Nuclear salt-water rockets! https://en.wikipedia.org/wiki/Nuclear_salt-water_rocket
Powerful, fast, intriguing and disgusting. :)
Nuclear Pulse Propulsion – Orion and Beyond (2000) [pdf]
41–50 of 103 posts
Re: Nuclear Pulse Propulsion – Orion and Beyond (2000) [pdf]
#42Earlier quoted context omitted.
> nuclear is unfashionable at the moment It's more than that - this isn't just hippies, it's every major power on the planet. To fly Orion you have to put hundreds of nuclear explosives in orbit and pinky-swear that you're not going to use them to obliterate your enemies. Nobody is going to accept that. Orion's a fun paper rocket but will never be more. Engineers and they "yay nukes!" crowd will drag it out every cou…
If you read the book (by Freeman Dyson's son) or even the wikipedia page, you'd know the bombs were quite specialized. And it would certainly be possible to allow some verification (the trigger would not need inspection, that would probably be the really sensitive part, from a technology secrets point of view). [Edit: The bombs would be directed, throwing light weight molecules up against the pusher plate.] Also, the…
The "directed" bomb designs used tungsten - in "The Curve of Binding Energy" I seem to remember there is a comment that they were spectacularly good at digging tunnels but I don't know if that was a theoretical prediction or an empirical result.
Re: Nuclear Pulse Propulsion – Orion and Beyond (2000) [pdf]
#43Please read Freeman Dysons's "Disturbing The Universe". This book is autobiographical and Dyson explains his arc of passion for nuclear propulsion and Orion. His strongest statement in this book is some deep respect for a biological scientist who, after seeing declassified army training manuals on chemical and biological warfare, supposedly discouraged the entire western hemisphere from further develomepment. This ki…
>This kind of nuclear research is, thankfully, over. Nuclear pulse propulsion is the only currently viable technology that could be used to make humans an interstellar species. It would also allow us to practically ship up enough materials to build self-sustaining habitats in near space. It is extremely unfortunate that this kind of research is over. Fun fact: the background radiation levels introduced by nuclear pro…
On the other hand if we'd gone all-in on nuclear pulse launchers, there would have been no incentive for companies like SpaceX and Blue Origin to develop reusable conventional rockets which will hopefully achieve the same result at lower environmental and perhaps also financial cost.
Re: Nuclear Pulse Propulsion – Orion and Beyond (2000) [pdf]
#44Earlier quoted context omitted.
If you read the book (by Freeman Dyson's son) or even the wikipedia page, you'd know the bombs were quite specialized. And it would certainly be possible to allow some verification (the trigger would not need inspection, that would probably be the really sensitive part, from a technology secrets point of view). [Edit: The bombs would be directed, throwing light weight molecules up against the pusher plate.] Also, the…
The "directed" bomb designs used tungsten - in "The Curve of Binding Energy" I seem to remember there is a comment that they were spectacularly good at digging tunnels but I don't know if that was a theoretical prediction or an empirical result.
I meant that the material thrown at the plate were planned to be plasma of more lightweight materials, iirc. (That is different than how to make an atomic bomb directed.)
I haven't seen any real details of directed bomb design discussed. Thanks for the pointer to that book.
Re: Nuclear Pulse Propulsion – Orion and Beyond (2000) [pdf]
#45Earlier quoted context omitted.
Exactly - i think there should be more companies & organizations working towards pushing this. To become space-faring, we need to get from 1ev per bond of molecule level of energies obtained from chemical to 1GeV levels atleast!
We are a long ways from becoming space faring. For the cost of sending one human to Mars, we could send ten rovers to Mars.
Not if Elon Musk gets his way. If the cost profile works out, sending a human will be cheaper then sending a robot.
