[HN Gopher] The Globus INK: a mechanical navigation computer for...
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       The Globus INK: a mechanical navigation computer for Soviet
       spaceflight
        
       Author : picture
       Score  : 72 points
       Date   : 2023-01-21 17:37 UTC (5 hours ago)
        
 (HTM) web link (www.righto.com)
 (TXT) w3m dump (www.righto.com)
        
       | borissk wrote:
       | No doubt similar systems were installed on the soviet ICBMs,
       | probably still in use today.
        
         | krisoft wrote:
         | > No doubt similar systems were installed on the soviet ICBMs
         | 
         | I very much doubt it. This is a display unit. Has zero purpose
         | on an uncrewed system.
         | 
         | Furthermore ballistic missiles remain suborbital. This device
         | is usefull to track your position on orbit.
         | 
         | Ballistic missiles don't reenter using retro rockets, so
         | showing the reentry point to the no-existing crew in case they
         | activate the non-existing retro rockets has limited usefullness
         | either.
         | 
         | In short ICBM's don't have this or similar systems for the same
         | reasons they don't have cuckoo clocks. They are not usefull
         | there.
        
       | cleansingfire wrote:
       | Wow! An analog dead reckoning computer with a beautiful display.
       | I'm especially intrigued by the cam based CVT (constantly
       | variable transmission.) I'm glad to know this exists. Thank you
       | for sharing the details.
        
       | kens wrote:
       | Author here if you have questions about the Globus or other space
       | hardware.
        
         | janoc wrote:
         | No questions but thanks to all of you guys. That's one heck
         | fascinating stuff you are working on there and big kudos for
         | researching and documenting the tech history!
         | 
         | I remember seeing this Globus device in all Russian spaceflight
         | photos since I was a kid and we learned about Gagarin and
         | others (I am from ex-communist country) - and nobody has ever
         | published much information about how this thing works, until
         | now. Yet it was a staple of Soviet spaceflight until early
         | 2000s and similar devices flew also on all Soviet space
         | stations (Salyuts, Mir).
        
           | krisoft wrote:
           | > nobody has ever published much information about how this
           | thing works
           | 
           | I'm afraid you are mistaken on that. The instrument has a
           | very extensive wikipedia page since years: https://en.m.wikip
           | edia.org/wiki/Voskhod_Spacecraft_%22Globus...
        
         | usgroup wrote:
         | This is a naive question, but how does one even begin to
         | conceive of a device like this? What does a "mechanical
         | computer" development life cycle look like?
        
           | contingencies wrote:
           | Not so different from software I would hazard a guess.
           | Document requirements (accuracy over intended usage period,
           | human interface, weight, size) and identify potential
           | subsystems and interfaces. Obtain industrial base with both
           | practical and theoretical expertise in mechanical
           | engineering. Brainstorm possible solutions and compare to
           | requirements. Prototype and iterate. Test. Train.
        
           | kens wrote:
           | I think it's basically a process of figuring out the
           | equations you want, then how to "mechanize" them with gears,
           | cams, and differentials. Then it is mechanical engineering to
           | fit all the gears in a box. (The equations are generally much
           | simpler than you'd implement in software, and you're not
           | dealing with algorithms.)
           | 
           | Another thing is that the Globus went through multiple
           | revisions so the original didn't have as much functionality.
           | So it's kind of like any project where you make the minimum
           | viable product and then incrementally add features.
        
           | nosianu wrote:
           | Just like with electronics, it all started with individual
           | components. It only looks so incredibly complex when all
           | those individual units are composed into a big whole.
           | 
           | Underneath it there is order similar to the layering of
           | software though.
           | 
           | Here are a few mechanical computing components explained, the
           | context here was real-time in- and output to control ship
           | guns against ground, sea or air targets, taking into account
           | own speed, angles, angular speeds, distances and their
           | changes, and other factors, like wind, if they could be
           | measured.
           | 
           | https://youtu.be/s1i-dnAH9Y4 -- "Basic Mechanisms In Fire
           | Control Computers - US Navy 1953"
           | 
           | So, the engineers coming up with the top level design
           | probably did not think in "gears" but in higher level
           | computing and transmission units.
        
             | iancmceachern wrote:
             | Exactly, we think in terms of interfaces. The apollo moon
             | mission technical history is a good example. At a high
             | level there is a big diagram with things like transmissions
             | and modules drawn as single blocks. We define how those
             | blocks need to interact with eachother. Then teams of
             | engineers work on each block, designing and making each
             | block to do what it was defined to do on that big flow
             | chart. Each part is tested to its interfaces (which can be
             | mechanical, electrical, hydraulic, control, etc) and if
             | each part does what it's supposed to the whole thing
             | should.
        
       | Koshkin wrote:
       | > _The name Globus (Globus) seems to be a nickname, and I suspect
       | it 's more commonly used in English than Russian._
       | 
       | Actually, "globus" is just the Russian word for the familiar
       | model of the globe (like those found in classrooms), which is
       | what this thing is. No mystery there :)
        
       | 082349872349872 wrote:
       | > _Although the Globus is mostly mechanical, it has an
       | electronics board with four relays and a transistor_
       | 
       | a transistor (!!)
        
         | kens wrote:
         | The funny thing about this germanium transistor is that it
         | looks like a TO-3 power transistor package, the large flanged
         | metal. But the Russian packaging is different: the flange is
         | separate from the transistor and clamps down the round
         | transistor package. I'm not sure that makes sense, but here's
         | an eBay photo: https://www.ebay.com/itm/203509582918
        
           | schiffern wrote:
           | Archived for posterity: https://archive.ph/J9mEb
        
           | Koshkin wrote:
           | > _I 'm not sure that makes sense_
           | 
           | Maybe this is done in order to decouple the orientation of
           | the leads from that of the holes, so one does not force the
           | other? (Just a guess.)
        
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       (page generated 2023-01-21 23:00 UTC)