7 ms·

Space Shuttle teleprinter reverse engineering

106 points by DAddYE 2y ago

generj 2y ago
I am fascinated they used 60 pounds and a large amount of space for this teleprinter. At 30K per pound of payload that is $1.8 million per flight. Really shows how important reliable printed updates were considered. And all the flaws of the printer that were managed around - turning it off to save power and prevent it overheating with specific tones.
- eddieroger 2y ago
  I was pretty stuck by that, too, and it made me wonder if maybe I don't understand or underestimate the value of paper transmission. I suppose if radio communication is good but flaky, or for persistence of instruction, like procedures, then it would be good for them to be able to print. But at such a cost!
  - willcipriano 2y ago
    [flagged]
    - actionfromafar 2y ago
      This is true, but in hindsight only a partial success. A good chunk of the communists weren't. :-/
      - a_gnostic 2y ago
        Communism is the very definition of failure. Return, refit, and redeploy to purge the stain of this failure with the peroxide of victory!
  - krisoft 2y ago
    I guess with modern googles one would just pack an "ipad" equivalent tablet. If one worries about accidents and freak space particles disabling it give them 3. If one still worries one can develop a "space rated" tablet. But probably at those radiation levels one should also start worrying about the crew's health. But of course that is projecting our current capabilities back in time. I looked it up and the "Osborne 1" portable computer[1] was just released 9 days before the shuttle's first flight. It weighed 24.5 lb (11.1 kg) and could display 52 x 24 characters on a small CRT. So yeah, that would not be nice to read manuals with :D 1: https://en.wikipedia.org/wiki/Osborne_1 https://en.wikipedia.org/wiki/Osborne_1
    - generj 2y ago
      Right it clearly was the best choice for the time the shuttle was developed but just shows how removed from the 1960s and 70s we are today. My earlier point about payload weight was probably the wrong focus. Mission success and maximizing what the crew can accomplish in orbit are greatly facilitated by one way text from ground control, and doubtlessly paid for the 60 pounds Astronauts were already used to Telex weather reports as pilots so existing UX. And the crew specialists all had PhDs and thus were experts at reading typed paper. So no training on yet another shuttle subsystem. The teletype could be effectively shared between crew - just tear off the paper. A portable computer could only be used by one or two people, AND would need to be radiation hardened and aerospace qualified.
    - amelius 2y ago
      iPads are more hazardous than you think: https://appleinsider.com/articles/23/07/14/fatal-helicopter-crash-likely-caused-by-dropped-ipad https://appleinsider.com/articles/23/07/14/fatal-helicopter-...
      - kayodelycaon 2y ago
        Not really an iPad-specific issue. A clipboard or checklist could have done the same thing.
  - dylan604 2y ago
    Maybe they remember the situation with Apollo 13 where they had no way to right down the procedures other than by hand and using space pages from the existing printed documents. You then had the issue where the guys were so fatigued and CO2 levels getting to a point of making vision blurry. I could see where that might have factored into the decision of wanting to avoid all of that with the ability of printing new/modified procedures.
    - dylan604 2y ago
      too late to edit, but right != write <hangsHeadInShame>
  - shagie 2y ago
    Remember that this was also before easily portable electronics. Today you'd get a PDF and store it on your iPad. Secure it for landing and you're good. All the documents you want. In the 80s consider the "Mission Control has new landing procedures that you need to follow. Here is a 42 item check list that you'll need to do before initiating task 357 from the mission specification." How do you get that 42 item check list? Do you write it down? What that transcribed properly? Was that a P or a B that the person heard over the radio? (Yes, I know Bravo Papa). Here's a secret objective for the mission ( https://ntrs.nasa.gov/api/citations/20110023479/downloads/20110023479.pdf https://ntrs.nasa.gov/api/citations/20110023479/downloads/20... ) to preform while in orbit that has now been approved and was not part of the initial mission profile. The instructions will be printed out and are for the captain and pilots eyes only. There are a number of reasons that one may need a secure printer to handle new documents while on the Space Shuttle. With 70s and 80s tech, the approach taken is reasonable.
- KineticLensman 2y ago
