starfire-space-cannon
prof_braino
Posts: 4,313
Dijya see this?
https://www.kickstarter.com/projects/1682852725/the-starfire-space-cannon
Remember, if it doesn't reach its fund goal, you don't have to pay. And if it does reach its funding goal, there will be a Space Cannon!
C'mon! Order the polo shirt!
https://www.kickstarter.com/projects/1682852725/the-starfire-space-cannon
Remember, if it doesn't reach its fund goal, you don't have to pay. And if it does reach its funding goal, there will be a Space Cannon!
C'mon! Order the polo shirt!
Comments
Maybe it's just me but this seems a bit nutty. (I know, this is what they said about the Wright Bros.)
I wonder why he isn't using magnetic railgun tech instead of powder charges...
But it looks fun!
Shooting several of these at Felix Baumgartner as he skydives from a balloon at the edge of space might just result in a profitable Pay-per-view event.
They live in CANADA. The whole place is a really big field. The closest neighbors they care about are in Mexico.
Even if a dart landed in Canada, they could pretty much shoot it in any direction and not hit anybody. And if by accident, they hit the French language police office, no one would complain.
Seriously, though, watch the video. He's aleady got stuff under control with government regulartions. Maybe he heard about the other artilery guy from Canada. http://en.wikipedia.org/wiki/Gerald_Bull
The Canooks aren't quite as anal with stupid regulations as their brothers further south (the beaurocracy is not so large), and I bet they would love to get into space for 1/1000 the cost of a NASA effort.
Its completely impossible. I double dog dare you to back it.
THATS why! Didn't you see how the third shot rips the dirt off the ground!?!? I love this stuff!
I think zero to 4,000 mph in 45ft is about 12,000 g's.
Years ago I dreamed up a space cannon that was thousands of feet long, was a vacuum inside and had charges all along it's bore to "gently" accelerate the payload. I doubt I was the first to dream one that up...
I had a though about fully sequential combustion by lining the barrel with propellent.
This propellent must have a special characteristic. It must be able to be detonated only by the high pressure gas contained behind the projectile.
As the projectile passes more propellent is consumed. Effectively giving a constant pressure behind the projectile.
Duane J
But his ideas had merit and inspired another project http://en.wikipedia.org/wiki/Super_High_Altitude_Research_Project but I really doubt that a space cannon is amenable to amateur construction.
Awesome idea! But, if the space journey gets them lost in space, maybe they will need a power source. How about an
engine that burns water? (pure water to hydrogen, electroylsis) I just happen to be working on that, and have attached
a picture of it. What do you think?
(working on the injector, then it is finished)
This is a 5 - 10 watt model version. It can turn now on 140 PSI of air.
After I finish the project, I will make a 17 KW generator. This can be used for your electric car, power your house,
or your boat. On your boat, you are floating on the fuel. In your house, any power not used, feeds back into the power
line, and you get a check from the power company.
I will use a basic stamp to control the combustion timimg, via magnetic switches on the right of the shaft.
The basic stamp will control the speed, monitor the power, and after a short run, will initiate a "clean cycle".
I needed the hp/stamp combo to help analyze all the parameters of the engine
So, what do you think?
Correction; The magnetic switches(reed) are on the left side, for controlling exhaust/injection timing.
Working on this, amongst other projects of mine................:)
I think the first tests are with the 45 foot gun. There was mention of a 65 foot gun. And if the idea proves out, he could go bigger.
I saw the youtube science class demo from MIT(?) where they used 1" PVC pipe with mylar on the ends, and a ping pong ball inside. They evacuated the pipe, then punctured the back with a tack, and bounced the pong pong ball off the teacher. Even with a thick pad, it left a welt. I want to try this with my lab assistant, but he keeps climbing out of the tube.
I think you should start a separate thread in the projects section, and post your progress. I am looking to start Brown Gas generator experiments this summer. 140 PSI of HH + O2 sounds like it would make a cool noise!
The barrel is so small that it doesn't make any sense. You have to punch through the atmosphere and have enough energy left to make it to the Karman line. You can't do this with the stated size.
He quotes 60,000 psi as (optimistically) the highest pressure you could get from the explosives. But that limits the energy that you can get in the projectile by (pressure) x (volume). After you calculate that, calculate the impulse from pushing the air out of the way - times some ballistic coefficient.
In doing this, you have to choose the mass and the dimensions of the projectile. If you make it too small, then its momentum will be insufficient to get it through the atmosphere. If you make it too large, the barrel can't accelerate it (based on the energy limitation) to a sufficient speed.
It's even more depressing that not just getting 1/2 the way to space. The majority of our atmosphere is within a 10 miles or so of the surface. If you can get through that, altitude becomes the primary challenge. But he can't possibly get that far. Any reasonable combination of parameters I can come up with leaves it turning around by 15 km.
http://www.howstuffworks.com/space-elevator.htm
Awesome! I recommend for your brown gas producer, to start off with a di- or polyprotic acid. That will get you the hydrogen, but it will only last as long as the ions released. You
will need a catalyst, as I have developed.(Its a secret). It reduces the amp draw for the electroylsis from 20 amps to .5 amps, with slightly more hydrogen gas. I have tried
molecular dissasociation of water, but that takes longer. the right mechanical spacing for the oscillations are necesary. The basic stamp has PWM, which is a great thing
to produce more amperage "heat". But of course, it is not, but produces the larger effect.
hydrogen is dangerous; when a cubic millimeter hydrogen bubble explodes, it sounds like a M80 firecracker going off. Static electricity will set hydrogen off.
