/sci/ - Science & Math

[Anonymous No.12482384]

Is it possible to build nuclear-powered rocket engine?

[Anonymous No.12482389]

>>12482384
Not only is possible, is necessary and essential

https://youtu.be/U1g2aSj9ZTc

[Anonymous No.12482399]

>>12482389
I meant the use of engines that solely use energy of nuclear fission, not heating up and expanding some other propellant. Like a reaction in nuclear bomb, but much slower and more controllable.

[Anonymous No.12482420]

>>12482399
Rocket engines by definition use propellant.

[Anonymous No.12482423]

>>12482420
Ok then.

[Anonymous No.12482428]

>>12482399
How would you reconcile such an idea with conservation of momentum?

[Anonymous No.12482446]

What you're looking for is Project Orion:
https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion)

[Anonymous No.12482452]

>>12482428
I am actually a bit retarded when it comes to physics, but is it possible to use elementary particles, that nuclear fission crreates to propulse the ship? Sort of the same mechanism as in ion engines.

[Anonymous No.12482458]

>>12482452
no that is not possible. the way nuclear energy works is they put a rock in a pool which slowly heats the water. youre not going to get propulsion out of that

[Anonymous No.12482465]

>>12482458
Thanks for clearing up my misconceptions. But I am also wondering, how effective are ion engines compared to chemical rockets?

[Anonymous No.12482492]

>>12482465
ion engines are only useful in vacuums (space). they are ass tier otherwise

[Anonymous No.12482509]

>>12482458
Gamma radiation, neutron stream or heat can be used to give impulse to the starship.
But efficency of that engine would be pretty low.
Maybe it could be used in space probes, I think.

[Anonymous No.12482513]

>>12482492
>>12482509
>>12482465
Then I guess, that we will be able across the entire solar system only when we will find a way to cheaply produce antimatter. Other options suck ass.

[Anonymous No.12482588]

>>12482384
This is Ulam's nuclear pulse propulsion, that is, H-bombs as a rocket propellant. The plasma and x-rays of an H-bomb explosion is an incredible rocket, due to the enormous temperatures and ablation pressures, and this impulse can be concentrated and directed onto a large plate.

This design is so much more efficient than other designs that there is no comparison. It's like winding up a car with a spring versus filling it with gas. There is no other way to achieve such a huge amount of thrust cheaply.

The drawback to this is that the bombs generate a certain amount of atmospheric fallout on takeoff. This is some hundreds of low-yeild atmospheric atomic explosions, and even with the cleanest designs, it will not be a negligible amount of pollution. With research, it might be possible to reduce the fallout levels, this research was not popular during the cold war, small clean nuclear bombs made nuclear war more likely. There is probably a potential for bombs that produce largely short half-life fallout of elements which are not likely to concentrate in living things. The total fallout should be less than recent accidental disasters, but it will be comparable.

If you allow a government to build such a rocket, then you can just build the base on Earth, make it a 10,000 ton rocket, and blast the whole thing to Mars, then return the folks that go along on a smaller Orion rocket included in the base, that they wheel far away and blast off in. There is really none of the standard weight limitations here, the rockets are easier to engineer the bigger they get, with the caveat that the larger the rocket the greater the total cumulative fallout on takeoff.

This is so much cheaper than any other method (at least, any other method that fully shields the astronauts from radiation during the journey). There probably are no other realistic methods, this is a difficult problem, and the number of solutions to difficult problems is usually either exactly 0 or exactly 1.

[Anonymous No.12482594]

>>12482588
just build it in orbit, forget about taking off with nukes, propelling yourself in space faaar far away from earth? maybe if you manage to convince the world

[Anonymous No.12482607]

>>12482399
Nuclear salt water engine

Take nuclear salts
Dissolve in water
store in moderating tank
release into chamber without moderator
salt water goes critical
explosion vaporizes steam and exhaust leaves through nozzle
A rocket powered by a continuous nuclear explosion/water dissolving into a plasma

[Anonymous No.12482642]

>>12482509
How would you direct gamma rays and neutrons? The radiation produced in a nuclear engine is isotropic, you can't extract thrust from it.

[Anonymous No.12482765]

>>12482642
Make hole facing needed direction?
I don't know much about reactors, thought that there are anisotropic reactors.

[Anonymous No.12482902]

>>12482458
Yes, it is.

>>12482452
check this out.

https://en.wikipedia.org/wiki/Fission-fragment_rocket

A fission fragment rocket is basically a radioisotope that is shielded all around except for the "exhaust bell"... the fission fragments (results of fission) spray out the back at a VERY high velocity, causing some truely impressive specific impulse (about 1,000,000 seconds)

the only problem is that it is incredibly low thrust... and the engine is really heavy.

http://www.projectrho.com/public_html/rocket/enginelist2.php#fissionfragment

technically, we can make this with today's technology, it's just that for basically all mission profiles, it's easier and cheaper to use some other form of propulsion.

[Anonymous No.12482906]

>>12482399
Smaller pellets. Proper fission measurements. New isotopes.
Also, you could just increase the net spread of the impact over a larger surface, in layers.

[Anonymous No.12482916]

>>12482588
>There probably are no other realistic methods, this is a difficult problem, and the number of solutions to difficult problems is usually either exactly 0 or exactly 1.
A launch loop can be built with current technology and materials science, and would allow for massively cheaper orbital launch costs than conventional rockets - the only problem is the investment cost and finding somewhere to build the damn thing.

[Anonymous No.12482975]

>>12482916
launch loops are unstable and no way to stabilize them has been tested.