  > I am fascinated they used 60 pounds and a large amount of space for this teleprinter. IIRC the Zion space habitat in Neuromancer had a state-of-the-art line printer which at one point spews continuous-fold paper into the weightless environment. They had however got rid of the slide-rules that were essential in early-era Arthur C Clarke spaceships
  - throwanem 2y ago
    That was Haniwa, not Zion. The printer was spewing paper because someone had put a laser through its faceplate while Corto was taking the ship. Also, Haniwa is described explicitly and implicitly as an exoatmospheric luxury yacht, and thus likely wasn't designed for high acceleration. Also, I'm pretty sure it was a thermal printer, not a line printer as here. Also, Neuromancer is period-piece literary sf. So I'm not necessarily sure how relevant it is here.
    - KineticLensman 2y ago
      In terms of relevance, I was amused that real and contemporary fictional spacecraft both had paper printers
      - lsllc 2y ago
        The question is, would the craft now need help from reaction wheels to offset the inertia from the moving print head / paper feed? Or would there need to be a special version of the printer firmware that kept track of its movement so it could always impart equal but opposite inertia?
        throwanem 2y ago
        Since a thermal printer only needs as much pressure on the platen roller as required to keep the paper registered, the roller itself could be hollow and thus carry negligible inertia. The print head could be net neutral by operating boustrophedonically, which many printers already do - both of my inkjets, for example! - and that might actually count for more, considering the possible need for some thermal mass to dissipate waste heat from the printing elements. (I don't think modern thermal printers need that, but I suppose in the 80s they might have.) Worst case, the firmware might need to ensure the number of head passes is even, I think most simply by counting print passes and if needed performing a final "return" pass with a cold head - again a common behavior, and one also displayed by both my inkjets since that avoids the need for a parking station on either side of the paper path. The line printer with its heavy drum would probably be more of a concern for the Shuttle, although I doubt a significant one. Reaction wheels function by change in angular momentum, and a line printer drum spins at a fixed rate in operation; as long as spinup and spindown take about the same time, which is easy enough to achieve, the net effect on attitude should be negligible, especially considering the entire printer constitutes only about 1/3000 of the orbiter's dry mass. You might not want to run the thing during an OMS burn, but even if you did I doubt it'd matter; assuming constant thrust from spinup through spindown, your course would be displaced proportionally to the length of the print job, but given the minimal relative inertia and that line printers typically output in the tens of hundreds of lines per second I think it'd need quite a long job to make a noticeable difference, and you'd almost certainly run out of paper long before. (Don't take any of this too seriously; I'm the wrong kind of engineer to give authoritative answers here, but the question is fun to think about anyway.)
- beerandt 2y ago
  The thing that immediately jumped into my head is coded military use. Especially since they mention the printer being based on a military design. It's still rather obscure, if not still secret, just to what extent we were actually using the shuttles in their intended military capacity. But when designed, the military use was expected to be much much higher than what panned out. This printer would be high on the list of the weight budget, to the point that I wonder if it wasn't critical protocol to some still secret military use, similar to the teletype nuke codes / orders on a sub. Running over the audio system also makes me curious if it was strictly unencrypted comms, or if it could plug in to a decrypted steam. Were they clear broadcasting coded messages, or encrypted-broadcast clear messages (or both or neither). IIRC, NASA used to have at least some 'private' comms with astronauts that were in the clear, but they basically just didn't rebroadcast to the public or publicize those currently used frequencies, and just sort of trusted those in the know not to listen in.
  - samstave 2y ago
    [flagged]
    - dylan604 2y ago
      what a useless post and your last sentence is just made up from thin air. if you believe any of that, you probably think the earth is flat, the moon landing was shot on a film stage in hollywood. a simple web search will show the actual reasons for the shuttle disasters.
    - DaSHacka 2y ago
      > I think Challenger was sabotage Mind explaining your reasoning? As someone not very familiar with the details, I'm curious
      - samstave 2y ago
