Is Nuclear Power the Future of Space Propulsion?

[Winzer]

Is there any research being done for: using nuclear power for space propulsion?

 

[cam875]

heres some info

http://en.wikipedia.org/wiki/Nuclear_propulsion
http://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion )

 

[Astronuc]

Is there any research being done for: using nuclear power for space propulsion?

In short yes, but the funding is very limited, and NASA and others have other priorities.

 

[russ_watters]

The simplest form of nuclear propulsion to develop would be a nuclear powered ion drive. Ion drives work and just need electricity, so I'm not sure there would be that steep of a curve to develop one...there'd just have to be a need.

 

[Winzer]

The simplest form of nuclear propulsion to develop would be a nuclear powered ion drive. Ion drives work and just need electricity, so I'm not sure there would be that steep of a curve to develop one...there'd just have to be a need.

Those are interesting, but the thrust is small compared to a chemical engine, or maybe for our theoretical nuclear engine.

It just seems to me nuclear power in space fits. It is definitely sustainable. The reaction itself on a spacecraft would be dangerous though.

 

[theCandyman]

I think the upcoming ANS meeting in June will have a talk about NETS (nuclear and emerging technologies for space). You could probably find out which papers will be discussed and get a copy if you have access to academic journels at your university.

 

[Astronuc]

One can find links to space nuclear power here, including some papers in pdf.

http://anstd.ans.org/ [Mentors' note - this is a correction to a broken link]

Project Prometheus was the latest NASA/DOE program in an attempt to achieve something along the lines of nuclear propulsion in space. But coming as it did after the loss of Columbia, and when O'Keefe was given the directive to reduce cost, it was one of the programs to be indefinitely deferred. Nuclear power (and propulsion) is at the bottom of the list at NASA.

 

[M98Ranger]

One of my fellow undergraduates is currently working with Idaho National Laboratory (INL) on a project having to do with developing nuclear power for space

 

[Bob S]

The simplest form of nuclear propulsion to develop would be a nuclear powered ion drive. Ion drives work and just need electricity, so I'm not sure there would be that steep of a curve to develop one...there'd just have to be a need.

Ion drives also need a bottle (or many bottles) of xenon gas or other high mass ion for consumption as the propellant. To understand the advantage of ion mass,

Energy E = (1/2) m v².
Momentum p = m v
Therefore p = sqrt(2 m E)

So you get more thrust from a high mass ion.

See http://en.wikipedia.org/wiki/Ion_engines#Propellants

 

[Lancelot59]

Over a long term mission that seems like it would be a bit of a large load. Carrying enough gas for a several month journey.

Although you wouldn't be constantly burning the engines the whole way to your destination.

How about an engine design like this?

http://en.wikipedia.org/wiki/Farnsworth-Hirsch_Fusor

 

[Astronuc]

With respect to energy requirements of ion propulsion, it is actually preferable to use ions of least mass in order to maximize ion speed/velocity.

let qV = 1/2 mv², where q is the charge, V is the accelerating potential, m is the ion mass, and v is the exhaust velocity

then v = sqrt(2qV/m).


Xe is preferable from the standpoint of it's low ionization potential compared to other gases, but the trade off is low Isp. And actually, Cs is perhaps even better from the standpiont of ionziation potential.

Hydrogen would be ideal for Isp, but it has high ionization potential (13.6 eV) and low density in gas and liquid form, and liquid is disadvantageous from the standpoint of cryogenic systems.

Diborane B₂H₆ would be an interesting propellant, but it's very explosive in air.

 

[Lancelot59]

Although seeing as the air in space is so thin that wouldn't be a problem. The tanks would just have to be atmospherically isolated from the rest of the ship. Kept in an unpressurized section.