Re: Towards routine, reusable space launch.

From	willner@cfa.harvard.edu (Steve Willner)
Newsgroups	rec.arts.sf.science, sci.astro, sci.physics, sci.space.policy
Subject	Re: Towards routine, reusable space launch.
Date	2018-06-15 18:59 +0000
Organization	Harvard-Smithsonian Center for Astrophysics
Message-ID	<pg129r$5ll$1@dont-email.me> (permalink)
References	(8 earlier) <7sguhdp3btbbbs83nm5la7lrl7vgg1j6a8@4ax.com> <pfon5t$9p8$1@dont-email.me> <rqe0idpd5fvuh1k50f8f1e88ji18sqj6ff@4ax.com> <pfpn9a$ss8$1@dont-email.me> <cs91idhasmjd9qbdhmk4qajkgr1u3jp7fg@4ax.com>

Cross-posted to 4 groups.

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> >The [JWST] telescope is folded, not only the solar arrays.

In particular the 6.5-m primary mirror is folded as well as many
other pieces.  It's frightening to watch the deployment videos.

In article <cs91idhasmjd9qbdhmk4qajkgr1u3jp7fg@4ax.com>,
 Fred J. McCall <fjmccall@gmail.com> writes:
> And THAT is because you cannot make a single mirror that large to
> adequate precision,

At least three observatories with seven telescopes in active use will
be surprised to learn that.  Not to mention additional ones planned.

Every JWST presentation I've seen that mentioned the subject said
that using a deployable (folding) mirror is because the Ariane 5
shroud is too small to fit a 6.5-m mirror.  I wouldn't be surprised
if there are "black" programs with the same difficulty.

That said, this particular use case doesn't necessarily justify a
rockoon approach, which will be difficult at best for large boosters.

-- 
Help keep our newsgroup healthy; please don't feed the trolls.
Steve Willner            Phone 617-495-7123     swillner@cfa.harvard.edu
Cambridge, MA 02138 USA

Thread

Re: Towards routine, reusable space launch. Doc O'Leary  <droleary@2017usenet1.subsume.com> - 2018-06-11 22:35 +0000
  Re: Towards routine, reusable space launch. Fred J. McCall <fjmccall@gmail.com> - 2018-06-11 20:58 -0700
    Re: Towards routine, reusable space launch. Doc O'Leary  <droleary@2017usenet1.subsume.com> - 2018-06-12 15:00 +0000
      Re: Towards routine, reusable space launch. Fred J. McCall <fjmccall@gmail.com> - 2018-06-12 14:36 -0700
        Re: Towards routine, reusable space launch. Alain Fournier <alain245@videotron.ca> - 2018-06-12 20:08 -0400
          Re: Towards routine, reusable space launch. Fred J. McCall <fjmccall@gmail.com> - 2018-06-12 22:12 -0700
            Re: Towards routine, reusable space launch. willner@cfa.harvard.edu (Steve Willner) - 2018-06-15 18:59 +0000
              Re: Towards routine, reusable space launch. Fred J. McCall <fjmccall@gmail.com> - 2018-06-15 12:13 -0700
                Re: Towards routine, reusable space launch. willner@cfa.harvard.edu (Steve Willner) - 2018-06-18 20:36 +0000
                Re: Towards routine, reusable space launch. Fred J. McCall <fjmccall@gmail.com> - 2018-06-18 19:57 -0700
                Re: Towards routine, reusable space launch. willner@cfa.harvard.edu (Steve Willner) - 2018-06-25 21:17 +0000
                Re: Towards routine, reusable space launch. Fred J. McCall <fjmccall@gmail.com> - 2018-06-25 15:52 -0700

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