        As much as Dylan wants to denegrate my post: I have always believed the Shuttle was sabotaged. I watched it live when it happened when I was a kid and followed all aspect from the lead up (we voted for Kristy in my school IIRC) -- but there has always been a lot of weird strangeness about the shuttle and the demise of its occupants. Ant to Dylan - relax - I can speculatively hold dystopian-sci-fi what-ifs without your other slanders. Its a fun and more entertaining topic than most movies. I said I do not know what happened, I said I believe the challenger was sabotaged, with my disclaimer that I do not know. The theories about the astronauts being alive are silly but well crafted fiction. Dylan got triggered a bit to hard by my comments. -- The reason I feel the challenger was sabotaged is also backed up by CIA documents: https://i.imgur.com/ylDBcDH.png https://i.imgur.com/ylDBcDH.png https://www.cia.gov/readingroom/docs/CIA-RDP88B00443R001904460005-6.pdf https://www.cia.gov/readingroom/docs/CIA-RDP88B00443R0019044... But Ill let Dylan do his own research. >Plus "do his own research" is awfully adjacent to the Q-unacy. That was the joke, jeasus. as he is the one accusing me of being flat-earth moon denier. Read the linked PDF from the CIA FFS. Its a fun theory and that has multiple articles linked from the 80s. So a "simple web search" of shit that went down in the decades before the internet isnt as simple, nor reliable as one would hope. However - I am sure Dylan Called Google and knows all about it.
- tyingq 2y ago
  Here's my guess. Government bureaucracy is probably very high for anything space related. So "based on the military's AN/UGC-74" could have helped get it through approvals. It would have ticked a lot of boxes for ruggedized parts, use in harsh environments, and so on.
  - beerandt 2y ago
    I don't doubt that for a second- but I'm more curious about the requirement for some kind of printout in the first place. Especially since it ultimately ended up weighing what it did. Military/ Ruggedized is a smart choice for a printer that needs to go through that environment, no matter the why. I'm more interested in what it tells us about the underlying purpose (or what it might rule out, like the part about wired directly into unencrypted comms).
    - tyingq 2y ago
      Oh, I didn't consider that, since I was a young person then. Sticking notes, directives, etc, everywhere was just really common. So if they get a note about extra daily checks on equipment X, they print/affix the note to the equipment. Or other similar needs. There would probably be limited screens, so anything you wanted to be known to everyone, becomes a note.
    - jcrawfordor 2y ago
      I don't think the requirement for printed output requires any appeal to military applications. They would have been exchanging navigation information with mission control over the radio. That's all mission critical and needs to be read back. Anything they got via voice they would have to write down. Getting it by text in the first place would increase reliability and reduce cockpit workload. You also get in-flight information like weather that you'll want to write down for later reference. Teleprinter writes it for you so you can review it at your leisure. Airliners and ships at sea have both historically used teleprinters for the same reasons, although the modern navigation computers have mostly eliminated the need.
- amelius 2y ago
  > At 30K per pound of payload that is $1.8 million per flight. Yeah, but they could save by using white-label ink cartridges.
marcodiego 2y ago
X (twitter) is useless for threads unless you're logged in. How can I read this thread?
- ghosty141 2y ago
  Yeah somebody should mirror it. In general I dont understand why people post things like this on X. Its a horrible platform.
  - bookofjoe 2y ago
    For some; for technically dumb people like me, it's the only platform that's easy to use.
  - bagels 2y ago
    What are some better alternatives?
    - omoikane 2y ago
      Current best answer seem to be Mastodon and Bluesky. If we are going by the number of users, Facebook has more users than Twitter and Threads has about the same order of magnitude, but we still see a lot more Twitter submissions to HN compared to Facebook and Threads[1]. If users prefer the microblog format, Mastodon and Bluesky appear to be the most compelling alternatives, both have been steadily gaining users[2]. [1] Submissions from various sites: https://news.ycombinator.com/from?site=twitter.com https://news.ycombinator.com/from?site=twitter.com https://news.ycombinator.com/from?site=threads.net https://news.ycombinator.com/from?site=threads.net https://news.ycombinator.com/from?site=facebook.com https://news.ycombinator.com/from?site=facebook.com https://news.ycombinator.com/from?site=bsky.app https://news.ycombinator.com/from?site=bsky.app Not sure how we can find the number of Mastodon links since it has so many domains. [2] Mastodon and Bluesky user counts: https://mastodon.social/@mastodonusercount/112131206329058510 https://mastodon.social/@mastodonusercount/11213120632905851... https://bsky.app/profile/bsky.app/post/3klzrudt4uk2z https://bsky.app/profile/bsky.app/post/3klzrudt4uk2z https://bsky.app/profile/bsky.app/post/3kkv3clm3su2h https://bsky.app/profile/bsky.app/post/3kkv3clm3su2h
