Orion, the reality.

[qso1]

Even better. If left to NASA, it may well be yet another technology demonstration excercise. In the hands of a well motivated private investor or company. It has a much better chance of becoming a practical application. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[spacefire]

Like in the novel "Footfall', the Orion is sort of a last resort spaceship. Say you had to deflect an oncoming asteroid or blow up an alien fleet. <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[mlorrey]

How about getting a good number of humans off the planet before everyone destroys each other? That sounds like a last resort to me....

 

[qso1]

There are much less expensive ways to deflect an asteroid and if we don't know what kind of weapons an alien fleet has, how would we know an Orion type craft could destroy an entire alien fleet? <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[nyarlathotep]

>>"How about getting a good number of humans off the planet before everyone destroys each other?"<br /><br />More likely that everyone will be trying to destroy you, in order to prevent the launch.

 

[vogon13]

The 'big' 25 million ton payload interstellar Orion craft envisioned, could only be built and launched in space.<br /><br />Granted, bringing up materials from earth to build such a thing strongly implies smaller earth launch capable Orion supply ships.<br /><br />IIRC, earth launched Orion craft in the />10,000 ton class require nukes smaller than Hiroshima size. Probably the largest Orion craft you would consider for earth surface launch would require nukes under 1 MT. And that would be a very large Orion craft, indeed.<br /><br />Fireball engulfment of the vehicle for the first few detonations till airspeed builds up enough to 'sweep' the efflux behind is considered to be a large problem. However, having the craft in a large balloon made from re-entry ballute material seems to be the answer to that problem.<br /><br />Use of boron in the radiation channel of the propulsion nuke can further reduce the emission into the environment of rad waste from what is already projected to be a relatively (by 1960s standards) clean nuke.<br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[mlorrey]

BTW: Clean nukes are possible, but not built or even published about because the PTB don't want weapons of that power to gain any legitimacy by perceived loss of radiation hazard. The blast still produces a storm of neutrons and EMP.

 

[vogon13]

In the lower atmosphere, IIRC, EMP effects are small up to a few megatons. You are quite right though, at high altitudes, even small nukes can generate annoying (or worse) effects.<br /><br />The boron salted propulsion nuke has virtually no neutron yield, and the largest part of the rad waste are the fission products from the detonation. Advances in the implosion generating high explosive charges allow quite small sub-critical masses to explode now, further reducing the fallout. <br /><br />Additionally, the radiation channel filler material in the propulsion nuke, will absorb gamma radiation and reradiate x-rays. Further, consider the majority of the weapons effects are directed upward at the Orion pusher plate, and not outward or downward into the environment.<br /><br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[rocketman5000]

So basically the whole Orion Class ship would have to be inside a Gausian (or is it faraday) cage to isolate the powersystems of the craft from the EMP?

 

[mlorrey]

Faraday cage, but a metal superstructure already provides that. If you build your cabins from composites, be sure to build wire screen shielding into the fiber mesh.

 

[vogon13]

The pusher plate will reflect quite a bit of the RFI.<br /><br />Additionally, since weight is far less of a concern with Orion than rockets, most of the Orion designs assume submarine construction techniques.<br /><br />Steel.<br /><br />Lots and lots of steel.<br /><br /><br /><br />Sheilding is inherent. Also, as long as the craft is conductive, should gamma rays strip electrons from the craft, as long as the vehicle is at the same potential everywhere, the electrical 'surge' from the nukes will not be a problem. Ever see a helicopter bond to a 500000 volt AC power line for inspections? Same idea.<br /><br />Also, the radiation channel filler material (boron perhaps, or maybe low Z material from the crew, {poo actually}) will absorb gamma rays and re-radiate x-rays. Gamma rays are the big electron zappers, IIRC.<br /><br />{not relavant to Orion, but just as various nuclear effects from an explosion can be attenuated, so to can some effects be enhanced, such as in the case of the microwave bomb. A rather interesting gadget, courtesy of the US military/industrial complex, and as a weapon, pretty much useless against most countries in the world, except our own.}<br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[mlorrey]

I've wondered if anybody has designed a black hole bomb yet. Given that TNT is used to implode plutonium for a fission bomb, and a plutonium bomb is used to implode deuterium for a fusion bomb, and of course a big enough fusion implosion will create a black hole, I've wondered how big a hydrogen bomb one would need to create a mini-black hole. Not one big enough to last, mind you, but one big enough to rapidly undergo matter to energy evaporation as Hawking predicted, converting all of its mass to pure energy. <br /><br />Theoretically speaking, this would convert the 0.01% matter to energy conversion of fusion to 100% conversion, essentially getting the same effects as if you had an anti-matter bomb, so whatever mass of the implosion that you were able to force into an event horizon, would rapidly turn around and be converted into pure energy.<br /><br />I think it goes without saying that this would be a very big explosion, and so far as Orion is concerned, would be a shortcut to interstellar travel, given its huge boost in mass conversion efficiency, equivalent to anti-matter conversion without having the bulky antimatter storage requirements.

 

[chriscdc]

Well not pure energy, you would probably get leptons and stuff, so alot of the mass would be converted into well mass again. Also if it only radiated photons, what energy would they be? They could be so high energy that they would travel out of the 'blast radius' without interacting. This is one of the problems with antimatter energy supplies, you would need a large dense mass of material just to trap the photons emitted.

 

[tomnackid]

Tungsten makes a good trap for photons from an antimatter reaction. The Air Force has been doing a lot of research into solid core antimatter reactors with tungsten as the core material. It is dense enough absorb high energy gamma radiation and convert it to heat. The only problem (well not the ONLY problem, but a major one!) is that you are limited to the melting point of tungsten which, although high, is far below the levels of energy put out by an antimatter reaction, but its a quick and dirty way of getting useful work from antimatter. <br />

 

[mlorrey]

Well, Dyson proposed putting a layer of uranium on the blast plate. Radiation from the explosions would, over time, enrich the uranium layer enough that the vessel could theoretically 'reload' by building new bombs from the enriched material, or use it for powerplants and NTR propulsion for a colony at the destination.<br /><br />The energy (or a large chunk of it) of the quantum black hole evaporation would be absorbed by the plasma of the triggering fission and fusion implosions, so, assuming you converted 1% of the bomb's total mass to energy, versus a fusion bomb converting 0.01% of 5%, or .0005% of the total mass, you'd impart 2000 times more energy to the same bomb ash. Whatever the expected Isp is of a fusion pulse Orion, multiply that by 2000.