On 23Feb2018 0752, Bruce  Johnson wrote:

> I don’t have FF&S handy, But I do remember that T4 introduced the
> hack that these kinds of vehicles were powered by some sort of ‘cold
> fusion’ style reactor.

TNE/FF&S air/rafts used MHD turbines, and thus were usually not
vacuum-rated. If they were, they'd need both oxygen and hydrogen fuel
and thus had reduced operational duration. That's for a TL12 model. At
TL14 a fusion plant has a small enough minimum volume (and thus mass) to
be worth using. At TL15 batteries are *almost* as good as a TL8 MHD
plant that can air-breathe. So, unless you really need the low profile
of batteries and are TL15, it's a fusion plant (TL14+) or most likely an
MHD turbine.

TL12 CG for an air/raft used 0.3MW power. The HEPlaR thruster used about
the same (using reactionless thrusters gets more thrust per MW but
they're massier, which is probably a wash in an air/raft). If neither of
these technologies suits, ducted fans could be used, but they'd make for
a slower (and atmospheric only, obviously) craft.

--
Rupert Boleyn <xxxxxx@gmail.com>
Chief Assistant to the Assistant Chief