Thread: Rifle shot payloads to space?

Here is an idea:

Why do we not dig deep shaft-like holes into the Earth, place explosives at strategic locations within the shaft, add the payload and detonate in sequence the explosives to provide a thrust sufficient enough to "shoot" the payload into orbit?

I'm thinking like if you have a rifle and the barrel is this shaft, the bullet is the payload and the gun powder is the explosive...

Would this be impossible? Would the required depth of the shaft be just too great? If yes, could we not have the shaft at less of an incline and then slowly increase the incline so that we wouldn't need to dig so deep?

What do you guys/girls think?

Rich.

I don't think explosives would be your best bet, as too much energy would go radially instead of toward space, but exploration of doing it with something like a railgun has been in the works for years. Here's an article from about 9 months ago:

http://www.universetoday.com/73536/n...-to-the-stars/

Originally Posted by inow

I don't think explosives would be your best bet, as too much energy would go radially instead of toward space, but exploration of doing it with something like a railgun has been in the works for years. Here's an article from about 9 months ago:

http://www.universetoday.com/73536/n...-to-the-stars/

Awesome thanks, this is similar - but I am thinking more underground and have speeds increased continuously until above ground so that the cargo could be lighter(less fuel required as it's all ground based). Also, I was thinking this would be more aimed toward payloads such as satellites and other cargo, as opposed to crew.

I would like to see some more thoughts on this idea

I'm no physicist, but I don't think you would get sufficient force to launch a payload into space from a cave without using so much explosives that it would destroy it. The link provided above should be a better alternative.

Jules verne once wrote a book called from the earth to the moon, in which the voyagers were launched in a giant projectile. In reality the g-forces would have killed them. Only sturdy cargo could launch on such a vehicle, and you would need far more explosive in the cannon than you would if you just built a rocket.

IIRC, there was (briefly) plans to use a, underground nuke to launch stuff into space (thousands of tons of stuff at a time, very cheaply). Of course, no one actually tested it.

I'm not talking about launching people into space with this method... I am talking about launching cargo. By building a tube underground with a slight incline and detonating explosives at a timed interval, we could generate enough motion for the payload to be projected into orbit, just like if you were to fire a bullet from a gun.

Originally Posted by Rickz2020

I'm not talking about launching people into space with this method... I am talking about launching cargo. By building a tube underground with a slight incline and detonating explosives at a timed interval, we could generate enough motion for the payload to be projected into orbit, just like if you were to fire a bullet from a gun.

A gun launch will destroy all but the most specifically hardened packages -- and that includes all of the communication satellites and scientific packages. The only electronics that have been built to survive gun launch are guidance packages for guided munitions.

This is done without detonating explosives, gun propellants deflagrate. If your plan includes detonating explosives you will destroy the vehicle, the payload, and the tube.

I siggest that you stick with technologies that you understand.

Ok fine, perhaps explosive is not the solution, but I'm sure there is another material that could be used.

I'm not suggesting exposing naked components to the blast... Obviously all the payload contents will be inside a robust and shielded capsule. Also, obviously the tube will be strong enough to withstand the blasts, just as the capsule would have to be.

By the way, why is it that communication satellites and whatnot would be destroyed? I'm not suggesting a huge blast detonated against naked components - I'm suggesting a slow increase of speed using explosives (or perhaps something else) to gradually bring the payload to a speed sufficient enough to achieve orbit.

Originally Posted by Rickz2020

By the way, why is it that communication satellites and whatnot would be destroyed? I'm not suggesting a huge blast detonated against naked components - I'm suggesting a slow increase of speed using explosives (or perhaps something else) to gradually bring the payload to a speed sufficient enough to achieve orbit.

You have just described a rocket.

Another point of interest, if you launch an object at ground level with sufficient speed to retain orbital velocity by the time it reaches orbital height, you will wind up with a vaporized projectile. I don't care what you make it out of.

MW

@Rickz, the problem isn't the explosion itself, it's the g-load generated. Just because it's not a person doesn't mean high g-forces can't hurt it. You can squish electronics too (or more often, pull something important loose).

Also, see Project Orion.

Originally Posted by Rickz2020

Ok fine, perhaps explosive is not the solution, but I'm sure there is another material that could be used.

I'm not suggesting exposing naked components to the blast... Obviously all the payload contents will be inside a robust and shielded capsule. Also, obviously the tube will be strong enough to withstand the blasts, just as the capsule would have to be.

By the way, why is it that communication satellites and whatnot would be destroyed? I'm not suggesting a huge blast detonated against naked components - I'm suggesting a slow increase of speed using explosives (or perhaps something else) to gradually bring the payload to a speed sufficient enough to achieve orbit.

http://en.wikipedia.org/wiki/Space_gun

I found something that is basically what I am thinking of. Check it out if you are interested. There is a video lecture towards the bottom.

http://www.physorg.com/news183023838.html

Originally Posted by Rickz2020

I found something that is basically what I am thinking of. Check it out if you are interested. There is a video lecture towards the bottom.

http://www.physorg.com/news183023838.html

450kg is a very small payload

5000 g is an enormous g-load (ICBMs are limited to about 12 g and space launchers to less). Payloaders worry about much much smaller shock and acoustic loads. 5000 g is beyond the pale.

Even 5000 g on "rocket fuel" would be a problem, depending on the fuel and its packaging. Gun launching rockets is a specialized engineering task. Very specialized.

MeteorWayne's vaporization is a bit of an exaggeration, but the aeroheating would be severe and the weight of insulation would reduce the already small 450g payload.

There would have to be an on-board propulsion system for orbit shaping, and/or terminal maneuvers. Hardening a propulsion system against gun launch loads is possible, but very specialized and not cheap.

By shooting a space vehicle from such a tube, the max q (maximum aerodynamic pressure against the projectile due to its movement through the atmosphere) would occur at the "muzzle" for two reasons: the velocity is the greatest at the muzzle, and the atmosphere is the densest at the earth's surface. The projectile would "coast" for the remainder of the flight, so we're talking about high muzzle velocities and aerodynamic pressures along with very long barrels.

It would require very high barrel pressures. I also envision possible shock waves reverberating up and down the tube. How could they be minimized?

Other ideas not normally applied to space rockets include using sabots, having the base of the rocket aerodynamically shaped (like a javelin), and using base bleed technology.

This is my thread on the very similar porblem
http://www.thescienceforum.com/viewt...er=asc&start=0