A Space Cannon That Might Actually Work 432
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?"
We need more ideas such as this (Score:5, Insightful)
It'll always be more expensive to send people up, at least in the near term, but we will need to send up a lot of other things that could be done in unmanned launches using this or another innovative technology. Ideas such as this could work; it's merely an engineering problem at this point.
Ice cream? (Score:2, Insightful)
avoid lifting unused propellant (Score:4, Insightful)
Re:Hunter should watch his back (Score:5, Insightful)
John Hunter: Note to self: Try to avoid working with Saddam Hussein.
Re:We need more ideas such as this (Score:5, Insightful)
Re:atmospheric stresses (Score:4, Insightful)
Its not actually that preposterous. Some of the more advanced artillery shells are effectively rockets shot from cannons.
Re:We need more ideas such as this (Score:4, Insightful)
Who's going to buy the tylenol for the whales?
Acoustics are a bitch.
Re:Ice cream? (Score:3, Insightful)
Actually there is very little in the way of supplies that could handle that acceleration. Maybe freeze dried soup, maybe water, but very little else. You wouldn't dare send gasses, electronics, whole foods (even canned) or replacement parts.
The whole idea hinges on the un-compressibility of water, making the extra long cannon easier to construct, but if you've ever seen a depth charge explode you know that only works so far. It also mentions an increase of pressure of 500% which is no where near enough. Skuba tanks easily exceed that. Somebody dropped a zero.
Re:More wildly optimistic cost estimates (Score:3, Insightful)
To fire it from a cannon the G force is going to be astronomically high. Very little is going to be able to survive that type of acceleration without massive damage. You could certainly fire a block of metal that fast without worry that it's ruined (though it will likely deform) but you put a 2 billion satellite in that and it's going to be absolutely destroyed by the acceleration. Even with a conventional rocket they spend several million dollars packing and testing the container the satellite is shoved into to make sure the vibration and acceleration won't damage the bird during launch.
Now you might be able to use this to build a large space station in orbit if you build everything in orbit including forging every piece because you could use this to blast up the raw materials but in reality it's not going to be launching anything but raw materials due to the acceleration. Once you exceed a certain amount of G's and nothing mechanical or electrical can survive it without being damaged or destroyed. Rapid acceleration doesn't just damage living organisms, it can destroy almost anything.
Re:We need more ideas such as this (Score:5, Insightful)
There is the little matter of finding something to make a space elevator out of. Nobody knows how to make a nanotube cable strong enough to do the job.
I guess that's more a materials science challenge than an engineering one, but it certainly hasn't proven to be easy to solve.
Re:We need more ideas such as this (Score:5, Insightful)
Perchance, are you in management? Or Sales?
Re:We need more ideas such as this (Score:5, Insightful)
design the cannon like a thermos bottle as sounds require a medium to propagate which is why in space no one can hear you scream.
So your going to have explosive pressure on one side, huge water pressure on the other side, and a vacuum in the middle?
Re:Duh, we bomb the shit out of those who have the (Score:4, Insightful)
Yes gents, Saddam Hussein could have given us cheap access to space ensuring new area of prosperity for mankind, and era of space colonization...and we killed him!
OR Saddam hired a quack who was assassinated before he was revealed to be a complete phoney.
Had there been something resembling a successful test, I'd say we may have screwed up, but the only mentioned test was a failure. Also I don't hold Saddam's judgment in very high regard, it doesn't sound like there was much peer review on this project, and the US tends to take useful technology and scientific talent from it's enemies rather than destroy it.
Therefore I doubt this was anything that would have been useful, but I suppose we'll probably never be able to verify or deny your conspiracy theory.
Re:Velocity (Score:3, Insightful)
Yep. The only stable orbit that intersects the planet's surface is an escape hyperbola. An ellipse that does it once does it multiply. POW!
But by getting high enough above most of the atmospheric friction and having some dwell time there before falling back you've solved most of the problem. Circularizing the orbit (or at least raising the perigee above the atmosphere) is a minor job for a rocket motor compared to clawing its way up from a standing start while carrying the fuel for the whole launch.
Even getting a running start with most of the get-to-orbital-altitude work done before starting the motor and fuel consumption is a tremendous improvement.
Also: Muzzle velocity is MORE than enough to start a scramjet. I wonder if the free oxidizer would be more of a help than the extra engine weight is a hindrance.
Re:We need more ideas such as this (Score:4, Insightful)
I think they'd need to tether it to something in a geosynchronous orbit.
Re:We need more ideas such as this (Score:5, Insightful)
actually i would say a space elevator is a funding problem.
Speaking as an aerospace engineer, I would say building a space elevator is a reality problem
Re:More wildly optimistic cost estimates (Score:3, Insightful)
5000 G. That's about the equivalent of dropping something out a third-story window onto a concrete surface. Your laptop won't survive it, but bulk supplies (food, water, oxygen) will. Properly-designed equipment will as well: when your laptop hits the ground, it's not the computer chips themselves that break, but the joints -- electronic fuses in artillery shells don't have any trouble. You could even put entire satellites into orbit this way. The packaging and testing you mention is a result of the high cost of launching things right now: to keep the total weight down, the average satellite is very fragile. Build one with volume being the limiting factor rather than weight, and you'll get a much more durable object.
Re:Duh, we bomb the shit out of those who have the (Score:3, Insightful)
PS. If a supergun has a basic design similar to German V-3, it might be almost bearable to humans...
No. If you work out the G forces required at launch to ballistically get into orbit, solid objects such as electronics will not survive. Live subject would not have a chance.
Re:Duh, we bomb the shit out of those who have the (Score:5, Insightful)
I think anybody on Slashdot who refers to Saddam as the martyred hero of space travel is not being serious.
If Saddam had taken half the resources he put into exotic weapons and invested in his conventional forces, he'd be alive today — and probably the most powerful man in the Middle East. But training and equipping armed forces is hard work. A lot of dictators just can't be bothered. Instead they model themselves on the villains in James Bond movies: lots of parties, gloating, glitter, and top secret projects, but none of the dreary stuff that has to do with actual governing.
Comment removed (Score:4, Insightful)
Re:Downside of being able to launch 1000 lb to LEO (Score:2, Insightful)
Sure, it wasn't able to shoot at most targets. Just ones that happened to be 800 miles west of iraq. For example, the entirety of Israel.
Re:Fuck whales. (Score:3, Insightful)
That's like someone building something next door to you that's so loud that it's literally painful and saying, "Fuck you. Seriously. Why should you get dibs on the whole town."
Re:Duh, we bomb the shit out of those who have the (Score:4, Insightful)
What does that remind me of.......
In all seriousness, Saddam only thought he had all of this doomsday projects in the works. The reality, which is supported by evidence apparently (from what I hear), is that most people working for Saddam were terrified of him and his sons and flat out lied or blew smoke up his ass about how far along they were with his ultimate weapons.
The only thing more tragically retarded and pathetic is the fact that a president and some intelligence agencies fell for the same bullshit. Or did they? :)
Re:Duh, we bomb the shit out of those who have the (Score:3, Insightful)
Exotic weapons? Saddam Hussein? Uh, citation please.
Mind, you, I said the same to Colin Powell...