Re: Nuclear Pulse Propulsion – Orion and Beyond (2000) [pdf]
#46Happy to see this getting some attention. It's seemed like one of the only viable propulsion methods for interstellar purposes, though nuclear is unfashionable at the moment. I remember seeing a chart showing that it was possible to reach other stars using a technique like this. Unfortunately the problem is slowing down. You could get there, but you'd be going too fast to stop. And since the more fuel you carry, the…
> nuclear is unfashionable at the moment It's more than that - this isn't just hippies, it's every major power on the planet. To fly Orion you have to put hundreds of nuclear explosives in orbit and pinky-swear that you're not going to use them to obliterate your enemies. Nobody is going to accept that. Orion's a fun paper rocket but will never be more. Engineers and they "yay nukes!" crowd will drag it out every cou…
> To fly Orion you have to put hundreds of nuclear explosives in orbit and pinky-swear that you're not going to use them to obliterate your enemies.
To reiterate berntb's point: Every nation who has the ability to do this already has ICBMs that can deliver nukes anywhere on the planet in 20 minutes. So what difference does this make?
Re: Nuclear Pulse Propulsion – Orion and Beyond (2000) [pdf]
#47Earlier quoted context omitted.
> nuclear is unfashionable at the moment It's more than that - this isn't just hippies, it's every major power on the planet. To fly Orion you have to put hundreds of nuclear explosives in orbit and pinky-swear that you're not going to use them to obliterate your enemies. Nobody is going to accept that. Orion's a fun paper rocket but will never be more. Engineers and they "yay nukes!" crowd will drag it out every cou…
> To fly Orion you have to put hundreds of nuclear explosives in orbit and pinky-swear that you're not going to use them to obliterate your enemies. To reiterate berntb's point: Every nation who has the ability to do this already has ICBMs that can deliver nukes anywhere on the planet in 20 minutes. So what difference does this make?
True, but we still have a treaty that prohibits bombs in orbit, because they'd reduce the warning time enough to threaten deterrence.
Maybe one day we can launch Orion from Mars.
Re: Nuclear Pulse Propulsion – Orion and Beyond (2000) [pdf]
#48Earlier quoted context omitted.
We are a long ways from becoming space faring. For the cost of sending one human to Mars, we could send ten rovers to Mars.
Not if Elon Musk gets his way. If the cost profile works out, sending a human will be cheaper then sending a robot.
His cost estimates depend on hundreds of thousands of people signing up, to diffuse R&D costs. That's dubious.
Historically, colonists are self-interested. Typically they want to become rich, or they want to escape poverty or persecution. (Typically they're also poorly informed about just how dangerous their new life will be, and how much wealth they can expect to find, but in this age we shouldn't expect that to last much beyond the first landing). There's no precedent that I'm aware of for people leaving comfortable, privileged lives in mass to colonize someplace that has no wealth.
Re: Nuclear Pulse Propulsion – Orion and Beyond (2000) [pdf]
#49Earlier quoted context omitted.
Sort of like a sailboat, except the wind is the vaporized material from the nuke. The nuke explodes, throwing a ton of mass and energy in every direction. The rocket uses a sail or pusher plate to catch part of that mass and energy, which carries it forward.
The mass is pretty tiny ( smaller than the ejected fuel pellet); I presume it's the fact it has huge velocity, hence huge momentum? What about photons; do they have the same effect as other particles, or is there a different effect?
You add a significant amount of mass to the bombs to act as propellant. I don't know offhand what fraction is typical for Orion designs.
Re: Nuclear Pulse Propulsion – Orion and Beyond (2000) [pdf]
#50I think I like the recent work on pulsed fission-fusion better. Basically you have a normal z-pinch fusion system but surround the fusing hydrogen with U238. It absorbs the fast neutrons from the fusion, fissions, and creates more heat driving the fusion. There's some radioactive waste flying out the nozzle but if you're already in space that's not a huge problem.
On the upside, people aren't going to get nervous about nuclear weapons in space since you can't trigger the fuel pellets outside the engine. And you don't need a massive pusher plate, you just direct the charged plasma with magnetic fields. And that means you can wait to turn this on until you're in orbit and avoid creating any fallout on Earth.
https://www.nasa.gov/content/pulsed-fission-fusion-puff-prop...