4 ms·

Detailed articles on the avionics of NASA’s space shuttle

79 points by stevenhuang 8y ago

deleted 8y ago
[deleted]
qume 8y ago
Wow this covers a lot of my job, and is really concise and well written. This might be the best link ever posted to HN for me. Thank you.
- exikyut 8y ago
  What kind of job do you do? My vague guess is NASA historian or tour guide.
  - petermcd 8y ago
    These articles would be of interest to anyone developing flight avionics systems for spacecraft, airplanes, or, I can imagine, drones.
    - qume 8y ago
      Yea flight avionics, sort of. Aerial camera systems and the UI to control them.
      - exikyut 8y ago
        Wow, that sounds really cool. I really like the UI design that goes into avionics - the fact that every possible scenario has to be thought out and handled, and that the end result has no flashy eyecandy or extraneous functionality; it's all function, it's all required (or it's not there); everything on the screen at any given time is significant, and (hopefully) care is taken that the amount of data (ie, significance) showing at any one moment is not information overload. A very hard balance to get right, I'm sure. The rigor and discipline imposed over the process of software architecture and implementation in aviation (moreso than medical devices, it would seem) is both inspiring and instructive, and I definitely look up to it. I must admit I'm genuinely interested to learn more about how the role of UI design plays into avionics construction - I've leaned toward UX for quite a while (I think I started headscratching about the subject around 13-14, although I didn't know that was what it was called at the time) and I think it's probably something I'd do pretty well at when I'm finally looking for a job. Web UX is... frustrating and demotivating, though. I don't want to kill myself doing that.
exikyut 8y ago
This is awesome. But it has no pictures! And the font is so tiny :( my eyes can read it, but my brain's getting scared by the walls of text. What I'd love to see is photos of the various modules, and then further photos of all the insides. -- Probably the thing I want the most - as crazy as this probably sounds - is a character ROM dump. I like fonts from old things :/ I recently learned that the bit of avionics with the weird keyboard in it that's typically found in "large" aircraft is called a Control Display Unit, or CDU. (Here's a random 747 cockpit with two shown facing upwards: http://flic.kr/p/aFRHt4 http://flic.kr/p/aFRHt4). I did an image search for CDU font, and promptly had one of those times I immediately hit the jackpot: http://sigmatechnica.com/lynx-helecopter-cdu-semi-teardown/ http://sigmatechnica.com/lynx-helecopter-cdu-semi-teardown/ has a 2048x1536 photo of someone who randomly got a CDU from a Lynx helicopter off eBay to poke at, and took a bunch of photos of everything they could make it do, including the font-self test! That's the kind of thing I wish I had, but for random industrial equipment - and, sure, the space shuttle. (Know where I can find ROMs for old avionics? lol) For the VT220 font-rendering geeks, the CRT in the mentioned CDU (no model info :( ) happens to be mounted vertically.
- dexen 8y ago
  From the second link, >Interestingly the indicators are incandescent bulbs… >an odd choice as they have used LEDs as indicators on the PCBs as we will see later. Lightbulbs have well-understood failure mode (open circuit) and detection of such failures; it's exceedingly rare for a lightbulb to fail half-way. Contrast that with LEDs which can fail while remaining as either open or closed circuit. This (costly & lengthy airworthiness certification aside) is why even modern airliners use lightbulbs for avionics indicators - often in redundant pairs. One of very few maintenance items commercial pilots are allowed, and indeed trained, to perform routinely is replacing the indicator lighbulbs. In-depth coverage by Mentour Pilot: https://www.youtube.com/watch?v=RifyTCwwNy0 https://www.youtube.com/watch?v=RifyTCwwNy0
  - exikyut 8y ago
    TIL! For a few seconds I started thinking about packaging LEDs with onboard LDRs so any failure that results in not-100%-light-output produces an open circuit... but I can see the result having too many moving parts to comfortably pass certification. If such a thing is even possible to make. Your mention that LEDs can fail closed rules out a current-consumption monitoring system... And then a "light up all the indicator lights" button (which IIRC does exist?) connected to a camera and machine vision system would _work_, but it'd probably be a ton more expensive (to build _properly_) than just sticking with incandescent bulbs.
forapurpose 8y ago
There's much more than avionics if you navigate up the path: https://spaceflight.nasa.gov/shuttle/reference/ https://spaceflight.nasa.gov/shuttle/reference/