perihelions 2y ago
Wait, do normal printers need gravity to work? If I were to find one and flip it upside-down, would it continue functioning normally?
- a_gnostic 2y ago
  Inkjets need a gas cartridge. https://www.spacepen.com/our-story https://www.spacepen.com/our-story
- falkenb0t 2y ago
  Not exactly a primary source but according to this thread: https://forum.nasaspaceflight.com/index.php?topic=10617.0 https://forum.nasaspaceflight.com/index.php?topic=10617.0 "Toner is held to the paper in a laser printer by electrostatic attraction (opposite charges attract), not gravity. Along those same lines, in an inkjet printer ink droplets are fired at the paper, not just dropped, so once again I doubt gravity is an issue."
  - HeyLaughingBoy 2y ago
    But before you even got to the point of printing, the paper in a regular laser or inkjet printer wouldn't even feed properly if upside down! I'm also willing to bet that whether or not the droplets are "fired" at the paper or not, the inkjet cartridges aren't going to work in an inverted position: they might not even supply ink in that configuration.
- rtkwe 2y ago
  Normal printers probably wouldn't handle the shaking of launches and the extra G forces during that which for shuttle were ~3Gs.
  - generj 2y ago
    And when shuttle was developed, printers barely existed. Both inkjet and laser desktop printers were introduced commercially 1-3 years before the shuttles first flight in 1981, and weren’t very reliable yet. Desktop printers still aren’t as reliable as a teletype or dot matrix printer. There’s a reason airlines use dot matrix for printing flight manifests at the gate. Ink plotters, teleprinters, and fax machines ruled the world. But plotters are dreadfully slow at writing text. Radio fax machines may have been viable if they were rugged enough. But they probably weighed as much as the teletype and were much slower - only real advantage is printing diagrams and photos.
eigenvalue 2y ago
This is cool but it just makes me think the Shuttle was absurdly inefficient across the board. Why waste not just the launch weight but the engineering work on making such a specialized printer? Aren’t we talking about the late 70s/ early 80s? Surely there were commercially available printers that could have been substituted that would weigh less and wouldn’t have the overheating issues. Having unlimited government money is ultimately a curse for efficiency and performance.
- wildzzz 2y ago
  It's overkill for normal office use but the space shuttle is going to have some massive vibration and mechanical shock during launch. All systems have to be ruggedized to withstand the environment. A commercial unit might not survive the trip up and building some sort of vibration damping system for it might take up more space. If the manufacturer can't guarantee the uptime for the commercial unit, they might need a spare aboard as well also in its own special dampener case. Sometimes it just makes sense to do a custom design that meets your needs instead of trying to make a square peg fit a round hole. Also the related systems have to be considered. The Shuttle had a power bus of 28VDC, were there any commercial printers that took 28VDC and had proper EMI filtering? Were commercial printers compatible with the types of data signals expected on the Shuttle? You may need to build some sort of adapter to make a commercial printer work with the data and power systems. You may end up with something just as heavy and bulky and still not as reliable.
  - dylan604 2y ago
    > It's overkill for normal office use but the space shuttle is going to have some massive vibration and mechanical shock during launch. Maybe you haven't seen how some delivery drivers treat the packages in their care. I swear I've received boxes that look like the were shaken, not stirred, to the level of a rocket launch.
    - kayodelycaon 2y ago
      Printers aren’t usually shipped in operable condition.
ajsnigrutin 2y ago
There's a much simpler version of a communications 'printer' called Hellschreiber https://en.wikipedia.org/wiki/Hellschreiber https://en.wikipedia.org/wiki/Hellschreiber Some old specimens still work, some new reproductions have been made, and it can also be simulated in software with various popular ham-radio programs. ...also, it's used by at least a few dozen hams every now and then :)
gooseyman 2y ago
TIL a space shuttle printer will fetch $8,659 at auction. https://www.rrauction.com/auctions/lot-detail/347156706649821-space-shuttle-teleprinter/?cat=0 https://www.rrauction.com/auctions/lot-detail/34715670664982...

