[time-nuts] Re: The Collapse of Puerto Rico’s Iconic Telescope [April 5th, 2021 New Yorker]

[Lux, Jim]

On 3/30/21 5:42 PM, Magnus Danielson wrote:
>> What *is* a challenge (and hasn't really been solved) is how to do
>> cryogenic feeds in mass production.  DSN looked at building an array
>> of 100 receivers, and nobody would sign up to delivering 100
>> cryocoolers that would have sufficient MTBF.   But transmitting -
>> that's easy.
> In that case the request was not aligned with what industry could
> deliver. Sounds like there is room for an advancement program to push
> the capability of the industry, so requests like that can be made. Then
> that faces challenges to have large enough volume to have multiple
> vendor being able to bid on it, and make sure multiple vendors do get bids.

They did all that. Got some prototypes.  Cryocoolers of that size are 
sort of a specialized thing, apparently.  It's probably in some 
technical reports from about 15 years ago.  JPL did a bunch of 
experiments - we temporarily had a couple of 6m and a 12m dish installed 
on lab, and I think there was one down on Caltech campus.

Here's a presentation from Sandy Weinreb
https://descanso.jpl.nasa.gov/seminars/abstracts/viewgraphs/DSN_array_dev_program.pdf

and one from Joe Statman

https://descanso.jpl.nasa.gov/seminars/abstracts/viewgraphs/DSAN_040729.pdf

If you read them, note the dates for the missions - JWST, Lunar Hab, etc.