proto at panix.com
Mon Nov 23 18:07:56 GMT 2020
> On Nov 23, 2020, at 10:29 AM, Markus Baur via Lois-Bujold <lois-bujold at lists.herald.co.uk> wrote:
> let us take the arecibo design as plubeprint and look where we can reduce mass
> the dish itself can be made from very lightweight aluminized foil (it does not have to deal with wind and rain) - this also means that the anchor cables for the dish can be made a lot thinner.
> we also might not make the cables (both for the dish and the gondola) from aluminium or steel - modern synthetics like Spectra offer a much better weight / strength ratio
> the receiver gondola suspended over the dish also does not have to deal with weather ..
> so i would not be surprised if it could be built with only 1/10 of the mass of the original
> total weight of the arecibo observatory seems to be around 1500 tons .. so a lunar arecibo would be around 150 tons
> and that is not completely out of bounds, if SpaceX gets the lunar version of the Starship to work (estimated paylaod to lunar surface aruond 40 tons .. 4 flights .. getting the resto of the necessary infrastructure (quarters for construction and maintenance crew, constructrion machinery, etc. ) up might take even more paylaod than the telescope itself
More feasible would put it in low Earth orbit, where there is radiation protection from the Earth’s magnetic field,
and it can scan more of the sky. This give better logistics including retrieval of personnel and significantly less
lag time in communication.
OBbj: Remember the time lag when Miles had his conversation with Dr. Auditor Vorthys?
Alternatively perhaps it could be located at L4 or L5, if we are OK with remote operation and it
could be assembled in low Earth orbit.
It is wrong, always, everywhere, and for everyone, to believe anything upon insufficient evidence.”
—W. K. Clifford (1845–1879), “The Ethics” My take is belief should be proportional to the evidence.
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