106 points by DAddYE 2y ago

I am fascinated they used 60 pounds and a large amount of space for this teleprinter. At 30K per pound of payload that is $1.8 million per flight. Really shows how important reliable printed updates were considered. And all the flaws of the printer that were managed around - turning it off to save power and prevent it overheating with specific tones.

eddieroger 2y ago
I was pretty stuck by that, too, and it made me wonder if maybe I don't understand or underestimate the value of paper transmission. I suppose if radio communication is good but flaky, or for persistence of instruction, like procedures, then it would be good for them to be able to print. But at such a cost!
- willcipriano 2y ago
  [flagged]
  - actionfromafar 2y ago
    This is true, but in hindsight only a partial success. A good chunk of the communists weren't. :-/
    - a_gnostic 2y ago
      Communism is the very definition of failure. Return, refit, and redeploy to purge the stain of this failure with the peroxide of victory!
- krisoft 2y ago
  I guess with modern googles one would just pack an "ipad" equivalent tablet. If one worries about accidents and freak space particles disabling it give them 3. If one still worries one can develop a "space rated" tablet. But probably at those radiation levels one should also start worrying about the crew's health. But of course that is projecting our current capabilities back in time. I looked it up and the "Osborne 1" portable computer[1] was just released 9 days before the shuttle's first flight. It weighed 24.5 lb (11.1 kg) and could display 52 x 24 characters on a small CRT. So yeah, that would not be nice to read manuals with :D 1: https://en.wikipedia.org/wiki/Osborne_1 https://en.wikipedia.org/wiki/Osborne_1
  - generj 2y ago
    Right it clearly was the best choice for the time the shuttle was developed but just shows how removed from the 1960s and 70s we are today. My earlier point about payload weight was probably the wrong focus. Mission success and maximizing what the crew can accomplish in orbit are greatly facilitated by one way text from ground control, and doubtlessly paid for the 60 pounds Astronauts were already used to Telex weather reports as pilots so existing UX. And the crew specialists all had PhDs and thus were experts at reading typed paper. So no training on yet another shuttle subsystem. The teletype could be effectively shared between crew - just tear off the paper. A portable computer could only be used by one or two people, AND would need to be radiation hardened and aerospace qualified.
  - amelius 2y ago
    iPads are more hazardous than you think: https://appleinsider.com/articles/23/07/14/fatal-helicopter-crash-likely-caused-by-dropped-ipad https://appleinsider.com/articles/23/07/14/fatal-helicopter-...
    - kayodelycaon 2y ago
      Not really an iPad-specific issue. A clipboard or checklist could have done the same thing.
- dylan604 2y ago
  Maybe they remember the situation with Apollo 13 where they had no way to right down the procedures other than by hand and using space pages from the existing printed documents. You then had the issue where the guys were so fatigued and CO2 levels getting to a point of making vision blurry. I could see where that might have factored into the decision of wanting to avoid all of that with the ability of printing new/modified procedures.
  - dylan604 2y ago
    too late to edit, but right != write <hangsHeadInShame>
- shagie 2y ago
  Remember that this was also before easily portable electronics. Today you'd get a PDF and store it on your iPad. Secure it for landing and you're good. All the documents you want. In the 80s consider the "Mission Control has new landing procedures that you need to follow. Here is a 42 item check list that you'll need to do before initiating task 357 from the mission specification." How do you get that 42 item check list? Do you write it down? What that transcribed properly? Was that a P or a B that the person heard over the radio? (Yes, I know Bravo Papa). Here's a secret objective for the mission ( https://ntrs.nasa.gov/api/citations/20110023479/downloads/20110023479.pdf https://ntrs.nasa.gov/api/citations/20110023479/downloads/20... ) to preform while in orbit that has now been approved and was not part of the initial mission profile. The instructions will be printed out and are for the captain and pilots eyes only. There are a number of reasons that one may need a secure printer to handle new documents while on the Space Shuttle. With 70s and 80s tech, the approach taken is reasonable.
KineticLensman 2y ago
> I am fascinated they used 60 pounds and a large amount of space for this teleprinter. IIRC the Zion space habitat in Neuromancer had a state-of-the-art line printer which at one point spews continuous-fold paper into the weightless environment. They had however got rid of the slide-rules that were essential in early-era Arthur C Clarke spaceships
- throwanem 2y ago
  That was Haniwa, not Zion. The printer was spewing paper because someone had put a laser through its faceplate while Corto was taking the ship. Also, Haniwa is described explicitly and implicitly as an exoatmospheric luxury yacht, and thus likely wasn't designed for high acceleration. Also, I'm pretty sure it was a thermal printer, not a line printer as here. Also, Neuromancer is period-piece literary sf. So I'm not necessarily sure how relevant it is here.
  - KineticLensman 2y ago
    In terms of relevance, I was amused that real and contemporary fictional spacecraft both had paper printers
    - lsllc 2y ago
      The question is, would the craft now need help from reaction wheels to offset the inertia from the moving print head / paper feed? Or would there need to be a special version of the printer firmware that kept track of its movement so it could always impart equal but opposite inertia?
      - throwanem 2y ago
