Scrapping Ground Launch Option

The ground launch option contained within Orion would seem an out-dated concept. Excluding the Shuttle experiment, sturdy Russian rockets were able to put aloft a payload of just under 100 tonnes. (Correct me if wrong!). It would be very difficult to envisage how world opinion would tolerate the inevitable radioactive fallout of Orion, and Dyson's book is clear about the problem of rapid radioactive dispersal in the upper reaches of the atmosphere. I think we should also be clear that a test in space with no atmosphere or gravity would produce slightly unpredictable results than a test on ground earth. I would suggest in space all one might see is a temporary torch like beam, not a cloud of dust. The explosive matter would also encounter no resistance in a vacuum or gravitational distortion over time. I am of course a proposer of a tube and pusher-plate (or cannon!) to focus the expansion of the explosive energy. (See other posts). Hence the suggestion of a pencil like torch beam stretching across the heavens, visible from earth as perhaps the familiar shooting stars seen somewhere on earth every day.

If you would ride with me for a moment and accept the "banger inside a cannon" idea, any test on earth would not necessarily produce valuable results. Fracture of the cannon would be more likely on earth and less likely in space. Hence any test on ground earth might merely disprove our ambitions for useful physical containment, when it, up in a space orbit, may prove a success. However saying that, if one could suspend for a moment the harm of fallout, the tube and pusher-plate (or may I now just continue to say cannon? - maybe not) could propel a train or sea boat on earth. I would never really support this because of fallout, but a heavy train on sturdy rails or a big sea boat could be propelled by a nuclear cannon. However in respect to space travel, it is actually a manned atomic space tests we need, not any more earth based ones. The fallout in this case is zero, since provided the cannon is not pointed in a manner to send the emissions in the direction of earth, it would expel debris harmlessly out of our solar system. It is a totally green technology and needs promoted as that. There is the slight possibility that other solar systems might be subject to a contamination pulse, yet space is so vast that the debris would eventually be soaked up by cosmic dust. However astronomers might be consulted on a direction to point the pulse so that it avoided any nearby possible life star systems, as a precaution.

It may seem to the reader that abandoning the ground launch concept of Orion forever limits us to painfully small chemical payload launches. Not so! Everybody knows that a big building site uses cranes to lift heavy objects into position. Hence, once the first cannon is constructed in space and tested successfully, it could then quickly be used to haul thousands of tonnes into space, itself remaining in orbit and never contaminating earth. That is the future. I don't know if it is an "elevator" and I do not instinctively believe any low energy concepts. Hauling stuff into space is an Orion application to the sci-fi concept of the "sky hook", only with plentiful energy being used. I prefer to think of it as a harbour or space tug, pulling heavy weights into space. In terms of the length of cables reaching down from orbit into earth's atmosphere and to the very ground itself, I wouldn't want to debate the ancient paradox "How long is a piece of string?" I am not a materials expert either, but every time I see a new high altitude balloon experiment being successful, I think that this is one more step in the right direction to a system to help support the weight of the cables. I believe at the moment the only proper authority for the ground launch option would be if testing in space failed because the cannon fractured/shattered as a result of its design and it did so too many times to continue testing.

To illustrate the problem I must turn to the ancient Chinese empire and the earlier experiments with gunpowder cannon. The techniques of iron foundries were rudimentary and the bigger cannons had to be forged in several pieces. Until European engineers acquired the alchemical ability to produce high quality gunpowder mixes to test with and improve foundry techniques to cast cannons in one single piece, the cannons were very dangerous to use. Being made from several pieces, bound together with iron rings/hoops it gave them an unwanted tendency to shatter/fracture while in use. This killed the gunners rather than the enemy! The same challenge or problem exists in testing atomic space cannon because of the launch payload of around 100 tonnes. I estimate what is needed is a weight of 500 tonnes of carbon-steel hollow tube and pusher-plate (e.g., cannon), but maybe more, to successfully contain the explosion. That would therefore require assembling in space with the use of astronauts and a space station, but depending on the method of joining the separate pieces to make one cannon, it might produce unsuccessful results. In that way a one-off ground launch option might allow a single 500 or heavier cannon to be constructed, cast in one piece, to be carried aloft and tested. It thus could solve that problem of cannon shattering along the fault lines of the joining segments.

Scrapping Ground Launch Option continued

I never contemplated the ground launch option in my initial theories and my awareness of fallout meant I never considered or wrote about a ground launch option. Hence my earlier conclusion that repeated failures at physical containment in space would have to be abandoned after around 100 test failures. Simply because enough chemical payload failures carrying project material (say 3-5%) would result in increasing radioactive contamination of earth purely as result of these accidents. I named this the HMS Sheffield option after the famous steel town in England during the industrial revolution. That is to then say that mankind could only begin the test again when payload performance maturity and the space industry in general was advanced enough that forging the cannon in space itself would be possible. That is to say in a century we might be advanced enough to construct a space station factory capable of behaving like a steel plant in Sheffield, forging in the furnace the hollow tube and pusher-plate within a near orbit. That would be so expensive and costly, that my knowledge of economic theory prompted me to theorize no further.

However if the ground launch option were a possibility, it would provide a vital alternative to the "HMS Sheffield in space" limit of conceptual advance. However even ignoring the obvious political problems, I am not convinced technically it could work. Not only are there the differences in atmospheric pressure and gravity on earth that I highlight earlier in this post, but the nature of pulse propulsion maybe too unstable to sustain against our gravity. In space the pulses do not have to be very frequent and wrong or not I quickly narrowed my pulse rate down to one explosion per DAY for lack of another figure. Initially I thought RNE, Rapid Nuclear Explosion, rather thinking in seconds. Obviously with a test in space, if successful, the next hurdle would be a sequence of 2 explosions contained in the same direction. The repeat nature would emerge slowly after much testing and reveal unique data on facts of an environment that is so unnatural to our earth based view of physics.

With a ground launch system, especially if it were the first thing attempted as the original Orion concept proposes, it is all very all or nothing. The craft either breaks away out of our gravitational field or it plunges back, and it has used many repeated explosions. If you start the project from aloft to begin with, the issue of repeating and sequencing only becomes an issue after a single cannon shot has been proved a success, and expansion of the test on sequencing rates is gradual. Only the cost of refueling the opposing chemical engines might limit the repeat pattern as it would push the pilot further and further away from earth and increase the traditional juice/chemical propellant required for him to return to a near earth orbit for inspection of the canister/tube and pusher-plate/cannon. Of course a shield would stand between his cockpit and the cannon, and safety issues might make that shield strong enough to protect him even if we were to test an explosion up against the physical containment values of bamboo! I am sure material scientists might suggest sensible materials to test such as ceramic combinations and it could rather be like Edison with his light bulb.