Reply To: Richard Branson – Virgin Pledge

[Duke Leto]

1) I’m not sure that the Helium stream would provide thrust with anything close to the efficiency that it provides deceleration electricity, since ion drives provde minimal constant acceleration over long distances.

2) I also gather from your description that the alpha stream would be going through the fan system, that would mean that the reactor must be located in the center. I think this would mean that:

a) It would be much more difficult to maintain the needed pressure of the Hydrogen-Boron fuel.
b) You would be pouring unspent fuel into the atmosphere or whereever at an alarming rate, and thus wasting Boron.
c) You’d be shooting fully energized ionizing alpha particles into the environment, which I believe is nastier then Gamma.

I’ll defer to your judgement on these points, since I don’t have a Nuclear background.

Keep in mind I’m looking to have engines that fit into existing vehicles without too much fuss, not next generation machines.

Man this looks terrible without list tags.