Just about anything normal will set it off, so I look at hydrogen as being angry all the time.
As for the star fire cannon, the PSI is great at the begining, and any material used must withstand this pressure. I am confident there is potential for this
device.
Actually, the 45 foot barrel makes abolute sense for initial experiments. Some experiments bear a cost. Many of us have discovered that its easier to start with small steps, although your mileage may vary. Since his plan (as described in the kickstarter materials for those that do not click links) is to start with a 45 foot barrel, then move to a 65 foot barrel, and then make further desicions based on the data collected; I find the campaign's reasoning, at least, to be sound.
@ AlanSe: Since you know how to do the calculations, may I ask a favor or two? Could you re-run the calculations to find the following:
1) What is the expected perfomance of a 65 foot barrel of the same diameter?
2) what is the shortest barrel and smallest diameter that will punch through the atmosphere (stated 10 km?) using the stated propellents?
Here you go:
I put the code for the simulation here:
http://pastebin.com/9EhREfr6
This is the full-form of the calculation, and much better than the limit-case I had been using. You haven't specified a projectile mass, and it's obvious that you would want this optimized. So that's what the above image shows. In the low mass range, it tapers off due to air resistance. In the high mass range, the gun's energy isn't sufficient to accelerate the projectile to sufficient speed.
It's still not half way there. And I used a drag coefficient of 0.3. Other references suggest values as high as 0.75, although I think that might be a little excessive. It is very very difficult to imagine that it could possibly be any lower than this.
You could still improve it by starting the launch at the top of a tall mountain. But I'm not here to fix it. It probably won't get funded in the first place. By all means, I'm a fan of space development, and I think this kind of project can be a good small step toward that. The problem is that people on the Kickstarter are explicitly claiming that their calculations show that it will work. That's because they're plugging in something like h=1/2gt^2.
If power of PSI is the goal, then I would recommend looking into the russian's tensor beam. More PSI for the watt. Dr. Potlenkov, I think. (?)
Just imagine - you're moving at approximately 1000mph to the east right now, just sitting there! (well, if you're near the equator anyway. I'm probably only doing around 700
So I can't see ANY way that this cannon concept could launch any useful projectile actually into ORBIT... but maybe I'm missing the point.
... with a standard gun. That means a single propellant charge. The different of this unit is that is is to have MULTIPLE charges. Look at the graphs for when three charges are used in sequnce. Can yo work that into your equations? How many charge would it take to reach space?
I think he mentions that in one of the videos when he's holding that missle looking dart.
Good, I just want help with the math. I only budgeted $50 for this, and thats going to the Canadian.
Actually, if we work out the equations and determine what "work" means in your sense (what it would take to get into orbit) and to what extent this gun will apporach that, it stands avery good chance of getting funded.
The claim to fire the small gun at least 4 times, and the big gun at least 6 times. They claim sub orbital flights, the projectile goes up, then comes down. Are you confusing the project goals with the potential/possibilities?
They never say they are going to launch a cat or a toaster into orbit. (in Phase 1 or Phase 2, the scope of this kickstarter, AFAIK)
They claim they are going to shoot a really big gun with multiple propellent charges to get a contimuous pressure during firing, as opposed to a single initial pressure as on a standard gun. They have already demonstrated this in the video.
It ALREADY "works", now they are going to try to develop it and run some tests.
Then isn't a good old weather balloon a better bang for the buck? Much longer time at high altitude... sure it's not 100km, but 60km ain't bad
My calculations are assuming that the chambering works at theoretical perfection. Other pushing gases can do better, like light gas. Exactly what reaction you use is up in the air. But I believe there is a pressure-based limit to what gunpowder, for instance, can achieve. Even if you could go higher, there's a major problem with getting the tube itself to withstand higher pressures. This is a good question. I might ask around more about the combustion physics. But to the extent that the pressure upper limit is anywhere around 60k psi, the stated goal on the project page will not be accomplished as far as I can tell.
I am wondering if there is some cheap (freeware) software that can be used for multiple mathematcal simulations? Mathematica may have some in their library; I know HPcalc.org has some
primitive software for trajectory models. There may be a friendly university that would help in the project.
Since it already works, and a measurable degree of success is presented, I would suggest a path for funding. First, determine payload weights in mathematical simulations, from greatist to
unacceptable.(maxima and minima, as x goes to unacceptable). Each payload has rockets, that will assist the fired projectile to reach its target orbit. (this has to be done anyway, for
"seating" in its proper orbit.) The way to achieve funding, is to contract for launching satellites for companies that desire a cheaper way to get their satellite in orbit. Of course, "all you gotta do",
does not apply, as trajectory monitoring apparatus is needed, and probably more system support. ($$) Red Bull Commercial? Great idea, interesting to see where it goes.
That's barely better than my 1975 Citro
The peak increases from 40.0 to 42.5 km.
If you go as low at Cd=0.1, it can work. There are shapes that this would work for, like a perfect aerofoil. But there's another problem - you're at high mach numbers. Some bullet shapes can be as low as 0.1 in the subsonic regime. But the speeds we're talking about are way on the other end. The air flow problem is no longer straightforward fluids, you have to deal with how the shock wave propagates. The work done in HARP is probably the best reference for this.
Have you seen any of the SHARP stuff?
Supercavitation is probably not going to work at supersonic speeds, either.
I do imagine that 45 foot artillery piece will have a MUCH better bang than any wimpie old balloon.