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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?"
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.
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.
I want to order pizza and ice cream on earth, delivered by cannon.
it works on people, so long as they're already dead. Why does this matter? Because now I can get the Star Trek space-burial I always wanted!
stuff |
This subject line says it all when it comes to efficiently placing things in low earth orbit.
Here is an interesting "tech talk" at Google where John Hunter explains the workings of the cannon:
http://www.youtube.com/watch?v=1IXYsDdPvbo
If you try to launch an object from the surface of the Earth using a "cannon" the projectile won't be doing anything other than decelerating throughout its flight and this means bringing the projectile to very high velocities where atmospheric heating and stresses become major problems. Then again, launch its self may be a problem as the Hydrogen propelling the projectile is detonating at an extremely high temperature and pressure. Small nitpick as well from TFA:
A big reason space food is what it is instead of the Earthling food we're all accustomed to has to do with keeping the station reasonably clean and experiments doubly so. Crumbs and fluid loose in the station can cause problems.
Sigs are too short to say anything truly profound so read the above post instead.
http://en.wikipedia.org/wiki/Project_Babylon
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!
PS. If a supergun has a basic design similar to German V-3, it might be almost bearable to humans...
One that hath name thou can not otter
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
Min orbital velocity = 7.6 km/s
Earth Escape Velocity = 11.2 km/s
Funny coincidence, world record for hydrogen gun == 11.2 km/s
These guys plan to have the gun propel the projectile to 6.0 km/s, and then the projectiles themselves are rocket motors that will add an additional 3.0 km/s. That gives them enough acceleration to reach orbital velocity and take into account friction/gravity losses.
The reason they plan to limit the gun to 6.0 km/s is because that requires the hydrogen gas to only reach 1700 kelvin, which after taking into account heat exchange with the barrel, it ends up being a few hundred kelvin below the melting point of steel ( the barrel ).
-Malakai
A Dragon Lives in my Garage
Make it long enough and it CAN launch people. (You'll need good streamlining to avoid nasty deceleration when it leaves the muzzle, though.)
The ocean is DEEP. Something that's roughly neutrally buoyant (i.e. a gun barrel supported by floats distributed along its length) needs to spend negligible structural strength supporting itself. (It only needs to be strong on any part that protrudes from the water - which might be a lot to avoid sinking it when it recoils.) You might want to put "helper combustion chambers" along it periodically to boost and smooth the acceleration if you want to launch live stuff though.
Also you can make it larger diameter and put sabots on the projectile while it's in the barrel to reduce the internal pressure variations or fire very dense loads. (Doesn't really help the materials strength issues, though, because the curvature lessens as diameter rises.)
Recoil? By being submerged it's an inside-out hydraulic shock absorber. B-)
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 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
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.
Dear sir,
If we twisted the cable around the earth, and the cable was connected to the moon on the other end, we could tow the moon back here.
Whichever country it landed on would then be the largest country in the world. (Although it would also be squished.)
We could use this technique to explore space cheaply.
I will authorize funding for space exploration only if this method is used.
Regards,
Your Elected Representative
PS - As a side benefit, we can invade the moon.
-- IANAL, this isn't legal advice, and definitely isn't legal advice for you. Also, Squee!
Seriously.
Why should whales get dibs on the whole ocean.
People like you are the reason Kirk had to go back in time to the 1980s. Sheesh.