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  • So far, Webb has apparently worked as hoped

    From RichA@21:1/5 to All on Fri Jan 7 06:45:07 2022
    Put out its heat/light shield and has extended the secondary mirror.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From StarDust@21:1/5 to RichA on Fri Jan 7 11:07:41 2022
    On Friday, January 7, 2022 at 6:45:09 AM UTC-8, RichA wrote:
    Put out its heat/light shield and has extended the secondary mirror.

    Hubble was the same way, until they started using it.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Chris L Peterson@21:1/5 to All on Fri Jan 7 16:37:22 2022
    On Fri, 7 Jan 2022 11:07:41 -0800 (PST), StarDust <csoka01@gmail.com>
    wrote:

    On Friday, January 7, 2022 at 6:45:09 AM UTC-8, RichA wrote:
    Put out its heat/light shield and has extended the secondary mirror.

    Hubble was the same way, until they started using it.

    The HST optics were not tested on the ground. These were.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From StarDust@21:1/5 to Chris L Peterson on Fri Jan 7 21:57:16 2022
    On Friday, January 7, 2022 at 3:37:25 PM UTC-8, Chris L Peterson wrote:
    On Fri, 7 Jan 2022 11:07:41 -0800 (PST),
    wrote:
    On Friday, January 7, 2022 at 6:45:09 AM UTC-8, RichA wrote:
    Put out its heat/light shield and has extended the secondary mirror.

    Hubble was the same way, until they started using it.
    The HST optics were not tested on the ground. These were.

    I guess, they learned something!
    Far as I know, the instrument used for testing the optics of Hubble were calibrated wrong, so it gave a false result!
    That's why Hubble had astigmatism, which was corrected later!

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Martin Brown@21:1/5 to Chris L Peterson on Sat Jan 8 09:30:51 2022
    On 07/01/2022 23:37, Chris L Peterson wrote:
    On Fri, 7 Jan 2022 11:07:41 -0800 (PST), StarDust <csoka01@gmail.com>
    wrote:

    On Friday, January 7, 2022 at 6:45:09 AM UTC-8, RichA wrote:
    Put out its heat/light shield and has extended the secondary mirror.

    Hubble was the same way, until they started using it.

    The HST optics were not tested on the ground. These were.

    How did they do that?

    I would have thought that gravity would distort the thing way too much
    to be able to do full scale imaging tests of the whole telescope.
    Obviously you can test each of the individual segments.

    The HST optics were tested on the ground with an esoteric precision
    reference test jig. The problem was that there was a systematic error in
    how that component had been assembled. It was an unfortunate case of not
    fully understanding the difference between precision and accuracy.

    The HST primary was very precisely figured and polished to exactly the
    wrong shape - thanks to that fundamental error in the reference jig.

    The spare HST mirror was made correctly by an independent contractor
    Eastman Kodak.

    --
    Regards,
    Martin Brown

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From StarDust@21:1/5 to Martin Brown on Sat Jan 8 02:07:16 2022
    On Saturday, January 8, 2022 at 1:30:55 AM UTC-8, Martin Brown wrote:
    On 07/01/2022 23:37, Chris L Peterson wrote:
    On Fri, 7 Jan 2022 11:07:41 -0800 (PST),
    wrote:

    On Friday, January 7, 2022 at 6:45:09 AM UTC-8, RichA wrote:
    Put out its heat/light shield and has extended the secondary mirror.

    Hubble was the same way, until they started using it.

    The HST optics were not tested on the ground. These were.
    How did they do that?

    I would have thought that gravity would distort the thing way too much
    to be able to do full scale imaging tests of the whole telescope.
    Obviously you can test each of the individual segments.

    The HST optics were tested on the ground with an esoteric precision
    reference test jig. The problem was that there was a systematic error in
    how that component had been assembled. It was an unfortunate case of not fully understanding the difference between precision and accuracy.

    The HST primary was very precisely figured and polished to exactly the
    wrong shape - thanks to that fundamental error in the reference jig.

    The spare HST mirror was made correctly by an independent contractor
    Eastman Kodak.

    --
    Regards,
    Martin Brown

    I worked in Aerospace 12 years,
    but sometimes I had this feeling, it's a pyramid of dummies running the show!

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Chris L Peterson@21:1/5 to '''newspam'''@nonad.co.uk on Sat Jan 8 07:18:47 2022
    On Sat, 8 Jan 2022 09:30:51 +0000, Martin Brown
    <'''newspam'''@nonad.co.uk> wrote:

    On 07/01/2022 23:37, Chris L Peterson wrote:
    On Fri, 7 Jan 2022 11:07:41 -0800 (PST), StarDust <csoka01@gmail.com>
    wrote:

    On Friday, January 7, 2022 at 6:45:09 AM UTC-8, RichA wrote:
    Put out its heat/light shield and has extended the secondary mirror.

