Re: starship-design: Timothy's beamed power paper

[jimaclem@juno.com]

On Mon, 21 Jul 1997 18:04:05 +0200 (MET DST) Zenon Kulpa
<zkulpa@zmit1.ippt.gov.pl> writes:

>> Hope this is better.  The sail pulls a column that passes through 
>the
>> sail, with the payload on top, away from the Earth side of the sail.
>> 
>Sorry, did not work this time either.
>
>Concerning the idea itself, I have doubts:
>- the central compression column must quite thick, hence heavy:
>  the problem is not so much with compression strength
>  as with bending of long (relative to width) objects
>  compressed lengthwise (the effect is called "buckling"
>  if I am not mistaken).

Actually, the central column would be a truss, relatively light-weight
but strong.  You are correct about buckling, though, the seminal work was
by Euler (see any engineering mechanics text, look up Euler's Columns).

>- the construction will be rather unstable (like Wright brothers
>  early planes, with their tail-first design): the central column
>  wil tend to veer to the sides.
>

Good point about the stability.

>The parachute design seems much better; the payload can be
>shielded from the beam by a small sail supported by correspondingly
>small truss structure.
>
>-- Zenon
>