        Since a thermal printer only needs as much pressure on the platen roller as required to keep the paper registered, the roller itself could be hollow and thus carry negligible inertia. The print head could be net neutral by operating boustrophedonically, which many printers already do - both of my inkjets, for example! - and that might actually count for more, considering the possible need for some thermal mass to dissipate waste heat from the printing elements. (I don't think modern thermal printers need that, but I suppose in the 80s they might have.) Worst case, the firmware might need to ensure the number of head passes is even, I think most simply by counting print passes and if needed performing a final "return" pass with a cold head - again a common behavior, and one also displayed by both my inkjets since that avoids the need for a parking station on either side of the paper path. The line printer with its heavy drum would probably be more of a concern for the Shuttle, although I doubt a significant one. Reaction wheels function by change in angular momentum, and a line printer drum spins at a fixed rate in operation; as long as spinup and spindown take about the same time, which is easy enough to achieve, the net effect on attitude should be negligible, especially considering the entire printer constitutes only about 1/3000 of the orbiter's dry mass. You might not want to run the thing during an OMS burn, but even if you did I doubt it'd matter; assuming constant thrust from spinup through spindown, your course would be displaced proportionally to the length of the print job, but given the minimal relative inertia and that line printers typically output in the tens of hundreds of lines per second I think it'd need quite a long job to make a noticeable difference, and you'd almost certainly run out of paper long before. (Don't take any of this too seriously; I'm the wrong kind of engineer to give authoritative answers here, but the question is fun to think about anyway.)
beerandt 2y ago
The thing that immediately jumped into my head is coded military use. Especially since they mention the printer being based on a military design. It's still rather obscure, if not still secret, just to what extent we were actually using the shuttles in their intended military capacity. But when designed, the military use was expected to be much much higher than what panned out. This printer would be high on the list of the weight budget, to the point that I wonder if it wasn't critical protocol to some still secret military use, similar to the teletype nuke codes / orders on a sub. Running over the audio system also makes me curious if it was strictly unencrypted comms, or if it could plug in to a decrypted steam. Were they clear broadcasting coded messages, or encrypted-broadcast clear messages (or both or neither). IIRC, NASA used to have at least some 'private' comms with astronauts that were in the clear, but they basically just didn't rebroadcast to the public or publicize those currently used frequencies, and just sort of trusted those in the know not to listen in.
- samstave 2y ago
  [flagged]
  - dylan604 2y ago
    what a useless post and your last sentence is just made up from thin air. if you believe any of that, you probably think the earth is flat, the moon landing was shot on a film stage in hollywood. a simple web search will show the actual reasons for the shuttle disasters.
  - DaSHacka 2y ago
    > I think Challenger was sabotage Mind explaining your reasoning? As someone not very familiar with the details, I'm curious
    - samstave 2y ago
      As much as Dylan wants to denegrate my post: I have always believed the Shuttle was sabotaged. I watched it live when it happened when I was a kid and followed all aspect from the lead up (we voted for Kristy in my school IIRC) -- but there has always been a lot of weird strangeness about the shuttle and the demise of its occupants. Ant to Dylan - relax - I can speculatively hold dystopian-sci-fi what-ifs without your other slanders. Its a fun and more entertaining topic than most movies. I said I do not know what happened, I said I believe the challenger was sabotaged, with my disclaimer that I do not know. The theories about the astronauts being alive are silly but well crafted fiction. Dylan got triggered a bit to hard by my comments. -- The reason I feel the challenger was sabotaged is also backed up by CIA documents: https://i.imgur.com/ylDBcDH.png https://i.imgur.com/ylDBcDH.png https://www.cia.gov/readingroom/docs/CIA-RDP88B00443R001904460005-6.pdf https://www.cia.gov/readingroom/docs/CIA-RDP88B00443R0019044... But Ill let Dylan do his own research. >Plus "do his own research" is awfully adjacent to the Q-unacy. That was the joke, jeasus. as he is the one accusing me of being flat-earth moon denier. Read the linked PDF from the CIA FFS. Its a fun theory and that has multiple articles linked from the 80s. So a "simple web search" of shit that went down in the decades before the internet isnt as simple, nor reliable as one would hope. However - I am sure Dylan Called Google and knows all about it.
tyingq 2y ago
Here's my guess. Government bureaucracy is probably very high for anything space related. So "based on the military's AN/UGC-74" could have helped get it through approvals. It would have ticked a lot of boxes for ruggedized parts, use in harsh environments, and so on.
- beerandt 2y ago
  I don't doubt that for a second- but I'm more curious about the requirement for some kind of printout in the first place. Especially since it ultimately ended up weighing what it did. Military/ Ruggedized is a smart choice for a printer that needs to go through that environment, no matter the why. I'm more interested in what it tells us about the underlying purpose (or what it might rule out, like the part about wired directly into unencrypted comms).
  - tyingq 2y ago
    Oh, I didn't consider that, since I was a young person then. Sticking notes, directives, etc, everywhere was just really common. So if they get a note about extra daily checks on equipment X, they print/affix the note to the equipment. Or other similar needs. There would probably be limited screens, so anything you wanted to be known to everyone, becomes a note.
  - jcrawfordor 2y ago
    I don't think the requirement for printed output requires any appeal to military applications. They would have been exchanging navigation information with mission control over the radio. That's all mission critical and needs to be read back. Anything they got via voice they would have to write down. Getting it by text in the first place would increase reliability and reduce cockpit workload. You also get in-flight information like weather that you'll want to write down for later reference. Teleprinter writes it for you so you can review it at your leisure. Airliners and ships at sea have both historically used teleprinters for the same reasons, although the modern navigation computers have mostly eliminated the need.
amelius 2y ago
> At 30K per pound of payload that is $1.8 million per flight. Yeah, but they could save by using white-label ink cartridges.

