# New Nuclear Engine Could Power Deep-Space Exploration



## micropage7 (Nov 29, 2012)

_A proposed deep-space probe to Jupiter that uses the radioactive nuclear engine proposed at NASA and Los Alamos._

Researchers have tested a small prototype of a nuclear-reactor engine design that could one day power deep-space exploration probes.

The proposed design is based on a Stirling engine – an engine first invented in the 19th century that uses hot pressurized gas to push a piston. It would use a 50-pound nuclear uranium battery to generate heat that is then carried to eight Stirling engines to produce about 500 watts of power.

Scientists at NASA’s Glenn Research Center and Los Alamos National Laboratory have tested a pared-down prototype of this design using a small nuclear source and a single Stirling engine that produced about 24 watts of energy. Most deep-space probes require about 600 to 700 watts of power, so it will still be a while before this early test produces something capable of powering a spacecraft. This is the first test of a nuclear reactor system to power a spacecraft conducted in the U.S. since 1965.

Nuclear engines are important because they make possible exploration of the entire solar system. Beyond Mars, sunlight is so weak that solar panels would have to be football-field-sized in order to eke out enough power to run a spacecraft and transmit data back to Earth.

For the last few decades, NASA has used plutonium-238 to power its deep-space probes, including the Voyager spacecrafts and the Cassini mission currently in orbit around Saturn. But beginning in the early 1980s, the U.S. began decommissioning its plutonium production sites and by 1992 had no way to generate new plutionium-238. NASA’s Curiosity rover, which is right now driving around Mars, carried some of the last bits of American plutonium with it to the Red Planet.

In 2011, NASA and the Department of Energy received about $10 million to restart plutonium production, and should soon be capable of generating a few pounds of the material each year. This tiny amount will be highly coveted for deep-space missions. A nuclear Stirling engine that generates electricity using more-abundant uranium would reduce the demand for plutonium-238.

If they are created, such reactors would help keep scientists busy exploring the giant outer planets and all their moons for decades to come. Stirling engines could also be used to power a robotic probe on Venus, generating enough power to keep the machine cool in the midst of the planet’s hellish surface temperatures.

http://www.wired.com/wiredscience/2012/11/radioactive-stirling-engine-exploration


----------



## caleb (Nov 29, 2012)

Isn't the mars bot nuke powered too ?


----------



## Frick (Nov 29, 2012)

Forget about space, where is my nuclear powered car??


----------



## ALMOSTunseen (Nov 29, 2012)

caleb said:


> Isn't the mars bot nuke powered too ?


Yah, got this little cylinder Reactor hanging on the side of it.


----------



## lyndonguitar (Nov 29, 2012)

still waiting for the hyperdrive


----------



## ALMOSTunseen (Nov 29, 2012)

Frick said:


> Forget about space, where is my nuclear powered car??


Forget about brain cells, where is my nuclear powered car?


----------



## FordGT90Concept (Nov 29, 2012)

I think steam turbines are more efficient at generating electricity than steam pistons.  It's also substantially lighter.  Seems silly to use an inferior, older technology unless they require lots of torque for something.


----------



## Aquinus (Nov 29, 2012)

FordGT90Concept said:


> I think steam turbines are more efficient at generating electricity than steam pistons.  It's also substantially lighter.  Seems silly to use an inferior, older technology unless they require lots of torque for something.



If you already have rotational motion you could use it to change the pitch, yaw, and roll of a probe without the need of too much additional hardware that way you don't need to use electric motors instead leaving more power for other things.


----------



## nt300 (Nov 29, 2012)

FordGT90Concept said:


> I think steam turbines are more efficient at generating electricity than steam pistons.  It's also substantially lighter.  Seems silly to use an inferior, older technology unless they *require lots of torque* for something.


They do require lots of torque. 
This s old news. Remember the Orion Project 45+ years ago? If they continued with that project man would be in deep space right now. This was suppose to travel between 19km to 31km per second 



> The Orion concept offered high thrust and high specific impulse, or propellant efficiency, at the same time. The unprecedented extreme power requirements for doing so would be met by nuclear explosions, of such power relative to the vehicle's mass as to be survived only by using external detonations without attempting to contain them in internal structure.........


----------



## Frick (Nov 29, 2012)

ALMOSTunseen said:


> Forget about brain cells, where is my nuclear powered car?



Hey would you say no to this?


----------



## FordGT90Concept (Nov 29, 2012)

Aquinus said:


> If you already have rotational motion you could use it to change the pitch, yaw, and roll of a probe without the need of too much additional hardware that way you don't need to use electric motors instead leaving more power for other things.


Steam turbines only act on one axis.




nt300 said:


> They do require lots of torque.


For?


