Pop-sci has been on here...

[john bunsenburner]

The last Popular Science magazine i've been reading had not one but TWO spudgun related reports!

One was of a hydrogen powered launcher, along the lines of a light gas gun, just that natural gas heats the hydrogen to crazy temperatures(instead of black powder compressing it). The hydrogen then accelerates a projectile down a 3,300foot barrel before the half ton projectile leaves the muzzle at predicited 13 000mph. The projectile is said to experience 5000Gs during the ride. The entire gun will be submersed under the ocean. Its use? To fling supplies into space for 250$ instead of 5000$ per pound. The project would cost 500$ million, and could be done in seven years from now.

The other, project was built by two mates. It consists of two huge propane tanks(1000gallons each) welded to a 100 foot metal barrel via a 'T shaped fitting', the valve is a butterfly valve. It is said to operate at 100psi and shoot anything that fits into the barrel. To access the breach they use a door at the start of the barrel. The construction in mounted onto a trailer mounted elevation platform. The babe weighs 8tons IIRC and runs on 100psi, it will participate in THE pumpkin chuckin competition in Delaware.

[Insomniac]

Holy mother of... 3,300 mile long barrel? Impressive, to say the least (Or a typo )

[john bunsenburner]

Yup typo, thats supposed to be feet .

[jrrdw]

You better re-read that artical or find it online and link it to us. 3,300 "feet" is over a half mile long.

[john bunsenburner]

Here Mr. I-don't-trust-anything-i-did-not-see-with-my-very-own-eyes...

[psycix]

Sweet.
Kinda weird, heating the hydrogen and THEN opening a valve.
That will need to be timed precisely. Would it be a "valveless" valve?

[john bunsenburner]

I don't see why they don't put a vacume in the barrel to aid acceleration. I like the fact they reuse the hydrogen instead of letting it go to waste, though the whole idea sounds a tad too scifi to ever be made real, but pretty cool nonetheless.

[D_Hall]

The problem with gun-launch of objects intended for orbit is that you have to have a rocket as part of your payload. Without the rocket, you put yourself into an elliptical orbit that unfortunately brings you to perogee below the surface of the Earth (that's bad, mmmkay?). To avoid this, you must modify your orbit once clear of the Earth's atmosphere. This requires a rocket motor.

Suddenly, your "simple" system just got a whole lot more complicated....especially when you factor in the requirement to survive 5000 Gs.

Gun-launch to orbit has been a pie in the sky dream for a lot of years. I predict it will continue to be at the time of my death.

[jackssmirkingrevenge]

I was waiting for D_Hall's reply

[D_Hall]

LOL... Looks like we've had this conversation before.

[rp181]

I agree. Popular science is vry bad at this kind of stuff.
For example, every single issue (excluding one or two) has something about the "new personal jet is finally here".

while where at that, Im going to bet thats not going to happen for a long time, thats a total infrastructure change.

[john bunsenburner]

I enjoy reading it, mainly because it is the only english bit of writing i get my hands on beyond school books, makes me feel...international. Also here and there they have things that are intresting, or so damn absurd that it is entertaining. I am a big fan of T.Grey's reports which are chemistry focused, and the mythbuster type of nerdyness which is captured very well within the the words of pop sci.

[ramses]

Apparently you didn't read the table of contents. They gave a link to "A Pneumatic Hot-Dog Cannon"

It uses a tiny solenoid valve to actuate an air cylinder, which opens a 1" butterfly valve... And they claim that this is better than a sprinkler valve...