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A Space Cannon That Might Actually Work
Unequivocal writes "Chalk another one up to Jules Verne. Physicist John Hunter is proposing a space cannon with a new design idea: it's mostly submerged. 'Many engineers have toyed with the [space cannon] concept, but nobody has came up with an actual project that may work. Hunter's idea is simple: Build a cannon near the equator, submerged in the ocean, hooked to a floating rig ... A system like this will cut launch costs from $5,000 per pound to only $250 per pound. It won't launch people into space because of the excessive acceleration, but those guys at the ISS can use it to order pizza and real ice cream.' Though it won't work on people, with launch costs that low, who cares?"
The last guy with a plan to build a super-cannon (a Canadian named Bull) did some work for Saddam Hussein. The Israelis didn't like that much, so they murdered him.
I've calculated my velocity with such exquisite precision that I have no idea where I am.
Here is an interesting "tech talk" at Google where John Hunter explains the workings of the cannon:
http://www.youtube.com/watch?v=1IXYsDdPvbo
You could shoot a rocket from a cannon, meaning you'd need less fuel (meaning a smaller fuel tank, meaning even less fuel) to get it up to speed.
I'd rather you rationally disagree than irrationally agree.
Seeing as ice cream is an emulsion if it gets warm enough it could fractionate into a much less tasty brew. However, if you keep ice cream very, very cold, it shouldn't be terribly affected by the g-forces if packaged properly. The real problem is what to do with real ice cream in an environment like the ISS where real ice cream can cause problems by virtue of the fact that loose fluids and crumbs need to be kept at a minimum for various reasons.
Sigs are too short to say anything truly profound so read the above post instead.
Correct me if I'm wrong, but 13,000mph isn't fast enough for any kind of stable orbit.
Wow, that article is horrid. They don't even mention Hunter's startup company: Quicklaunch. On that page you'll find his Google Tech Talk on the subject which answers many of the questions that people are asking here.
How we know is more important than what we know.
10 mins into the Google Tech Talk he gives a slide with the amortization cost per lb. About 20 mins in, he breaks the project up into phases and costs needed to complete each phase.
http://www.youtube.com/watch?v=1IXYsDdPvbo
It's worth watching the video for more info on G-Force hardening, Hydrogen re-capture, per-lb cost and project milestone/costs.
-Malakai
A Dragon Lives in my Garage
You have to shoot a rocket from a canon anyway. If you don't, you just end up shooting yourself in the back. You can't put something in orbit solely with a gun.
Also Russian tanks starting from T-64B can shoot missiles from their cannons.
"It's such a fine line between stupid and clever" -- David St. Hubbins, Spinal Tap
Do you realize just how far away the moon is from Earth?
This to-scale image should give you an idea of just how ridiculous this idea is.
http://en.wikipedia.org/wiki/File:Speed_of_light_from_Earth_to_Moon.gif
Keep watching the Tech Talk, he 'rails' on rail guns.
Basically, world record for rail gun right now is 5.5 km/s, after 200 million being spent on it. World record for Hydrogen gas gun is 11.2 at a fraction of the cost. Energy storage costs and other factors kill using electric for so large of a project.
He spends quite a bit of time discussing it when he goes over the history of rocket/guns, about 25mins in I think.
Also, he was paid by the navy to make gauss guns and rail guns, he just doesn't seem them as the right tool for this.
-Malakai
A Dragon Lives in my Garage
The real key demand for this technology is launching propellants to an orbital depot. The political climate has changed (temporarily I would say) so it's ok to talk about propellant depots again. ULA are doing some interesting research. That's actual hardware being risk reduced there. Once you have propellant on-orbit you can plan deep space missions using Soyuz class vehicles - going beyond LEO doesn't need Saturn class launchers. That's the cost comparison that we have to look at.. not "is it cheaper than Soyuz?" but "is it cheaper than Apollo?"
How we know is more important than what we know.
This was short on details, but the military builds electronics into some bullets that function at 15,000 G's. Napkin math says that would need a 1 mile long barrel to reach the 13k mph quoted in the article. if it was 5 miles long your 3500 G's you could launch about anything submerged in a liquid (typical wrist watch survives this without the liquid.) So about the only thing they couldn't launch is something living.
But even at 1/2 mile their still under the accelertion of a gun, so wouldn't even deform anything made of lead. So all non electronics, probably even most de-activated electronics submerged in liquids.
The man doesn't seem like a quack to me: http://en.wikipedia.org/wiki/Project_HARP
Also, the only mentioned test wasn't exactly a failure what I see; it just revealed some problems, which is understandable with such project.
(and y'know, I was aiming more at Funny...)
One that hath name thou can not otter
... is that it also lets you drop 1000 lb on any spot on the planet (if you don't mind it coming down at 13,000 MPH or so).
So your project ends up as the target of a lot of governmental "gun control" activity.
