Various...

[... Stranded astronauts trying to get to the moon ...]

> However it might be possible if they landed on the planet with vacc suits,
> given a generous ref :-).

Very generous indeed!

> Using the high altitude glider + balloons to gain
> altitude they could then have constructed some simple rockets fueled with,
> say alcohol, and use the remaining atmosphere coupled with the oxygen
> supplies from some of their vacc suits - this would be a one man trip only.

Getting high in the atmosphere does not mean that it will be any easier to get
into orbit.  There's still a slight problem of achieving 8 km/s.

I'd be amazed if a simple alcohol rocket could get 1 km/s exhuast velocity,
and even so it would take 200 tons of fuel to get a single person into orbit.
Multiply by 20 to get to the moon.

[...]

> This one guy then has the time it takes him to reach the moons surface from
> maximum vacc suit communication range to tell the TL15 ship to pick him
> up - otherwise he's dead. (A kinder alternative would be to allow him
> to achieve orbit round the moon - but that might overtax his vacc suit's
> computer, prehaps a decaying orbit? :-)

I'd like to see someone plot a decaying orbit around the moon!  No atmosphere
to slow the guy down means little chance of orbital decay.

Overtaxing the vacc-suit computer would be less of a problem (*especially*
at TL15 - hand supercomputers are TL11 stuff), compared to the problem of
needing yet more fuel...

- -*-*-*-*-*-

> 1> How "thick" is our galaxy? (in parsecs or light years) If I'm mapping it
>    into 3D, I want to have a general idea of how much vertical space I have
>    to work with.

It varies a fair bit, but 1000 parsecs is a reasonable guide.  As far as
Traveller goes, there is effectively no vertical limit.

> 2> Lots of SF works speak of nebulas. Where are these things located and how
>    big are they? I've not seen any descriptions of these in Traveller and it
>    seemed like a neat thing to include.

Nebulae are located all over the galaxy.  Dark nebula range in size from the
lower limit of observation up to galaxy-spanning lanes.  Bright nebulae
are usually only a few light years across, but can reach hundreds of light-
years if illuminated (or ionised) by very bright stars.  They wouldn't have
much game-mechanical effect - they pretty much 'just look cool'.  Density of
gas/dust in a nebula is still so low that interplanetary space looks like
osmium in comparison.  It's only because the thickness is so large, that you
can see anything.

- --
Tim Little