[gurps] [VEHICLE] Building a hard-SF interstellar ship?

[Pauli Hakala]

Onno Meyer wrote:
> Have you considered laser-boosted lightsails? VXi14 is not clear about
> the maximum range of such a system - if it is uses normal combat range
> rules, the laser is completely useless, so let us assume the range is 
> something decent. 
> 
> You could mount a disposable lightsail for the launch and (less) fuel
> for braking.  
> 

I guess that this method works best for light mission payload probes
and the like.. Manned missions require heavy radiation shielding to
protect the crew against cosmic radiation, especially if realistic
rules are used for radiation shielding PF.

> Pauli wrote:
>> Another way to go would be to use up several ice chunks along
>> the way - the Oort Cloud is full of suitable targets, and
>> has a radius of several light-years.
> 
> Unless you happen to find one going the right way at a fairly high
> speed, you have to brake and spend fuel to catch the fuel. Perhaps
> you could use ONE stepping stone to refuel for braking if your 
> overall travel speed is similar to that of comets. Millenia to the
> next system ...
> 

Yeah, Oort Cloud objects are usually fairly slow. Using several
stepping stones would allow for mining of resources on the way,
as well as setting up comm relays, but it would increase the
travel time.

Using a single Oort Cloud object as reaction mass would be
reasonably fast though, and very cost-effective. Such an
object gives reaction mass, armor and radiation shielding
- The expedition just needs to provide for reaction engines
like Fission Drives or Mass Drivers.


-Pauli
-- 
"Accompanied only by the full moon, howling of
the nightwolf, and the path under my bare feet,
the elvenpath.."
-Nightwish, Angels Fall First: Elvenpath