Nuclear Pulse Propulsion: Absurd Unscientific Concept?

[DJEN]

One thing that comes to me as absurd is Nuclear Pulse Propulsion. In which you take a Nuclear Shaped Charge and blast it towards a compatible spacecraft's pusher plate/drag sail to create an extreme amount of thrust.

The reasons I regard it as absurd are;

1. Material strength: can the craft's materials endure the nuclear blasts and the acceleration?

2. Ablation of plate/sail: can the plate/sail stay intact long enough?

3. Square/Cube law: can the ship be durable enough?

As Wikipedia did not provide much information regarding these reasons, I'm here to ask of more information.

[Scotius]

Hmmm....would you want to drive your car by repeatedly slamming a wrecking ball into its trunk? Only in this case wrecking ball is actually a full-sized weapon of mass destruction. And your craft essentially is an equivalent of a nuclear arsenal of superpower nation. What can go wrong?

[DonLorenzo]

There's a good BBC documentary about it (and the life of its chief designer/proponent, Freeman Dyson) It's called 'To Mars by a-bomb' and hey! I found it on YouTube

All your questions are addressed and many other interesting things. (In a nutshell, the answer to most are 'surprisingly, yes!')

[shynung]

All of your 3 questions are within the engineering field. With good design, such a ship is possible to be constructed, flown, and used for various purposes.

Problem is, a lot of people object to using repeated nuclear explosions as a means of propulsion. Therefore, the only thing holding relevant developments are political in nature.

[jwenting]

in fact such a ship has been proven in concept. A small scale version HAS been built, using conventional explosives, and tested.

Think it went a few hundred meters up on what were effectively sticks of dynamite.

Beyond that, it's just a matter of scale. And this is probably one area where it gets easier as it gets bigger

[KASASpace]

Okay, here is how it works:

The Orion has a pusher plate at the rear, with shock absorbers, which take the shock and lessen it for the total vehicle.

The ablation problem can be solved by "spraying" a sort of oil over the surface. It prevents the plasma from damaging the plate too much.

The material strength of the craft, if built during the 1960s, might not have been so great.

However, as carbon nanotubes have a large tensile strength, supporting TONS on just 1 millimeter cross-section of wire, it can be done in the not too far off future.

[Nibb31]

Can mods merge this with one of the existing Orion threads? It was fun the first time around, but it starts to get annoying to have to go through the whole discussion for the 15th time.

[KvickFlygarn87]

It's possible, although won't be happening 'til politicians clean up their act. Just because it's nuclear doesn't mean it's bad!

[Rakaydos]

It's possible, although won't be happening 'til politicians clean up their act. Just because it's nuclear doesn't mean it's bad!

Now imagine North Korea with one.

[Nibb31]

It's possible, although won't be happening 'til politicians clean up their act. Just because it's nuclear doesn't mean it's bad!

Sorry, but detonating nuclear bombs in the atmosphere IS bad.

It won't happen in this century or the next, because it's a stupid idea. It would be massively expensive, massively polluting, massively dangerous, and we don't even have the technology or budget to build a useful payload for it.

Again, we've gone over this dozens of times already. Can't you guys just search the forum for the old threads on the subject?

[shynung]

...we don't even have the technology or budget to build a useful payload for it.

If we don't even have a useful payload for something like the SLS, how are we supposed to find one worthy for this?

[Red Iron Crown]

Can mods merge this with one of the existing Orion threads? It was fun the first time around, but it starts to get annoying to have to go through the whole discussion for the 15th time.

The Back button is right there in your browser, no one is forcing you to read or participate.

[Nuke]

Sorry, but detonating nuclear bombs in the atmosphere IS bad.

It won't happen in this century or the next, because it's a stupid idea. It would be massively expensive, massively polluting, massively dangerous, and we don't even have the technology or budget to build a useful payload for it.

Again, we've gone over this dozens of times already. Can't you guys just search the forum for the old threads on the subject?

i imagine orion as something to be built and "fueled" entirely in space. its going to be such a massive ship that ground launching the whole thing would be somewhat impractical. then id put it on an escape trajectory (with chemical propulsion) out of earth orbit and put some distance between it and the earth before detonating the first warhead. this should keep earth and its satellites intact.

[Guest]

I never liked Orion and related "pulse drive" concepts for one reason: inconsistent G load. This would pretty much kill any crewed Orion; dealing with pulsed acceleration for any reasonable amount of time would drive the crew crazy. Even with shock absorbers, you still get a violent jerk whenever you fire up a bomb.

Of course, for unmanned payloads, it'd do just fine. Launch either from the sea, or from a graphite plate that would resist the detonation, so you won't get too much fallout. The enormous payload means not many of those would fly each year.

[Sillychris]

What if we made the bombs a little smaller... and out of D-T pellets?

