem much more reasonable.


22 posted on 01/15/2010 4:50:44 PM PST by supercat (Barry Soetoro == Bravo Sierra)
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To: Ronaldus Magnus
Baring atmospheric effects, I believe that the natural trajectory of such a cannon would be either a parabola (if the payload was launched with an escape velocity) or an ellipse (with an orbit that intersects the earth).

For this thing to be useful for its claimed purpose, it must get its payloads above atmospheric interference. If the object reaches some elevation beyond which there is no natural interference, but below which atmospheric interference would be problematic, its orbit thenceforth must be either parabolic (leaving the Earth and never coming back) or else elliptical (with an orbit whose minimum altitude would pass below the elevation where atmospheric drag poses a problem). So some sort of additional thrust would be required.

23 posted on 01/15/2010 4:56:14 PM PST by supercat (Barry Soetoro == Bravo Sierra)
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To: Reaganesque

“Here at VW, ve prefer a trebuchet.”

24 posted on 01/15/2010 5:02:05 PM PST by RichInOC (No! BAD Rich! (What'd I say?))
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To: Reaganesque

Will they be showcasing this at Shotshow 2010 next week?


25 posted on 01/15/2010 5:18:14 PM PST by sockmonkey
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To: Rogle

At the end of the book they were building electromagnetic catapults on Earth.


26 posted on 01/15/2010 5:24:06 PM PST by magslinger (Cry MALAISE! and let slip the dogs of incompetence.)
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To: Reaganesque
This is a refinement of what I have been saying for a decade and a half, based on the old HARP concept. They were able to place sattellites in suborbital flight with a gun only about a hundred feet long. This looks very doable to me and opens up the solar system because we can shoot supplies into space to maintain a real space station and to start to develop moon resources!
27 posted on 01/15/2010 5:52:05 PM PST by marktwain
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To: bsf2009

I think a small rocket would be necessary to put it in precise orbits, but you might get most of the delta V you needed by manipulation of the fins on the atmosphere.


28 posted on 01/15/2010 6:04:07 PM PST by marktwain
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To: RobRoy

“I suspect a “10,000+ mph recoil would make the water act pretty much like a LOT of concrete.”

Well, conservation of momentum means that mass(projectile) X velocity(projectile) = mass(gun) X velocity(gun)

Say the projectile is 500 kg and 2 feet of gun tube weighs as much as the projectile. 3300/2 = 1,650, or the mass of the gun is about 1,650 times the projectile. The projectile velocity is 13,000 mph. The gun’s velocity is 13,000/1,650 = about 7.9 mph or about 12 fps.

The gun would might bob down under the waves for a bit and bob back up, but that would depend on how much was out of the water to start. I’d think you would want a couple of hundred feet out of the water, so it might not be a problem at all.


29 posted on 01/15/2010 6:17:53 PM PST by marktwain
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To: InterceptPoint
Easy to launch the warhead from an ICBM.

The launcher would be a sitting duck.

30 posted on 01/15/2010 8:28:09 PM PST by Mike Darancette (Obama's only 2012 hope; lose one or both houses of Congress in 2010.)
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To: Reaganesque

what about the water pressure on the barrel/tube at 1600 feet below sea level.

how do you keep barrel diameter constant aling it’s 3200 feet of length ?


31 posted on 01/15/2010 10:00:21 PM PST by lack-of-trust
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To: lack-of-trust; marktwain

what about the water pressure on the barrel/tube at 1600 feet below sea level.

how do you keep barrel diameter constant along it’s 3200 feet of length ?


32 posted on 01/15/2010 10:04:02 PM PST by lack-of-trust
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To: lack-of-trust
The picture is, no doubt, just an artist’s conception, but it appears that the projectile uses a sabot to increase performance. Current sabots are designed to deform a bit to seal the bore. No barrel is perfectly the same diameter all along its length. There are always some variations due to manufacturing tolerances.
33 posted on 01/16/2010 6:33:17 AM PST by marktwain
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To: marktwain

The drawing doesn’t match the description in the article, but the point remains.

V is a function of chamber pressure.
the higher the chamber pressure, the harder it is to maintain the barrel/projectile seal.

if the barrel is 100” in diameter, how much would it shrink at 1600’?

assuming the sketches are all wrong... perhaps the reason for floating this contraption in the oceans instead of building it on land is to use the ocean’s depth /pressure to do work for the system.

imagine this desing:
3200’ long, pivots at the mid point.
the “exit” end has a sealable cap.
the ignition chamber is divided into two areas as follows

projectile/oxygenchamber/valve/hydrogen chamber/piston/ ocean pressure.

With the barrel horizantal, the projectile is loaded, o2 and H are put into their respective chambers and then it is rotated to the verticle. The sea water pressing against open the valve and ad spark, 02 and H mix and ignite with a combined pressure of 25 atmospheres before ingnition.


34 posted on 01/16/2010 2:08:06 PM PST by lack-of-trust
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To: DTogo

You would have politician pate (you know, the French stuff that tastes like cat food).

I invited Dr. Hunter to the large aerospace firm where I was an engineer in the early 1990s to brief us on his light gas gun to orbit. One of our executives actually asked “Can we launch astronauts with the gun?”. Jaws dropped around the table. The executive was a former Marine test pilot. John calmly rejoined something about astronaut pate.

The idea is sound for robust payloads, e.g., fuel. However, in adddition to the 5000 Gs of acceleration, the projectile will suffer quite a shock when it hits the atmosphere at the end of the muzzle (a high speed valve allows the projectile to exit while keeping most of the air out). You lose a km/sec or so in atmospheric drag during the short transit. Lots of heating of the projectile occurs.

I like the idea of fitting the projectiles with precision guidance systems and having them reenter over an offensive country’s nuke research site at around 6 km/sec. You could launch heavier projectiles at around 7 km/sec and allow drag to bring the projectile back down below escape velocity. They’re gonna have to bury that bunker pretty deep!


35 posted on 01/16/2010 4:47:19 PM PST by darth
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To: lack-of-trust
“if the barrel is 100” in diameter, how much would it shrink at 1600’?”

The projectile is shown as finned, so I would expect a smoothbore. You would want it long and thin to combat atmospheric drag. We have a weight of 1000 lbs mentioned. If it had a specific gravity of 2 and was 10 times as long as bore diameter, the volume would be about 8 cubic feet and the diameter about 1 foot.

36 posted on 01/16/2010 8:16:01 PM PST by marktwain
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