Groups > sci.electronics.design > #519107

Re: various OTs

From	"Tim Williams" <tiwill@seventransistorlabs.com>
Newsgroups	sci.electronics.design
Subject	Re: various OTs
Date	2018-10-12 19:10 -0500
Organization	A noiseless patient Spider
Message-ID	<pprd4s$8s2$1@dont-email.me> (permalink)
References	<r2u1sddojvr815ukjlm0qhsr5bpa2fbe6s@4ax.com>

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I want to say a lot of terrestrial gyros are air-bearing supported, of 
course that literally doesn't "fly" so well in space.  I suppose it could be 
a pressurized module.  Maybe that's not a good way to go overall, say 
because of precession rate.

The recent spate of reaction wheel failures apparently is an ESD phenomenon. 
Radiation causes photoemission on the bearing surfaces, accumulating charge, 
which eventually discharges through the grease, pitting the bearing balls 
and races, causing rising power consumption until the ratings are met and 
the thing grinds to a halt.

The solution: use insulating (ceramic) bearings.

Tim

-- 
Seven Transistor Labs, LLC
Electrical Engineering Consultation and Design
Website: https://www.seventransistorlabs.com/

"John Larkin" <jjlarkin@highland_snip_technology.com> wrote in message 
news:r2u1sddojvr815ukjlm0qhsr5bpa2fbe6s@4ax.com...
>
> https://wattsupwiththat.com/2018/10/12/another-space-telescope-shuts-down-one-week-after-hubble/
>
> Gyros, reaction wheels, seem to be a chronic problem in satellites. I
> have a friend who designs cubesats, and he says that the gyros are the
> most expensive and unreliable parts. They should be redundant, or
> redesigned, or something.
>
> ===========
>
> Another friend, a Fellow of a giant areospace conglomerate, tells me
> that they have a new CEO. The old one was big on outsourcing, and they
> did stuff like using contract programmers in India, and things went to
> hell. They will be hiring 8000 engineers in the next few years, so
> they can start learning how to do stuff again.
>
> ===========
>
> This is a cool part:
>
> http://www.ti.com/product/lmg1020
>
>
>
>
> -- 
>
> John Larkin         Highland Technology, Inc
> picosecond timing   precision measurement
>
> jlarkin att highlandtechnology dott com
> http://www.highlandtechnology.com
>

