Space Cannon: Groobles incredible dream

[grooble]

Hi, my goal is to build a cannon that launches payloads into space so cheaply, that it will revolutionise our space capability. The time line is 20 years, by the end of which i hope to be able to launch dozens of payloads per day which can land on the moon, or more advanced payloads that can travel to mars.<br /><br />I intend to build on the dreams and history of the idea, which stretches back to Jules Vernes Pump Gun cannon in his 1865 novel: From the Earth to the Moon.<br /><br />Just check out what was capable in 1918!<br /><br />"The Paris Gun fired a 106 kilogram shell, driven by an explosive charge of 200 kilograms that produced an acceleration of 7,500 gees and a muzzle velocity of almost 6,000 kilometers per hour."<br /><br />Please note, never in a million years would i expect to use this to launch humans, it'd purely be a payload gun.<br /><br />Humans can go up on rockets, shuttles and space planes.<br /><br />"Oberth and Valier did their homework and their space gun was technically plausible. However, it was clearly a monstrously expensive proposition and it is unlikely that even they thought it would be built any time soon. And there is where matters stood, until Gerald Bull entered the scene a generation later. "<br /><br />

 

[grooble]

"On 19 November 1966, the HARP supergun blasted a Martlet 2 to an altitude of <b>180 kilometers.</b> This record still stands as the highest launch of an artillery projectile. "<br /><br />That's 80% higher than spaceshipone flew folks.

 

[mikejz]

Yeap<br /><br />AFAIK the real issue with a space gun is figuring out what payloads can actually be fired given the stresses of launch (or should i say fire). Also, building a 2nd stage that can withstand the same forces.

 

[grooble]

Some of the shells could withstand 10,000 gees.

 

[mikejz]

True, but the question is what usable payload could withstand those forces?

 

[grooble]

Yeah, you'd need some good dampening to keep the payloads in one peice. I was thinking just raw materials, water, metals, grains. The shells themself would be a whole area of research, constantly refined.

 

[yevaud]

Gerald Bull's Advanced Metals corp. (the designer and maker of HARP) designed a few "SuperGuns" that could either place a 1-ton payload into LEO, or fire the same shell at targets 5,000 nautical miles downrange. <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>

 

[grooble]

Yep, i've read a bit about Bull. If he was still alive imagine the cannons we'd have today? Then there is the SHARP cannon, light gas. That went defunct in 93, lack of money as usual.<br /><br />"Excerpted from: “The SHARP Gas Gun: Shooting Payloads into Space Jules Verne’s Way,” Energy & Technology Review, Lawrence Livermore National Laboratory, July 1993.)<br /><br />We are attempting to do in reality what Jules Verne imagined and then described in his 1870 science fiction work, From the Earth to the Moon. Verne fired his spaceship at the moon from the barrel of a huge gun (a larger version of the cannons from which those circus daredevils, the human cannonballs, are shot.) We want to send a payload into low-Earth orbit from the launch tube of a gas gun. <br /><br />For more than 25 years, gas guns have been used to launch projectiles to velocities as high as 11 km/s or 25,000 mph (in this case, the projectiles were the size of 22-caliber bullets and weighed only a fraction of a gram). Gas guns are very useful for equation-of-state experiments, which require high projectile velocities. In these experiments, we use a gas gun to fire projectiles into a target material—metal, fluid, gas, plastic, rock, etc.—in order to subject the material to extreme and dynamic conditions of pressure, density, and temperature. The impact of the projectile creates a controlled and reproducible environment in which we can measure the materials’s response to these conditions, determine its properties, and predict its behavior. The physics of gas guns is well understood, and thus they can be scaled up to make very large systems. Our Super High Altitude Research Project (SHARP) is a two-stage hydrogen gas gun that is basically a very large and sophisticated version of a compressed-air, or B-B, gun. <br /><br />Although the current SHARP gas gun is scaled for experiments rather than for delivering payloads into orbit (it is much smaller than the final launchers will be), it is probably the la

 

[yevaud]

The Germans had a WWII equivalent, called the HPP (High Pressure Pump) gun, which was based at Mimoyeques on the English Channel. They actually used it a few times. It could apparently launch shells that would hit London. <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>

 

[grooble]

Yeah they were building it in Paris, it'd have fired shells across the channel. Luckily the allies realised the germans were up to something and bombed it.<br /><br />Above: (These studies are important because we must be able to design payload containers that don’t burn up in the atmosphere on their way into orbit.) <br /><br />Easy, coat it with fire paste. Problem solved. Also you could put another layer of protection over the fire paste, by the time it burnt through the shell would be out of the atmosphere and contents intact.