Look what happened when Iraq tried it (using one that was built into a mountain so it couldn't be aimed at most terrestrial targets): Mossad assassinated the designer mid-project, governments seized critical parts as they were being shipped, and finally the conquering army made them destroy the remainder of the project as a condition of the cease-fire.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
The idea is to get something into orbit, not shoot it away from the planet. To go into orbit around Earth you have to fire the projectile with LESS than escape velocity.
If you just fire a projectile, with no rocket, into a non-escape orbit, the only possible orbits are those that intersect the firing point. That is, the projectile will go all the way around the planet and hit you from behind. You've just shot yourself in the back in the most dramatic way possible.
I think you dropped a zero or two somewhere in your calculation. Escape velocity from the Earth's surface (neglecting air resistance) is 7 mi/s. 7 mi/s * 60 * 60 = 25000 mph. Escape velocity is about twice the speed they're aiming for, plus you're going to burn a decent amount of that speed off in the atmosphere. Emphasis on "burn." Which makes perfect sense since they're talking about delivering payloads to Earth orbit, not to some solar orbit, which wouldn't be very useful.
The japanese dreamt of it for a while ! http://en.wikipedia.org/wiki/Samurai_Pizza_Cats
Even if a 1.5 light second long cable were feasible you'd still have to deal with the fact that, as far as I understand, the anchor would have to be in geosynchronous orbit. Since the Moon isn't in geosynchronous orbit, the surface moves relative to the Moon you'd end up winding the cable around the planet.
Escape velocity is 11.2km/s, to reach 11.2km/s with a 30 meter barrel you would need ...
The idea is to put something into orbit, not to fire it into deep space, never to be seen again, so there's absolutely no reason you want to reach 11.2km/s. Try rerunning your numbers using the actual figures rather than numbers you pulled out of your butt. The proposed barrel length is 1100m, and the velocity coming out of the barrel would be 6m/s.
"Convictions are more dangerous enemies of truth than lies."
A bit of math here. Escape velocity on earth is 10.735Km/sec, Acceleration at 6G = 9.8*6=58.8 M/Sec^2. 10735/58.8 = 182.5 Second to reach escape velocity
Distance travelled during that that time 10.735*182.5/2 = 979 Km. Basically to accelerate a body to escape velocity with a steady 6G acceleration would require a tube almost 1000 KM long. Even popping up to 10G the tube would be 585Km long.
These calculations do not even take into consideration deceleration due to drag.
By the way, escape velocity is approximately Mach 31. Building a 1000 pound object that can go through the atmosphere at that speed would be difficult. Cannon rounds from an M1 only go Mach 5.
The original Popular Science article is a much better read and includes additional detail, including the fact that the projectile will experience 5,000G forces. Definitely not for human passengers.
'The tyrant will always find pretext for his tyranny.' - Aesop's Fables
They don't need to worry about the wave motion because most of the structure is below the water. IIRC submarines on the surface don't really pitch and roll. The picture in TFA shows the structure rigidly connected to the control platform but probably that wouldn't be required.
There are currents at different levels but I don't think it would be a great issue. The currents are not swirling around like in a river, in the open sea it would be fairly constant and could be accounted for by tensioning the structure
I don't know about catching the packages, but aiming the thing might be somewhat tricky. Perhaps they would need to be like ICBMS with a limited amount of steerage ability so that the orbit could be adjusted while it was still in the atmosphere.
Sorry, but I don't see the benefit of floating the cannon in the ocean.
1. You can aim it. This is a big fucking deal
2. Weight is not a factor. You can build your cannon as heavy and as strong as you please.
3. You don't have to worry about safety because any failures will happen underwater and away from land. This is also a big fucking deal
Depends on what you mean by exotic. If you mean nuclear, there's not much evidence. Well, there's evidence that Saddam put money into developing them, just no evidence that the money bought anything more complex than a centrifuge. There are, however, numerous documented examples of Iraq using chemical weapons, including some tests on their own population. Specifically, they are known to have had sarin, tabun and VX, and may have had others. He also put a lot of money into developing biological weapons.
As the grandparent points out, if this money had been invested in equipping and training a conventional force instead, he'd probably still be alive and in a strong position. Chemical and biological weapons have almost no tactical utility and very little strategic value. A well-trained and well-equipped conventional army has both.
I am TheRaven on Soylent News
I never cease to be amazed of some of the silly things that are published on Slashot.
A system like this will cut launch costs from $5,000 per pound to only $250 per pound. It won't launch people into space because of the excessive acceleration, but those guys at the ISS can use it to order pizza and real ice cream.
The ISS obital inclination is 56 degrees. Any 'ice cream delivery' made from a 0 degree inclination transfer orbit would have a relative velocity of about 7500 mph. The ice cream would effectively become an ASAT weapon.
an ill wind that blows no good
Well, I can't claim credentials like yours, but lately I've thought that a launch loop would be a much better idea than any of the gun or elevator ideas. It's gentle enough (~ 3g acceleration) to put people in orbit easily, requires no new materials, and supposedly could make multiple launches per day. Your thoughts?
I prefer rogues to imbeciles because they sometimes take a rest.