79 points by stevenhuang 8y ago

deleted 8y ago

[deleted]

qume 8y ago

Wow this covers a lot of my job, and is really concise and well written. This might be the best link ever posted to HN for me. Thank you.

exikyut 8y ago
What kind of job do you do? My vague guess is NASA historian or tour guide.
- petermcd 8y ago
  These articles would be of interest to anyone developing flight avionics systems for spacecraft, airplanes, or, I can imagine, drones.
  - qume 8y ago
    Yea flight avionics, sort of. Aerial camera systems and the UI to control them.
    - exikyut 8y ago
      Wow, that sounds really cool. I really like the UI design that goes into avionics - the fact that every possible scenario has to be thought out and handled, and that the end result has no flashy eyecandy or extraneous functionality; it's all function, it's all required (or it's not there); everything on the screen at any given time is significant, and (hopefully) care is taken that the amount of data (ie, significance) showing at any one moment is not information overload. A very hard balance to get right, I'm sure. The rigor and discipline imposed over the process of software architecture and implementation in aviation (moreso than medical devices, it would seem) is both inspiring and instructive, and I definitely look up to it. I must admit I'm genuinely interested to learn more about how the role of UI design plays into avionics construction - I've leaned toward UX for quite a while (I think I started headscratching about the subject around 13-14, although I didn't know that was what it was called at the time) and I think it's probably something I'd do pretty well at when I'm finally looking for a job. Web UX is... frustrating and demotivating, though. I don't want to kill myself doing that.

exikyut 8y ago

This is awesome. But it has no pictures! And the font is so tiny :( my eyes can read it, but my brain's getting scared by the walls of text. What I'd love to see is photos of the various modules, and then further photos of all the insides. -- Probably the thing I want the most - as crazy as this probably sounds - is a character ROM dump. I like fonts from old things :/ I recently learned that the bit of avionics with the weird keyboard in it that's typically found in "large" aircraft is called a Control Display Unit, or CDU. (Here's a random 747 cockpit with two shown facing upwards: http://flic.kr/p/aFRHt4 http://flic.kr/p/aFRHt4). I did an image search for CDU font, and promptly had one of those times I immediately hit the jackpot: http://sigmatechnica.com/lynx-helecopter-cdu-semi-teardown/ http://sigmatechnica.com/lynx-helecopter-cdu-semi-teardown/ has a 2048x1536 photo of someone who randomly got a CDU from a Lynx helicopter off eBay to poke at, and took a bunch of photos of everything they could make it do, including the font-self test! That's the kind of thing I wish I had, but for random industrial equipment - and, sure, the space shuttle. (Know where I can find ROMs for old avionics? lol) For the VT220 font-rendering geeks, the CRT in the mentioned CDU (no model info :( ) happens to be mounted vertically.

dexen 8y ago
From the second link, >Interestingly the indicators are incandescent bulbs… >an odd choice as they have used LEDs as indicators on the PCBs as we will see later. Lightbulbs have well-understood failure mode (open circuit) and detection of such failures; it's exceedingly rare for a lightbulb to fail half-way. Contrast that with LEDs which can fail while remaining as either open or closed circuit. This (costly & lengthy airworthiness certification aside) is why even modern airliners use lightbulbs for avionics indicators - often in redundant pairs. One of very few maintenance items commercial pilots are allowed, and indeed trained, to perform routinely is replacing the indicator lighbulbs. In-depth coverage by Mentour Pilot: https://www.youtube.com/watch?v=RifyTCwwNy0 https://www.youtube.com/watch?v=RifyTCwwNy0
- exikyut 8y ago
  TIL! For a few seconds I started thinking about packaging LEDs with onboard LDRs so any failure that results in not-100%-light-output produces an open circuit... but I can see the result having too many moving parts to comfortably pass certification. If such a thing is even possible to make. Your mention that LEDs can fail closed rules out a current-consumption monitoring system... And then a "light up all the indicator lights" button (which IIRC does exist?) connected to a camera and machine vision system would _work_, but it'd probably be a ton more expensive (to build _properly_) than just sticking with incandescent bulbs.

forapurpose 8y ago

There's much more than avionics if you navigate up the path: https://spaceflight.nasa.gov/shuttle/reference/ https://spaceflight.nasa.gov/shuttle/reference/