    Hubble was the same way, until they started using it.

    The HST optics were not tested on the ground. These were.

    How did they do that?

    I would have thought that gravity would distort the thing way too much
    to be able to do full scale imaging tests of the whole telescope.
    Obviously you can test each of the individual segments.

    The HST optics were tested on the ground with an esoteric precision
    reference test jig. The problem was that there was a systematic error in
    how that component had been assembled. It was an unfortunate case of not >fully understanding the difference between precision and accuracy.

    The HST primary was very precisely figured and polished to exactly the
    wrong shape - thanks to that fundamental error in the reference jig.

    The spare HST mirror was made correctly by an independent contractor
    Eastman Kodak.

    I'm not sure. Read about the details on some site a year or so ago.
    The optics were bench tested as a complete assembly. That's what was
    not done with the HST, where each element was tested separately.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Jos Bergervoet@21:1/5 to StarDust on Sat Jan 8 17:51:30 2022
    On 22/01/08 6:57 AM, StarDust wrote:
    On Friday, January 7, 2022 at 3:37:25 PM UTC-8, Chris L Peterson wrote:
    On Fri, 7 Jan 2022 11:07:41 -0800 (PST),
    wrote:
    On Friday, January 7, 2022 at 6:45:09 AM UTC-8, RichA wrote:
    Put out its heat/light shield and has extended the secondary mirror.

    Hubble was the same way, until they started using it.
    The HST optics were not tested on the ground. These were.

    I guess, they learned something!
    Far as I know, the instrument used for testing the optics of Hubble were calibrated wrong, so it gave a false result!
    That's why Hubble had astigmatism,

    Really? I thought it only had spherical abberation. For astigmatism
    something woud have to be off-axis, or in some other way not
    rotationally symmetric.. I don't think that was the problem.

    --
    Jos

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Jos Bergervoet@21:1/5 to Martin Brown on Sat Jan 8 17:55:45 2022
    On 22/01/08 10:30 AM, Martin Brown wrote:
    On 07/01/2022 23:37, Chris L Peterson wrote:
    On Fri, 7 Jan 2022 11:07:41 -0800 (PST), StarDust <csoka01@gmail.com>
    wrote:

    On Friday, January 7, 2022 at 6:45:09 AM UTC-8, RichA wrote:
    Put out its heat/light shield and has extended the secondary mirror.

    Hubble was the same way, until they started using it.

    The HST optics were not tested on the ground. These were.

    How did they do that?

    I would have thought that gravity would distort the thing way too much
    to be able to do full scale imaging tests of the whole telescope.
    Obviously you can test each of the individual segments.

    The HST optics were tested on the ground with an esoteric precision
    reference test jig. The problem was that there was a systematic error in
    how that component had been assembled. It was an unfortunate case of not fully understanding the difference between precision and accuracy.

    The HST primary was very precisely figured and polished to exactly the
    wrong shape - thanks to that fundamental error in the reference jig.

    The spare HST mirror was made correctly by an independent contractor
    Eastman Kodak.

    Then why didn't they see an error in the spare?! That would have
    undoubtedly led to a denial by E. Kodak and then the whole analysis
    would have resulted in using the spare instead of the wrong one, I
    would imagine..

    --
    Jos

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Quadibloc@21:1/5 to Martin Brown on Sat Jan 8 17:10:32 2022
    On Saturday, January 8, 2022 at 2:30:55 AM UTC-7, Martin Brown wrote:

    The spare HST mirror was made correctly by an independent contractor
    Eastman Kodak.

    The reason the HST mirror was tested only one way, which turned out to
    yield incorrect results, was because it was being made in a highly classified facility also used to make spy satellites.

    It's a pity there wasn't the budget to put up a second Hubble using the
    Eastman mirror, as it would have performed better, and I'm sure
    astronomers would have appreciated the extra scope time. It's not as
    if two Hubbles would have cost twice as much, so it would have been
    a bargain.

    John Savard

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From palsing@21:1/5 to Quadibloc on Sat Jan 8 21:13:57 2022
    On Saturday, January 8, 2022 at 5:10:33 PM UTC-8, Quadibloc wrote:

    It's a pity there wasn't the budget to put up a second Hubble using the Eastman mirror, as it would have performed better, and I'm sure
    astronomers would have appreciated the extra scope time. It's not as
    if two Hubbles would have cost twice as much, so it would have been
    a bargain.

    Is it too late? :>)

    Whatever happened to that mirror?

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Chris L Peterson@21:1/5 to All on Sat Jan 8 21:41:10 2022
    On Sat, 8 Jan 2022 17:10:32 -0800 (PST), Quadibloc <jsavard@ecn.ab.ca>
    wrote:

    On Saturday, January 8, 2022 at 2:30:55 AM UTC-7, Martin Brown wrote:

    The spare HST mirror was made correctly by an independent contractor
    Eastman Kodak.