marcodiego 2y ago

X (twitter) is useless for threads unless you're logged in. How can I read this thread?

ghosty141 2y ago
Yeah somebody should mirror it. In general I dont understand why people post things like this on X. Its a horrible platform.
- bookofjoe 2y ago
  For some; for technically dumb people like me, it's the only platform that's easy to use.
- bagels 2y ago
  What are some better alternatives?
  - omoikane 2y ago
    Current best answer seem to be Mastodon and Bluesky. If we are going by the number of users, Facebook has more users than Twitter and Threads has about the same order of magnitude, but we still see a lot more Twitter submissions to HN compared to Facebook and Threads[1]. If users prefer the microblog format, Mastodon and Bluesky appear to be the most compelling alternatives, both have been steadily gaining users[2]. [1] Submissions from various sites: https://news.ycombinator.com/from?site=twitter.com https://news.ycombinator.com/from?site=twitter.com https://news.ycombinator.com/from?site=threads.net https://news.ycombinator.com/from?site=threads.net https://news.ycombinator.com/from?site=facebook.com https://news.ycombinator.com/from?site=facebook.com https://news.ycombinator.com/from?site=bsky.app https://news.ycombinator.com/from?site=bsky.app Not sure how we can find the number of Mastodon links since it has so many domains. [2] Mastodon and Bluesky user counts: https://mastodon.social/@mastodonusercount/112131206329058510 https://mastodon.social/@mastodonusercount/11213120632905851... https://bsky.app/profile/bsky.app/post/3klzrudt4uk2z https://bsky.app/profile/bsky.app/post/3klzrudt4uk2z https://bsky.app/profile/bsky.app/post/3kkv3clm3su2h https://bsky.app/profile/bsky.app/post/3kkv3clm3su2h

perihelions 2y ago

Wait, do normal printers need gravity to work? If I were to find one and flip it upside-down, would it continue functioning normally?

