Re: starship-design: unmanned missions, AI, etc.

[Lindberg <lindberg@olywa.net>]

Lee, 
Regarding detection of starships from afar.  If we assume that
starships, both alien and human, are driven by fusion rockets or some
other engine which produces plasma exhaust (likely, in my opinion), the
plume of relativistic plasma should be visible from quite a distance
(i'm too lazy to do the math).  Its heat signature should be even
brighter.  I assume any civilization that is sending out starships would
have a large constellation of "superHubbles" of which many would be
monitoring nearby starsystems.  Exhaust trails would give them away. 
Incedentaly, tho' i don't favor arming robot probes, a manned crew could
save themselves from hostile craft (including other humans) by using
their engine as a thermonuclear flamethrower.

>The worst case scenario would be one of stumbling across another scouting
probe
> before our probe detected it (likely) then they would at least be able to
> get a rough bearing. Of course, we could always make it a practice to flyby
> multiple star systems using the gravity well of each system to alter to a
> heading for the next destination.

	Good idea about the gravity assist. Also, this 'worst case' scenario is
only valid if the probe actually returned.  A one-way robot mission
could radio a directional signal back home.  Unless the hypothetical
alien craft were in the proper position (in the way of earth or one of
the other radio lobes), it would not have any idea of where earth is
(unless it were near enough to see the dish getting turned, in which
case our probe could probably detect it).  Besides, spacefaring aliens
are far from the top of the danger list.  To paraphrase Douglas Adams,
space is really big.
Nels Lindberg