Nuclear Laser Fusion Engines oO

[Belesarius]

http://nosint.blogspot.ca/2015/07/boeing-patents-laser-powered-fusion.html

 

I've seen this come across a couple of pages that I follow, and my FB feed as well.

Looks interesting. 

[Collimatrix]

I saw this as well.  Similar ideas were floating around in the 1970s for "fusion microexplosion" improved Orion-type propulsion.

 

I'm not sure why in the video above the presenter thinks this thing is for aircraft.  The patent doesn't mention aircraft at all, and it's not very practical for aircraft.

 

The presenter is dead wrong when he says this would be clean.  That U238 fast-fission blanket would be producing fission products, which are of course intensely radioactive and bad for you.

[Vanagandr]

Reminds me of nuclear pulse propulsion. Very neat, but I'd think parts would wear out quickly and the fuel would be less convenient than liquid fuel.

[Collimatrix]

It basically is nuclear pulse propulsion.  Far-sighted futurists in the 1970s proposed a lot of improved variants of NPP using pure-fusion "microexplosions" for improved specific impulse and reduced shock absorber mass.

 

The only minor tiny little detail problem is that nobody knows how to ignite fusion reactions without using fission reactions.

 

This one is an interesting hybrid where the neutron shielding doubles as fast-fission reaction mass.  On paper this reduces your specific impulse a bit, but you needed the shielding to be there anyhow, so it's more a nominal loss than a real one.  This is also what makes this design not in the least bit "clean."

[LostCosmonaut]

It sounds not entirely unlike the technology that would have been used in Project Daedalus, or Longshot.