a_gnostic 2y ago
Inkjets need a gas cartridge. https://www.spacepen.com/our-story https://www.spacepen.com/our-story
falkenb0t 2y ago
Not exactly a primary source but according to this thread: https://forum.nasaspaceflight.com/index.php?topic=10617.0 https://forum.nasaspaceflight.com/index.php?topic=10617.0 "Toner is held to the paper in a laser printer by electrostatic attraction (opposite charges attract), not gravity. Along those same lines, in an inkjet printer ink droplets are fired at the paper, not just dropped, so once again I doubt gravity is an issue."
- HeyLaughingBoy 2y ago
  But before you even got to the point of printing, the paper in a regular laser or inkjet printer wouldn't even feed properly if upside down! I'm also willing to bet that whether or not the droplets are "fired" at the paper or not, the inkjet cartridges aren't going to work in an inverted position: they might not even supply ink in that configuration.
rtkwe 2y ago
Normal printers probably wouldn't handle the shaking of launches and the extra G forces during that which for shuttle were ~3Gs.
- generj 2y ago
  And when shuttle was developed, printers barely existed. Both inkjet and laser desktop printers were introduced commercially 1-3 years before the shuttles first flight in 1981, and weren’t very reliable yet. Desktop printers still aren’t as reliable as a teletype or dot matrix printer. There’s a reason airlines use dot matrix for printing flight manifests at the gate. Ink plotters, teleprinters, and fax machines ruled the world. But plotters are dreadfully slow at writing text. Radio fax machines may have been viable if they were rugged enough. But they probably weighed as much as the teletype and were much slower - only real advantage is printing diagrams and photos.

eigenvalue 2y ago

This is cool but it just makes me think the Shuttle was absurdly inefficient across the board. Why waste not just the launch weight but the engineering work on making such a specialized printer? Aren’t we talking about the late 70s/ early 80s? Surely there were commercially available printers that could have been substituted that would weigh less and wouldn’t have the overheating issues. Having unlimited government money is ultimately a curse for efficiency and performance.

wildzzz 2y ago
It's overkill for normal office use but the space shuttle is going to have some massive vibration and mechanical shock during launch. All systems have to be ruggedized to withstand the environment. A commercial unit might not survive the trip up and building some sort of vibration damping system for it might take up more space. If the manufacturer can't guarantee the uptime for the commercial unit, they might need a spare aboard as well also in its own special dampener case. Sometimes it just makes sense to do a custom design that meets your needs instead of trying to make a square peg fit a round hole. Also the related systems have to be considered. The Shuttle had a power bus of 28VDC, were there any commercial printers that took 28VDC and had proper EMI filtering? Were commercial printers compatible with the types of data signals expected on the Shuttle? You may need to build some sort of adapter to make a commercial printer work with the data and power systems. You may end up with something just as heavy and bulky and still not as reliable.
- dylan604 2y ago
  > It's overkill for normal office use but the space shuttle is going to have some massive vibration and mechanical shock during launch. Maybe you haven't seen how some delivery drivers treat the packages in their care. I swear I've received boxes that look like the were shaken, not stirred, to the level of a rocket launch.
  - kayodelycaon 2y ago
    Printers aren’t usually shipped in operable condition.

ajsnigrutin 2y ago

There's a much simpler version of a communications 'printer' called Hellschreiber https://en.wikipedia.org/wiki/Hellschreiber https://en.wikipedia.org/wiki/Hellschreiber Some old specimens still work, some new reproductions have been made, and it can also be simulated in software with various popular ham-radio programs. ...also, it's used by at least a few dozen hams every now and then :)

gooseyman 2y ago

TIL a space shuttle printer will fetch $8,659 at auction. https://www.rrauction.com/auctions/lot-detail/347156706649821-space-shuttle-teleprinter/?cat=0 https://www.rrauction.com/auctions/lot-detail/34715670664982...