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Author here if anyone has questions about obscure 1960s technology...

• deleted 4y ago
  [deleted]
• x5x 4y ago
  First of all, good work on the reverse engineering! A more general question - What's the hardest part about reverse engineering technology from the 1960's and such, from your experience? Cheers from a former Avionics Technician. Keep up the good work, and love your blog.
  • kens 4y ago
    I'd say that RF stuff is pretty much mysterious so I generally avoid it. For instance, part of the Apollo stuff had a frequency multiplier. We opened it up and it was essentially an empty box with adjustable pegs inside. I don't want to deal with that sort of magic nonsense :-) Another hard part is things that are encased in epoxy or welded shut. In this case I used X-rays but its generally a problem. Overall, the main secret of reverse engineering old stuff is to spend way more time on it than an sensible person would.
    • naikrovek 4y ago
      > Overall, the main secret of reverse engineering old stuff is to spend way more time on it than [any] sensible person would. quote of the week. so many things have been laid bare to me by just putting in the time. even just staring at the thing(s) will often help me realize something important, somehow.
• ThePowerOfFuet 4y ago
  You will never not get an upvote from me. Thank you for everything that you do. I've been hooked since your USB power supply teardowns!
  • kens 4y ago
    Skimming the comments, I missed the word "not" and wondered what I had done to offend you :-)
• TedDoesntTalk 4y ago
  > Onboard the Command Module, these messages were decoded by the Up-Data Link Do you think there was any kind of primitive authentication of the received PSK signal? Even something as simple validating a preamble against a hard-code bit sequence?
  • kens 4y ago
    There was error checking, but not security. Each bit was expanded to a 5-bit sequence, so bit errors could be detected. The message started with a 3-bit vehicle address, so separate messages could be delivered to the Command Module and the Lunar Module. For the range safety officer's destruct control, NASA did use cryptographic security because they wanted to make sure the Russians couldn't blow up the spacecraft. This was an entirely separate system. The control unit used a secret plug that encoded the "key", that was installed just before launch so nobody could spoof the command.
    • TedDoesntTalk 4y ago
      > For the range safety officer's destruct control What was this? Never heard of it. Anywhere I can read about it? It was a remote controlled destruct??
      • kens 4y ago
        Yes, the Range Safety Officer could send a coded command to "terminate the flight of an erratic vehicle" by cutting off the engine and "dispersing the propellant". Each of the three stages in the Saturn V rocket had linear shaped charges to blow up the liquid hydrogen and liquid oxygen tanks. [1] The astronauts would hopefully be pulled to safety by the launch escape system, the rocket engine on the top of the capsule. [1] See https://history.nasa.gov/afj/ap10fj/pdf/19700015780_as-505-a10-saturn-v-technical-info-summary.pdf https://history.nasa.gov/afj/ap10fj/pdf/19700015780_as-505-a... pages 14-15.
      • jffry 4y ago
        NASA has a page with lots of info about their range safety program: https://kscsma.ksc.nasa.gov/RangeSafety https://kscsma.ksc.nasa.gov/RangeSafety And yes the rockets had shape charges in each stage which can be activated to destroy the rocket in a controlled fashion. If you have a rocket gone haywire, it's better to jettison the crew capsule to safety and do a controlled demolition, to prevent the rocket from flying out of control and crashing into structures or people on the ground. This is also why rocket launch sites tend to be coastal locations with ocean to the east - there's a lot less valuable stuff under their flight path.
• grishka 4y ago
  Your website still doesn't load from Russia. Yes, the war is indeed absolutely unacceptable, except regular people like me have exactly zero means of influencing it. Your blocking of Russian IPs thus achieves nothing but frustration. Please consider unblocking.
  • behringer 4y ago
    You could purchase a VPN that (for example) supports the Ukrainian effort. There's always something that can be done.
• WalterBright 4y ago
  What a marvelous read. Thank you!
• orbital-decay 4y ago
  I know you reverse engineer electronic devices, but I'd love to see the low-tech side of the Apollo missions. Astronauts had substantial ability to navigate in an old-fashioned way in case of equipment failure. The landing point designator on the Lunar Module window, all these elaborate procedures baked into the sequence like the roll maneuver to visually confirm the trajectory and the landing spot etc. A lot of thought went into that. If I'm not mistaken, they also had a direct need for this during Apollo 13 pre-reentry orientation. It's sometimes fun to imagine the alternative reality where miniaturization never happened and spaceflight is forced to use low-tech navigation aids - precise clock, periscopes, reticles, slide rules, nomograms. (and communication with the flight control center which does the bulk of the computational work)
  • rwmj 4y ago
    http://www.amazon.co.uk/Apollo-Springer-Praxis-Books-Exploration/dp/0387716750/ http://www.amazon.co.uk/Apollo-Springer-Praxis-Books-Explora... Excellent book on this topic.
• colejohnson66 4y ago
  How long until you reverse engineer the entirety of the Apollo modules? /s A more serious question: why'd you use an X-ray instead of cracking one open?
  • kens 4y ago
    Cracking a module open is destructive. The goal is to get the box working and breaking components doesn't help.