Space Shuttle teleprinter reverse engineering(twitter.com) |
Space Shuttle teleprinter reverse engineering(twitter.com) |
And all the flaws of the printer that were managed around - turning it off to save power and prevent it overheating with specific tones.
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.
[1] https://radionerds.com/images/e/e0/TM_11-5815-602-24.pdf#pag...
My assumption is that the decryption happened upstream of the teleprinter- the teleprinter was definitely chosen because they thought it would be useful to print things for all missions, not because it provided special encryption for military purposes. When they did classified stuff everything was encrypted.
Basically, printers are really useful. They are heavy and they can break, but are tremendously useful.
a significant portion of the funding for the shuttle came from the USAF, and one of its capabilities (to capture and return a large satellite) was a USAF requirement. They even went as far as building an entire launch pad for it at Vandenberg, which came very close to being used.
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).
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
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.
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/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.
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
Yeah, but they could save by using white-label ink cartridges.
https://www.rrauction.com/auctions/lot-detail/34715670664982...
"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."
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.
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.
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 :)
(I assume it's the same post, couldn't read the one on twitter)
Please don't complain about tangential annoyances—e.g. article or website formats, name collisions, or back-button breakage. They're too common to be interesting.
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.
A lot of the cost for space bound items are from R&D being concentrated in a few items but others are because it costs a lot to make sure they're not going fail or kill someone. Using this behemoth saves some of the time by reusing a military line printer that was likely already tested for shock resistance if it was used on ships and for fire safety for similar reasons.
There's also the potential military uses of the Shuttle which informed a lot of it's design. Military printer already has the decoding infrastructure if it needs to be built in with known key management etc you'd have to build seprately for a commercial printer.
[1] https://ui.adsabs.harvard.edu/abs/1982ntc..confR...4S/abstra...
https://topics.libra.titech.ac.jp/recordID/catalog.bib/BA902...
Your idea of how electromechanical devices "just work" is based on office environments (and even there they fail with astounding regularity today, half a century later).
As an electrical engineer that has repaired many (also very old) devices I don't think you have a realistic idea of why the thing looks as it does. One point is environmental factors (strong vibration, harsh radiation, potential temperature differences etc) another one is risk managment. If your commercial printer fails, how will it fail? You better know exactly what it's failure modes are, because you are the guy who selected that printer and you are reaponsible for both the failure of the mission and the potential death of astronauts who trust you. Still feel secure about the choice? Then you are probably the wrong person for the job.q
TL;DR: look for a certain (recent) submarine failure to see how well your approach works in practise
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.
The posts about the System/360 consoles come to mind, for example. I’m not sure how “popular” those were(?), but they’ve been very helpful as references for an art project I’m working on!
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=threads.net
https://news.ycombinator.com/from?site=facebook.com
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/11213120632905851...
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.
https://appleinsider.com/articles/23/07/14/fatal-helicopter-...
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.)