Radiation engines?

[Silvercrest]

Nothing comes to mind. I think if you're looking for an engine that generates thrust from something contained inside the ship, simply emitting radiation out the back will never generate enough oomph to get you anywhere. The solar sail sidesteps that problem because it doesn't generate thrust from inside the ship.

Probably the closest thing to what you want is laser propulsion. http://en.wikipedia.org/wiki/Laser_propulsion There are several ways of doing it, but all of them involve focusing a laser on the ship from somewhere else, and igniting or burning off material that's contained there to generate a reactive force. This has the advantage of not requiring a powerful energy source to be carried aboard the ship and technically it uses "radiation", which light is. However, the radiation does not really push the ship. Ultimately we're still talking about reaction mass being thrown from the ship to push it this way and that. And it's an external source of radiation, just like in a solar sail.

If you want something that is self-contained aboard ship, about the best you can do is an Orion drive. http://en.wikipedia.org/wiki/Orion_drive Basically we're talking about dropping nukes out the back of a (very well-armored) ship and exploding them to propel it. You're getting a lot more bang for your buck (so to speak) than with any sort of fuel, and technically this could be classified as a nuclear engine. Unfortunately this isn't "radiation drive" in the sense you seem to mean, other than there being a severe radiation hazard for anyone nearby. It's still just a reactive force being used to push the ship. For something that's self-contained, there isn't any way around that requirement until we discover some new laws of physics.

 

[KJbushway]

I don't know about that Orion drive. To my knowledge exploding a nuclear weapon in space is dangerous because it emits a EMP, which could shut off power to the shuttle(?) and like you said the radiation.

 

[Silvercrest]

Hey, I didn't say it was a good idea.

 

[Lindley]

Actually, an EMP will only occur in certain conditions in the upper atmosphere. In deep space it would not be a problem.

On the other hand, in deep space the nuke itself would also be less effective because it would not have any medium in which to create a shockwave.

 

[KJbushway]

oh.

 

[CDR6]

oh.

KJ Bushway,

Try searching for NERVA, late 60's - 70's nuke propulsion system. Tested in the desert, the engine actually worked producing low levels of thrust. The original use was, if memory serves, intended for the trip to Mars. Which of course never materialized. (drat!)

-Chuck

 

[sojourner]

NERVA is still not a "radiation engine". It just uses a nuclear generator to superheat whatever you're using for fuel.

 

[Silvercrest]

Unless Kjbushway provides more clarity on what a "radiation engine" is supposed to be, it doesn't matter. We're just throwing stuff at the wall and seeing if he says it sticks. I made my best guesses based on what I think he's saying.

I think KJ at least needs to tell us if he's envisioning something that doesn't require fuel or exhaust. KJ, if you can't tell us that much, then the question is too open-ended to answer.

 

[KJbushway]

I am not looking for a magical answer. Simple inquiry and whats your knowledge on it. Now I know not what I am looking for, an engine that shots a type of radiation out the back sure, Solar Sails sure, Orion sure. I know nothing about it as a whole, sorry but its a broad subject for a reason. If you don't wish to add to it, sorry you feel you can't. Since I know little I can't tell you what is wrong what is right. The reason why I didn't accept solar sails(which I was later corrected on) because I know about that.

 

[Silvercrest]

It's not a matter of knowing what's wrong or right. It's a matter of even knowing what you're asking. "Radiation" and "engine" are just words. If you have no idea what you mean when you throw them out, then you don't have a subject and you're not asking a question. You're trying to get everyone else to identify your subject and question for you. You said "it's" a broad subject, but you can't even say what "it" is.

"I don't know what I'm looking for, but now that a bunch of people have suggested things, I know what I'm not looking for!"

Good luck with that. I can't even figure out how you'll know when you hear the answer you want.

 

[KJbushway]

OK let me try this.
Is there other propulsion out there already developed or in development, that use any type of radiation? I know about solar sails and nuclear types of propulsion.

Does this help any?

 

[Silvercrest]

Sure, a steam locomotive uses heat. That's radiation.

See what I mean about defining your terms?

 

[KJbushway]

I am trying accommodate you. Let me be more clear.

http://en.wikipedia.org/wiki/Radiation
Anyone of those.
Steam engine for outerspace travel, don't know if it has the thrust.

 

[Silvercrest]

OK let me try this.
Is there other propulsion out there already developed or in development, that use any type of radiation? I know about solar sails and nuclear types of propulsion.

I am trying accommodate you. Let me be more clear.

http://en.wikipedia.org/wiki/Radiation
Anyone of those.

Okay, there's one more. The use of an exothermic reaction involving the release of large amounts of infrared radiation. This facilitates the expulsion of reaction mass for propulsion.

 

[sojourner]

Technically, under those terms, any type of lasing device is an "engine". It would just have almost non-existent thrust.

 

[Silvercrest]

Actually, what I described was a rocket engine. I'm trying to make a point here.

 

[Reverend]

Just a wild stab in the dark but is it possible he's thinking of an ion thruster? Of course an ion isn't radiation and it's still generating thrust with a reaction mass but he seams to have a pretty poor grasp of the definition to begin with. Perhaps what he really wants is "blue glowy stuff" that doesn't come from a tank of hydrogen and oxygen? In which case an ion thruster fits the bill.

 

[ProtoAvatar]

Light is subject to Newton's action/reaction force.
This means light emitted from a ship generates thrust. It's just that this 'thrust' is neglijible.
This translates into - radiation engines are useless unless you can generate a 'death ray' of arbitrarily large power.

 

[Ronald Held]

maybe you want a photon rocket, which propels the craft by emitting EM radiation?

 

[Silvercrest]

Let's keep it simple. The exothermic drive as described above is the simplest thing to build, it's proven technology, and it meets his definition.