 

[spacester]

<font color="yellow">. . . "SuperGuns" that could either place a 1-ton payload into LEO . . . </font><br /><br />Nope, nuh-uh, can't work.<br /><br />Hey I like new ideas, but the laws of physics must be accounted for, doncha think?<br /><br />A projectile fired from the surface of any planet or moon will do one of two things. Period. There is no in-between result.<br /><br />One, it has enough velocity to escape the planet's gravitational field entirely, or . . .<br /><br />Two, it will return to the surface of the planet.<br /><br />This is why a second stage is required. A simple projectile cannot re-direct its velocity vector, and that's what you need to do to achieve orbit.<br /><br />There have been multiple threads on this subject; it would behoove you to check them out and learn about the realities involved. I get the impression you haven't. <div class="Discussion_UserSignature"> </div>

 

[yevaud]

That's correct, I have not. Please scroll up about 2-3 posts, and you'll notice that I'm relating what Gerald Bull's co. said. Didn't say I bought it.<br /><br />I might add that they never described any of the parameters of their design, and I wouldn't have expected them to. For all I know, they had a shell with flapping wings.<br /><br />Please try to not read things into what people have <b>not</b> said. <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>

 

[grooble]

I already know bout second stages, that's what Bull was working on, rocket assist, before he was assassinated. <br /><br />"Bull's Babylon supergun was to weigh 1,900 tonnes and was to be 156 meters long, with the barrel built in segments and supported by four huge shock absorbers. The tube walls would be 30 centimeters thick at the base, tapering to 6.5 centimeters at the muzzle. It would have a bore of a full meter, and would be capable of launching a two-tonne discarding-sabot rocket projectile, an evolved descendant of the Martlet 4, that could put a <b>200 kilogram payload into orbit. </b>"<br />

 

[mrmorris]

<font color="yellow">"Please try to not read things into what people have not said"</font><br /><br />This might have been more appropriate if he was replying to you. Since he was replying to a post by grooble... it's just a wee bit... ironic. <img src="/images/icons/smile.gif" />

 

[spacester]

<img src="/images/icons/laugh.gif" /> <div class="Discussion_UserSignature"> </div>

 

[yevaud]

MrMorris:<br /><br />As I was the one who said about the "placing the 1-ton shell into orbit," it was a natural assumption. And he quoted it.<br /><br />Besides, I'm only trying to place this into context, not indulge in a flame war. <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>

 

[grooble]

Well spacester was wrong.

 

[mrmorris]

<font color="yellow">"... it was a natural assumption"</font><br /><br />Yep -- those old assumptions. Generally though, I assume that 'replies' are directed at the post for which one has hit 'reply' to. Considering the post being replied to was also one by grooble -- who originated and is the primary proponent of this thread and is indicating (presumably seriously) that he intends to build sucha cannon... this would seem to be fairly good corroborating evidence that the text of the reply was indeed intended for him. From this -- your fairly strong reaction -- and especially your admonishment about not reading things into what people say seems... well I've already used the word 'ironic' once.

