Re: RE: starship-design: Interstellar Probes

[KellySt@aol.com]

In a message dated 8/14/98 6:06:37 PM, f96bni@student.tdb.uu.se wrote:

>On Tue, 11 Aug 1998, L. Parker wrote:
>
>> Gene,
>> 
>> Robert Forward proposed an interstellar probe based on a perforated sail
>> design combined with gravity assist and beamed microwave power. The payload
>> was to be 4 grams of intelligent microcircuitry embedded within the actual
>> structure of the craft - something that is not so far fetched any more - we
>> actually know how to do this!
>> Forward's calculations showed that we could accelerate starwisp (his name
>> for it) to 20 percent of the speed of light within only a few days. This
>> would deliver the probe to Alpha Centauri within about twenty years.
>> 
>> You must note however, that this is a "flyby" at twenty percent of the
speed
>> of light with a very limited payload and extremely limited data return. It
>> may not be very useful, especially in light of what we can potentially see
>> from Earth orbit with advanced optics.
>> 
>
>Excuse my Ignorance but wouldn't it be possible to Use the target Star's
>Gravity to "swing" the probe around and into a return orbit to Earth (or
>at least close enough to our solar system to be recovered in some way.)
>
>Just curious...


Not at those speeds.  When you get up to fractions of light speed, gravity
manuvers need close apraoches to a black hole.

Kelly