[Kinglet]

i imagine orion as something to be built and "fueled" entirely in space. its going to be such a massive ship that ground launching the whole thing would be somewhat impractical. then id put it on an escape trajectory (with chemical propulsion) out of earth orbit and put some distance between it and the earth before detonating the first warhead. this should keep earth and its satellites intact.

Ugh. Imagine a Orion refuel craft launch failure.

[Red Iron Crown]

Ugh. Imagine a Orion refuel craft launch failure.

One would have to assume the bombs wouldn't be armed during launch. There have been crashes of planes carrying nuclear weapons before, though nowhere near as many as an Orion refueler would. Definitely an unpleasant thought.

[Scotius]

What if we made the bombs a little smaller... and out of D-T pellets?

You would get something like this: https://en.wikipedia.org/wiki/Nuclear_pulse_propulsion#MSNW_Magneto-Inertial_Fusion_Driven_Rocket

Personally, i like this project a lot more than Orion - it looks and functions more like a real engine, and not disaster waiting to happen.

[Accelerando]

this isn't at all related to the subject matter, but seriously, the title... please don't do this

Subject Matter That I Don't Know A Lot About: Stupid and Impossible? find out more at 11!

this is the lowest form of invitation to discussion

[Kinglet]

One would have to assume the bombs wouldn't be armed during launch. There have been crashes of planes carrying nuclear weapons before, though nowhere near as many as an Orion refueler would. Definitely an unpleasant thought.

Unarmed bombs sill can break into pieces. There is a huge missing chunk of uranium somewhere in the state of eureka.

[Red Iron Crown]

Unarmed bombs sill can break into pieces. There is a huge missing chunk of uranium somewhere in the state of eureka.

Where is the state of Eureka?

[Nibb31]

If we don't even have a useful payload for something like the SLS, how are we supposed to find one worthy for this?

My point exactly. A revolutionary massive interplanetary propulsion system is only usefull if we have massive interplanetary payloads. We don't, and we won't any time soon.

The Back button is right there in your browser, no one is forcing you to read or participate.

It's not about me personally. It's about the dozens of posters who spent time participating actively in posting pro and con arguments about the exact same subject. There has been no magical breakthrough, no sudden change in the laws of physics, so the discussions we had a couple of months ago are still valid.

We can start all over again for the dozenth time, or we can simply point the OP to the existing threads on the subject, such as this one:

http://forum.kerbalspaceprogram.com/threads/60566-To-space-on-nuclear-bombs

i imagine orion as something to be built and "fueled" entirely in space. its going to be such a massive ship that ground launching the whole thing would be somewhat impractical. then id put it on an escape trajectory (with chemical propulsion) out of earth orbit and put some distance between it and the earth before detonating the first warhead. this should keep earth and its satellites intact.

I agree, launching it from the ground would be silly, and the environmental impact of atmospheric nuclear blasts would be terrible.

However, building a kilometer wide pusher plate in orbit is equally impractical. How many billion dollar SLS launches would it take ? How many decades of work to assemble a monolithic part that huge. How many ferry runs to carry the thousands of nukes to orbit, as well as building the hab, bringing up the supplies, etc...

"Wildly impractical" is a euphemism.

[Comrade Jenkens]

I think that a nuclear rocket is a more practical solution than chucking bombs out of the back door.

[Nuke]

Ugh. Imagine a Orion refuel craft launch failure.

mine the fuel from the moon.

I agree, launching it from the ground would be silly, and the environmental impact of atmospheric nuclear blasts would be terrible.

However, building a kilometer wide pusher plate in orbit is equally impractical. How many billion dollar SLS launches would it take ? How many decades of work to assemble a monolithic part that huge. How many ferry runs to carry the thousands of nukes to orbit, as well as building the hab, bringing up the supplies, etc...

"Wildly impractical" is a euphemism.

hell this is either going to be a post infrastructure build for an interstellar colony ship. that or a vessel for an omfgwereallgonnadie type scenario, in which case fallout be damned. this isnt going to be some little one off mission to somewhere for science. either way, this is not something we are ever going to see in our life times. maybe in a thousand years as some sort of backup humanity project. that is of course barring advancements in propulsion that make the concept obsolete. death to the notion of planning on human lifespan scale timeframes. i dont care what is going to happen in the next hundred years, i care whats going to happen in the next million.

you want to build an aircraft carrier right after we just figured out how to build a crude raft? good luck with that.

Edited April 5, 2014 by Nuke

[KASASpace]

My point exactly. A revolutionary massive interplanetary propulsion system is only usefull if we have massive interplanetary payloads. We don't, and we won't any time soon.

NASA proposed, back in the 1960s, as using an Orion as an upper stage. Not as massive as one would think.