It looks like the Orion propulsion system using pulse units that use pure fusion as an energy source. If it were staged many times it could have thrust power similar to Orion. It uses particle beams to confine and heat the fusion target so it needs a very good vacuum. Maybe SRBs could lift the ship up to where the atmosphere is thin enough and get the pulse going.
Is this pie in the sky or is this really an Orion with no serious amount of deadly fallout? I wonder of the proliferation problem. Imagine the issue of hydrogen bombs that don't need plutonium or enriched uranium. Terrorism issue? Inevitable anyway?
the reason being: there has, as yet, been no credible fusion energy release in quantities necessary for usable propulsion that has not used a nuclear fission explosive as the preliminary energy source. What does this mean? It means that the the most advanced experiments are tickling the lower edge of break even, but energy amplification has not been credibly achieved. Only nuclear explosives have managed this feat yet.
There are other issues here too: thrust to weight ratio. For credible propulsion, the engine will need to achieve similar thrust levels as an ion thruster which implies a thrust to weight ratio of maybe 1/10000. To date, this has not been achieved at all.
When fusion has yet to be achieved and demonstrated in a laboratory, it really is too soon to discuss propulsion applications beyond vague, theoretical discussions.
Ultimately a spacecraft will need thousands or tens of thousands of newtons of thrust at specific impulse levels in the hundreds of thousands of seconds...this seems to imply gigawatt power levels. A nuclear pulse Orion which has the capability to operationally achieve hundreds of thousands seconds of specific impulse with millions of newtons of thrust: this implies power levels in the thousands of gigawatts. We are presently nowhere near these sustained averaged power levels with anything other than nuclear fission initiated pulse propulsion...
Has anyone seriously thought of staging inertial confinement fusion like the way it is done in very large thermonuclear bombs? The first stage is powered by a laser or other high energy beam and the radiation that produces is channeled into a stage a few times larger than that, which is staged a few times larger, do this about 10 times and you've got a rather unruly explosion instead of just a spark.
I don't think anyone has tried a staged radiation implosion device with laser initiation--but they have tested tiny radiation implosion shells at Lawrence Livermore...all in support of the DOD nuclear testing program.
Radiation implosion is inherently 'lossy'--the reason why it works so well in weapons, is that typically the nuclear 'pump' device (the primary) produces such an abundance of energy that the critical energy density necessary for implosion to work is always achieved...
Lasers or particle beams are just barely at a threshold value--they still cannot supply the high energy densitites necessary to achieve this...but you may have an idea there...
It may be possible to design a terminal optical system that puts enough energy onto a spot of high-z material to create a x-radiating plasma that could be used to fill an almost microscopic teller-ulam radiation bottle...
I think Lawrence Livermore does this on some scale, but almost all of this work is highly classified...
I think Lawrence Livermore does this on some scale, but almost all of this work is highly classified...
This is definately a good thing for now. Terrawatt lasers maybe hard to come by but much easier to make than enriching enough uranium for a bomb I think. Since this could scale to any size.. Could be real bad in the wrong hands.