----------



## Steevo (Nov 29, 2012)

Torque is the 90 deg offset of the rotation of spin. 

How do you think they use gyroscopes to reorient space craft in flight requiring no propellant?

Also why do you think we don't use high power turbines in space? The mass difference between the housing and turbine shaft would determine the acceleration rate difference (delta) between the two objects. So if the turbine is throttled up and has 1/100 the mass the shuttle would then spin not at 1% the RPM of the change, but at a value based on the leverages of mass and placement of the engine. So it would start to spin on two axis instead of just the opposite direction, making it harder to control.

https://webspace.yale.edu/chem125/125/spectroscopy/nmr/Precession/precession.htm


----------



## FordGT90Concept (Nov 29, 2012)

You can make a turbine that has masses spinning clockwise and counter-clockwise simutaneously so it is rotationally neutral.

As for making the craft reorient itself, electric servos would be better for that.  They consume no power when idle.


----------



## Steevo (Nov 29, 2012)

More parts, more chances for failure. Unlike even an aircraft where if an engine fails they still land safely in an hour, in space, and months away from home would you rather suffer a minor radiation leak equal to the same radiation you get from space anyway or a gear set failure causing wild spinning and instability?

Nuclear batteries use peliters or something to harness the heat from nuclear decay, meaning exactly zero moving parts for most.


----------



## digibucc (Nov 29, 2012)

i feel smarter just for having read over your posts


----------



## ALMOSTunseen (Nov 29, 2012)

Frick said:


> Hey would you say no to this?
> 
> https://upload.wikimedia.org/wikipedia/en/e/e8/Ford_Nucleon.jpg


That car looks like its a nuclear payload system.....


----------



## FordGT90Concept (Nov 29, 2012)

Steevo said:


> More parts, more chances for failure. Unlike even an aircraft where if an engine fails they still land safely in an hour, in space, and months away from home would you rather suffer a minor radiation leak equal to the same radiation you get from space anyway or a gear set failure causing wild spinning and instability?
> 
> Nuclear batteries use peliters or something to harness the heat from nuclear decay, meaning exactly zero moving parts for most.


Turbines and electric servos have very, very few parts compared to piston systems.

They don't use nuclear reactors on manned craft because the radiation shielding alone would make it probitive to put in space.

"Nuclear batteries" have very low electric output (less than 200 watts) and it diminishes over time.




ALMOSTunseen said:


> That car looks like its a nuclear payload system.....


It's a Ford Nucleon.  It was a concept car--never got a nuclear reactor.


----------



## Depth (Nov 29, 2012)

ALMOSTunseen said:


> Forget about brain cells, where is my nuclear powered car?



Forget about cars, where are my nuclear powered brain cells?


----------



## Steevo (Nov 29, 2012)

Fuel storage under pressure, regulation, ignition, lubrication, oxygenator storage under pressure.

Radioactive batteries last years and the shielding/security in space is minimal compared to what a permanent terra installation requires as in space whos going to try and steal it?

http://en.wikipedia.org/wiki/Atomic_battery


Its not about the energy conversion efficiency so much as life-cycle and dependency.


----------



## Inceptor (Dec 3, 2012)

This is an interesting idea, but yeah, some engineering issues to deal with.
I recall reading a paper about small self contained reactors for usage 'off-earth', building a small reactor is definitely doable right now, it's decades old military tech.


----------



## de.das.dude (Dec 3, 2012)

Frick said:


> Forget about space, where is my nuclear powered car??



similar reason to why you dont put a diesel engine on a bike.



arent stirling engines like useless?


----------



## 3870x2 (Dec 3, 2012)

Frick said:


> Hey would you say no to this?



Striking similarities


----------



## Steevo (Dec 3, 2012)

I saw my cooler in the basement in a box the other day and cringed about how ugly it really looks in person.


----------



## RejZoR (Dec 19, 2012)

nt300 said:


> They do require lots of torque.
> This s old news. Remember the Orion Project 45+ years ago? If they continued with that project man would be in deep space right now. This was suppose to travel between 19km to 31km per second
> 
> 
> ...



Amazing. I've done some calculations and if it was going with its peak speed of 31 km/s we could reach Mars in roughly 30 days. Reaching Eris from Earth when it's roughly 10 billion km away would take around 10 years. And we are talking outer edge of our solar system here. Voyager 1 probe needed over 30 years for the ame journey!


----------



## a_ump (Dec 19, 2012)

Steevo said:


> Fuel storage under pressure, regulation, ignition, lubrication, oxygenator storage under pressure.
> 
> Radioactive batteries last years and the shielding/security in space is minimal compared to what a permanent terra installation requires as in space *whos going to try and steal it?*
> 
> ...



DOT DOT DOT *DOTT DOTT!!*


----------

