Nuclear Fusion Rockets v.s Fission

[Arian]

you are basically saying its too complicated

 

[Astronuc]

It certainly is complicated.

I know this is one of Zubrin's ideas (http://www.npl.washington.edu/AV/altvw56.html) , but I'd have to review the details of his calculations, particularly the efficiency of the fission process.

It is very easy to consider I_sp = v_ex/g, but is the vex based on the actual physics. If only the water is considered, then the calculation of I_sp is incorrect. One must consider the presence of U and fission products in the stream. I would be interested in Zubrin's core design.

The other aspect is the materials degradation (corrosion/erosion) - which I suspect may not have been addressed.

 

[Arian]

actually i was thinking about that while I read your response yesterday, but i was unfuitful coming up with a fission chamber that would move up the rocket at the rate that metal errored away.

 

[Astronuc]

actually i was thinking about that while I read your response yesterday, but i was unfuitful coming up with a fission chamber that would move up the rocket at the rate that metal errored away.

Well there is such a concept using Am-242m which undergoes spontaneous fission and has a reasonable fission cross-section. But the spontaneous fissioning is also a problem for handling and assembly. The spontaneous fission cannot be switched off and on - it is continuously on.

Erosion is a problem not only for fission systems, but any high temperature system, particularly where flow is involved.