On Sat, 24 Feb 2018 07:50:49 -0800, "shadow at shadowgard.com (via tml
list)" <xxxxxx@simplelists.com> wrote:

>On 23 Feb 2018 at 20:29, Jeff Zeitlin wrote:
>
>> ... as posed in my previous question to the list, what do you use to
>> get a ship from dirtside to space, without having to completely snap
>> the suspenders of disbelief?

>Well, you could leave the ship in orbit and ride some sort of shuttle
>up and down. That's doable with WWII era tech if you want to work at
>it. Maybe lower.

This is actually for an alternate setting that is essentially Drake's RCN
universe with the serial numbers filed off, possibly with elements from
_Vatta's War_ and/or the Liaden Universe® incorporated; shuttles/lighters
aren't really an option. Unlike Drake, I'm allowing 'grav plates' for in a
ship - or a space station - specifically to enable (but not require)
certain cultural options and differentiate it from Drake. Effective TL is
pretty much 8 or 9, except for having the attractive gravity manipulation -
grav plates and tractor beams - but no pressors/repulsors, and no gravity
screening/negating (except by putting an attractor _above_ the area you
want to lessen gravity in. And no, you don't get to cheat by faking
grav-based perpetual motion).

>Given fusion reactors (hot fusion, not cold fusion) you can create
>quite a rocket. If "raw" fusion rocket is a bit much for you (ie the
>exhaust is basicly plasma from the reactor run thru an MHD "nozzle")
>you can just use the reactor to heat liquid hydrogen to very high
>temperatures and run it through a more normal nozzle.

>The higher the temp of the exhaust, the better the Isp. That is, the
>higher the exhaust velocity the less fuel you need for the same
>acceleration.

So, Drake more-or-less got it right with his plasma thrusters (using any
room-temperature liquid as 'working fluid') for getting through the
atmosphere, and powering the ship through a 'fusion bottle'.

(That, of course, leads to the question of whether his "high drive", pretty
much the same thing but done with a matter/antimatter reaction, is
plausible for an exoatmospheric reaction drive. And ignores the question of
where the antimatter comes from.)

(Your other ideas, while interesting, are for different settings entirely -
but thanks for the ideas; good ones are hard to find...)

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