    The reason the HST mirror was tested only one way, which turned out to
    yield incorrect results, was because it was being made in a highly classified >facility also used to make spy satellites.

    It's a pity there wasn't the budget to put up a second Hubble using the >Eastman mirror, as it would have performed better, and I'm sure
    astronomers would have appreciated the extra scope time. It's not as
    if two Hubbles would have cost twice as much, so it would have been
    a bargain.

    All the sadder considering that the repair job cost as much as another
    HST would have. And all the repairs could have paid for several.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From RichA@21:1/5 to Chris L Peterson on Sat Jan 8 22:45:38 2022
    On Saturday, 8 January 2022 at 23:41:18 UTC-5, Chris L Peterson wrote:
    On Sat, 8 Jan 2022 17:10:32 -0800 (PST), Quadibloc <jsa...@ecn.ab.ca>
    wrote:
    On Saturday, January 8, 2022 at 2:30:55 AM UTC-7, Martin Brown wrote:

    The spare HST mirror was made correctly by an independent contractor
    Eastman Kodak.

    The reason the HST mirror was tested only one way, which turned out to >yield incorrect results, was because it was being made in a highly classified
    facility also used to make spy satellites.

    It's a pity there wasn't the budget to put up a second Hubble using the >Eastman mirror, as it would have performed better, and I'm sure
    astronomers would have appreciated the extra scope time. It's not as
    if two Hubbles would have cost twice as much, so it would have been
    a bargain.
    All the sadder considering that the repair job cost as much as another
    HST would have. And all the repairs could have paid for several.

    Still about 1/100th the cost of the ISS p.o.s. and 1000x more productives.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Quadibloc@21:1/5 to palsing on Sun Jan 9 10:43:37 2022
    On Saturday, January 8, 2022 at 10:13:59 PM UTC-7, palsing wrote:

    Is it too late? :>)

    Well, they don't have the Space Shuttle any longer.

    Whatever happened to that mirror?

    It's in the Smithsonian. If it wasn't for the pandemic, you could go and see it.

    John Savard

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Quadibloc@21:1/5 to Quadibloc on Sun Jan 9 10:47:32 2022
    On Sunday, January 9, 2022 at 11:43:39 AM UTC-7, Quadibloc wrote:
    On Saturday, January 8, 2022 at 10:13:59 PM UTC-7, palsing wrote:

    Is it too late? :>)

    Well, they don't have the Space Shuttle any longer.

    Whatever happened to that mirror?

    It's in the Smithsonian. If it wasn't for the pandemic, you could go and see it.

    Here you are:

    https://airandspace.si.edu/collection-objects/mirror-primary-backup-hubble-space-telescope/nasm_A20010288000

    John Savard

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Martin Brown@21:1/5 to Jos Bergervoet on Mon Jan 10 09:55:26 2022
    On 08/01/2022 16:55, Jos Bergervoet wrote:
    On 22/01/08 10:30 AM, Martin Brown wrote:
    On 07/01/2022 23:37, Chris L Peterson wrote:
    On Fri, 7 Jan 2022 11:07:41 -0800 (PST), StarDust <csoka01@gmail.com>
    wrote:

    On Friday, January 7, 2022 at 6:45:09 AM UTC-8, RichA wrote:
    Put out its heat/light shield and has extended the secondary mirror.

    Hubble was the same way, until they started using it.

    The HST optics were not tested on the ground. These were.

    How did they do that?

    I would have thought that gravity would distort the thing way too much
    to be able to do full scale imaging tests of the whole telescope.
    Obviously you can test each of the individual segments.

    The HST optics were tested on the ground with an esoteric precision
    reference test jig. The problem was that there was a systematic error
    in how that component had been assembled. It was an unfortunate case
    of not fully understanding the difference between precision and accuracy.

    The HST primary was very precisely figured and polished to exactly the
    wrong shape - thanks to that fundamental error in the reference jig.

    The spare HST mirror was made correctly by an independent contractor
    Eastman Kodak.

    Then why didn't they see an error in the spare?! That would have

    The spare was made entirely separately no testing methods shared.
    Kodak's simpler test was less precise but correct.

    undoubtedly led to a denial by E. Kodak and then the whole analysis
    would have resulted in using the spare instead of the wrong one, I
    would imagine..

    The method for finding out what was wrong with it once the fault was
    discovered when it had first light was devised at Jodrell bank for
    figuring the panels on their big radio dish to a perfect parabola.

    The same holographic phase method will also be used to fine tune this
    set of mirror segments on Webb into the final imaging array.

    --
    Regards,
    Martin Brown

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)