 

[grooble]

Here is a video clip of the SHARP cannon firing in 92/93:<br /><br />http://www.llnl.gov/timeline/1990s/Movies/sharpgun.mov<br /><br />It's in quicktime format.<br /><br />

 

[yevaud]

You can't simultaneously engage into a discussion and discuss the ins and outs, all the while being told that you're accountable for everything left unsaid. My mistake. I wasn't implying anything one way or another.<br /><br />MrMorris: an addendum, if you happen to read this. You might note that the quoted line was "..."superguns," which can place a 1-ton shell into LEO."<br /><br />You might note that the reason I responded to it is that's a <b>direct quote from my prior post. No one else's.</b> Speaking of "getting one's facts straight."<br /><br />Yes, it <b>is</b> ironic... <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>

 

[spacester]

<font color="yellow">Well spacester was wrong.</font><br /><br />Would you care to elaborate?<br /><br />I just reviewed the thread. There is no indication in any of your posts (prior to my first post) that you were aware of the need for a second stage. Everything refers to 'projectiles' and 'shells' and 'payload containers'. This is in spite of a detailed description of the gun itself.<br /><br />So I was wrong to say "I get the impression you haven't"?<br /><br />Or was I wrong to point out the physics? (I <i>know</i> I'm right about the physics).<br /><br />Or was I wrong to rain on your parade in the first place?<br /><br />What you should realize, grooble, is that I try to engage in crontructive criticism. I would love to see you achieve your dream. In fact just today on another thread I was pointing out that there are alternative ways of getting payload (propellant) to LEO and some may be much cheaper than traditional staged rockets.<br /><br />But without a basic grounding in physics, you will not achieve your dream.<br /><br />I cannot know what you don't know, but I can make a judgement, a guess, based on what you <b>do</b> say. <div class="Discussion_UserSignature"> </div>

 

[grooble]

In saying:<br /><br /> . . "SuperGuns" that could either place a 1-ton payload into LEO . . . <br /><br />Nope, nuh-uh, can't work. <br /><br />---<br /><br />They could work with rockets. I thought you meant it couldn't be done at all. Don't worry bout it. I don't know all the facts, i'm reading what i can find about super cannons and similar constructs. It can definatly be done, i'm curious as to what could be possible with today's tech, like Morris and his thread. I'm not as technical minded as Morris, but i'm still gonna try.<br /><br />Also the aim isn't really orbit, but for the shells to land on the moon, somehow.

 

[spacester]

<img src="/images/icons/cool.gif" /><br /><br /><font color="yellow">They could work with rockets.</font><br /><br />It's possible. A major problem is the incredible acceleration and what it would do to the second stage's rocket engines and other systems. That's why I wanted to be sure you understood that a second stage is needed: IMO that's as big a problem as the gun itself.<br /><br />Of course, the other major problem is air resistance. It's a really really big drag; basically you cannot leave the muzzle fast enough without burning up in seconds.<br /><br />So IMO you're looking at 'assisted launch' - leave the muzzle as fast as you can without burning up. That can reduce your required velocity gain enough to use a 'SSTO' rocket with much higher payload than without the assist from the gun.<br /><br />Another strategy to consider is not using rockets on your projectile, but somehow have a 'space tug' rendezvous with it and finish the journey to LEO that way. This is very difficult, but not impossible.<br /><br />I like the idea of going straight to the moon somehow, but boy oh boy it's not gonna be easy. <div class="Discussion_UserSignature"> </div>

 

[scottb50]

I concur.... a SSTO vehicle launched on a maglev rail, reminicient of the rocket ship in the the 1951 movie When Worlds Collide. .....<br /><br />If you look at the cost and complexity of such a system, compared to the savings it just doesn't add up. The choice is a huge amount of infrastructure or added mass at lift-off, vertical launch is the best solution, at least for large payloads. <div class="Discussion_UserSignature"> </div>

 

[nexium]

Hi grooble: 1900 tones is about right for the dimensions. Two tons is light for a rocket projectile that can survive 1/10 th second at 6000 g unless the rocket projectle is less than two meters long.<br /> V= at = 6000 times 32 times 0.1 = 19,200 feet per second = 13,000 miles per hour. The pay load needs to survive nearly all of the 6000 g which excludes a lot of things.<br /> I don't think fire paste is adequite for 13,000 miles per hour, nor 6000 g, even if the Babylon is five miles above sealevel. Excreating water though porus metal however might prevent the projectle skin from vaporizing. <br /> We could perhaps use 3000 g, 6500 miles per hour, but I think the rocket projectle would need to be much larger to put 200 kilograms in a circular orbit 200 miles up. Neil