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Re: starship-design: Re: Perihelion Maneuver
In a message dated 11/18/97 2:33:10 AM, kuo@bit.csc.lsu.edu wrote:
>L. Parker wrote:
>>On Monday, November 17, 1997 11:15 AM, Isaac Kuo [SMTP:kuo@bit.csc.lsu.edu]
>>wrote:
>
>>> He never bothered with the engineering difficulties of making
>>> and stabalizing such a huge fresnel lens, though.
>
>>Not to switch sides or anything, but I don't believe the fresnel lens will
>>even work for several different reasons. His use of the fresnel lens was
>>for a larger, manned proposal. The Starwisp received ALL of its
>>acceleration while still within range of the original...uhh, maser.
>
>No, it still needs a fresnel lens. Without it, diffraction limits
>are too severe. The beam needs to fall on a spot 1km wide at a
>range of 30,000,000,000km. With a wavelength of 1mm, that requires
>an aperture around 30,000km wide. Don't tell me you're going to
>make a microwave laser that big.
As I mentioned a phased array maser cluseer of 2 AU recently (for fuel sail),
and we have done extensive conversations of it a year ago, I'ld think we'ld
already covered that to death? Hell they're even talking optical telescope
clusters on that scale.
Kelly