Feasibility study of a mission to Sedna – Nuclear propulsion and solar sailing

This direct fusion drive is a really interesting concept. Maybe something like this could be used for interstellar travel in a century (or five), it is very encouraging that there is active research on it. ~5kg of thrust is not a lot, but over time...

This sounds significantly more feasible than nuclear pulse propulsion ("project orion" style) which I used to think was the only feasible approach to get to another star.

One thing that was unclear from the paper to me: How does the fusion drive "pick" D/He3 fusion over D/D? Can this be "forced" by just cranking the plasma temperature way up? Or do you still just have to deal with a bunch of neutrons from undesired D/D fusion?

> This sounds significantly more feasible than nuclear pulse propulsion ("project orion" style) which I used to think was the only feasible approach to get to another star.

I still carry a torch for project Orion, it's impossible to not love.

* Feasible 50 years ago, not 50 years from now.

* No ultra lightweight fancy space age materials, steel and lots of it.

* Seriously, lots of it, let's launch a battleship to to Mars,

* or Jupiter,

* or Alpha Centauri.

* Gives everyone something way better to do with all those nuclear bombs they have laying around.

I once spoke to Freeman Dyson at a book signing and asked him if Orion would work. He said he thought it would. And I asked him if it should be launched. He said probably not (IIRC due to the amount of radiation that would be put into the atmosphere).

It is almost the epitome of steampunk romance. Launch an entire mid-20th century city and economy into space! And it might even work!

But, yeah, you probably don't want to be launching these routinely. People generally badly underestimate the number of nuclear explosions that have been set off on Earth and overestimate the badness of nuclear explosions. Putting one or two of these into orbit might be justifiable. It's certainly not a bad emergency plan to have in your pocket in case of emergencies. But you still certainly wouldn't want an entire industry routinely lighting these things off.

Still... the romance of it all...!