Thread

various OTs John Larkin <jjlarkin@highland_snip_technology.com> - 2018-10-12 12:50 -0700
  Re: various OTs George Herold <gherold@teachspin.com> - 2018-10-12 13:04 -0700
    Re: various OTs John Larkin <jjlarkin@highland_snip_technology.com> - 2018-10-12 13:48 -0700
      Re: various OTs George Herold <gherold@teachspin.com> - 2018-10-12 17:46 -0700
  Re: various OTs dplatt@coop.radagast.org (Dave Platt) - 2018-10-12 14:53 -0700
    Re: various OTs John Larkin <jjlarkin@highland_snip_technology.com> - 2018-10-12 15:30 -0700
      Re: various OTs Martin Brown <'''newspam'''@nezumi.demon.co.uk> - 2018-10-13 10:13 +0100
        Re: various OTs John Larkin <jjlarkin@highlandtechnology.com> - 2018-10-13 09:33 -0700
          Re: various OTs Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2018-10-13 14:15 -0400
          Re: various OTs Martin Brown <'''newspam'''@nezumi.demon.co.uk> - 2018-10-15 10:09 +0100
            Re: various OTs John Larkin <jjlarkin@highlandtechnology.com> - 2018-10-15 06:50 -0700
    Re: various OTs Clive Arthur <cliveta@nowaytoday.co.uk> - 2018-10-13 10:37 +0100
      Re: various OTs DecadentLinuxUserNumeroUno@decadence.org - 2018-10-13 10:01 +0000
        Re: various OTs John Larkin <jjlarkin@highland_snip_technology.com> - 2018-10-13 11:08 -0700
      Re: various OTs John Larkin <jjlarkin@highlandtechnology.com> - 2018-10-13 09:55 -0700
      Re: various OTs MikeP <mjp993@googlemail.com> - 2018-10-16 03:22 +0000
    Re: various OTs Robert Baer <robertbaer@localnet.com> - 2018-10-13 22:39 -0700
      Re: various OTs Sjouke Burry <burrynulnulfour@ppllaanneett.nnll> - 2018-10-14 21:43 +0200
        Re: various OTs Robert Baer <robertbaer@localnet.com> - 2018-10-15 19:46 -0700
  Re: various OTs DecadentLinuxUserNumeroUno@decadence.org - 2018-10-12 23:55 +0000
    Re: various OTs Lasse Langwadt Christensen <langwadt@fonz.dk> - 2018-10-12 16:58 -0700
    Re: various OTs bill.sloman@ieee.org - 2018-10-12 17:52 -0700
    Re: various OTs speff <spehro@gmail.com> - 2018-10-18 06:53 -0700
      Re: various OTs John Larkin <jjlarkin@highlandtechnology.com> - 2018-10-18 06:59 -0700
        Re: various OTs tabbypurr@gmail.com - 2018-10-18 14:10 -0700
          Re: various OTs "Tim Williams" <tiwill@seventransistorlabs.com> - 2018-10-18 17:49 -0500
        Re: various OTs Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2018-10-18 21:04 -0400
          Re: various OTs Steve Wilson <no@spam.com> - 2018-10-19 01:34 +0000
            Re: various OTs <698839253X6D445TD@nospam.org> - 2018-10-19 07:11 +0000
  Re: various OTs "Tim Williams" <tiwill@seventransistorlabs.com> - 2018-10-12 19:10 -0500
    Re: various OTs Lasse Langwadt Christensen <langwadt@fonz.dk> - 2018-10-13 06:22 -0700
      Re: various OTs Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2018-10-13 14:16 -0400
        Re: various OTs John Larkin <jjlarkin@highlandtechnology.com> - 2018-10-13 17:19 -0700
    Re: various OTs whit3rd <whit3rd@gmail.com> - 2018-10-13 12:24 -0700
      Re: various OTs Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2018-10-13 17:30 -0400
        Re: various OTs Jasen Betts <jasen@xnet.co.nz> - 2018-10-14 20:13 +0000
          Re: various OTs John Larkin <jjlarkin@highland_snip_technology.com> - 2018-10-14 13:59 -0700
            Re: various OTs Steve Wilson <no@spam.com> - 2018-10-14 23:58 +0000
              Re: various OTs Steve Wilson <no@spam.com> - 2018-10-15 01:05 +0000
                Re: various OTs Jasen Betts <jasen@xnet.co.nz> - 2018-10-15 05:57 +0000
                Re: various OTs DecadentLinuxUserNumeroUno@decadence.org - 2018-10-15 11:09 +0000
              Re: various OTs <698839253X6D445TD@nospam.org> - 2018-10-15 07:23 +0000
      Re: various OTs "Tim Williams" <tiwill@seventransistorlabs.com> - 2018-10-13 21:39 -0500
  Re: various OTs bitrex <user@example.net> - 2018-10-13 00:08 -0400
  Re: various OTs <698839253X6D445TD@nospam.org> - 2018-10-13 06:59 +0000
    Re: various OTs John Larkin <jjlarkin@highland_snip_technology.com> - 2018-10-13 12:08 -0700
  Re: various OTs <698839253X6D445TD@nospam.org> - 2018-10-13 07:27 +0000
    Re: various OTs speff <spehro@gmail.com> - 2018-10-18 06:55 -0700
  Re: various OTs Winfield Hill <hill@rowland.harvard.edu> - 2018-10-13 07:32 -0700
    Re: various OTs John Larkin <jjlarkin@highland_snip_technology.com> - 2018-10-13 12:17 -0700
  Re: various OTs Joseph Gwinn <joegwinn@comcast.net> - 2018-10-15 08:37 -0400
    Re: various OTs Martin Brown <'''newspam'''@nezumi.demon.co.uk> - 2018-10-15 13:58 +0100
      Re: various OTs Tom Gardner <spamjunk@blueyonder.co.uk> - 2018-10-15 14:34 +0100
      Re: various OTs Clifford Heath <no.spam@please.net> - 2018-10-16 10:26 +1100
    Re: various OTs Clive Arthur <cliveta@nowaytoday.co.uk> - 2018-10-16 10:46 +0100
      Re: various OTs tabbypurr@gmail.com - 2018-10-16 08:46 -0700
        Re: various OTs Clive Arthur <cliveta@nowaytoday.co.uk> - 2018-10-16 19:53 +0100
          Re: various OTs tabbypurr@gmail.com - 2018-10-17 05:56 -0700

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