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Some sleuths repaired/decoded a corrupted video file from (the first?) splashdown of a Falcon 9 in the ocean a few years ago [0], so maybe someone is able to te

Some sleuths repaired/decoded a corrupted video file from (the first?) splashdown of a Falcon 9 in the ocean a few years ago [0], so maybe someone is able to tease out some information from the recorded binary data as well? They only searched for obvious string data so far. It's a different beast of course, as the structure and meaning of the data is basically unknown in contrast to the known format of a video file. Maybe some meanings can be inferred, let's say that a value in the possible range of rpms of a turbopump is correlated with acceleration or so? [0] https://www.nasaspaceflight.com/2014/06/recovering-falcon-9-ocean-landing-video-done/ https://www.nasaspaceflight.com/2014/06/recovering-falcon-9-...

Cthulhu_ 6y ago
I'm kinda hoping they'll publish some specs about at least part of their transmission data, I mean given that it's not encrypted either means it's not critical, or encryption is too costly. I can imagine that commands the other way do have some kind of encryption.
- TeMPOraL 6y ago
  I'd assume so. It's standard practice with space hardware to keep the downlink unencrypted, and secure just the command channel. Saves on complexity and power use (the latter matters a lot for satellites).
- sandworm101 6y ago
  >> commands the other way do have some kind of encryption. I'm betting that they don't. The reason that this stuff isn't encrypted is likely the same reason that fighter jets and airliners don't have keys. Yes, someone could jump in and do something bad, but the greater danger is the encryption/lock system causing an accident by getting in the way of legitimate commands. This is the launch vehicle, not the spy satellite. It is likely that physical realities offer sufficient protection. The rocket might be designed to ignore commands coming from the wrong direction and/or signal strength. It might be that to send a command you would have to be physically co-located with the legitimate antenna array, or be ridiculously more powerful, something that would be very easy to detect.
  - coder543 6y ago
    > Yes, someone could jump in and do something bad, but the greater danger is the encryption/lock system causing an accident by getting in the way of legitimate commands. That's just not how encryption works... Also, a malicious actor being able to point a multi-ton rocket filled with explosive fuel the wrong direction would be far worse than the system continuing the mission autonomously. Now imagine human spaceflight missions where the command stream can be hijacked by anyone with an SDR. Yeah, not happening. The command stream better be authenticated, and if you're doing cryptographic message authentication, you might as well encrypt the payload so no one else can read it anyways. > The rocket might be designed to ignore commands coming from the wrong direction and/or signal strength. You want to talk about something error prone "getting in the way of legitimate commands"? That would be an unbelievably error prone approach. Oh, the rocket accidentally rolled on its axis a few degrees? Ignore all commands to correct it! Encryption and authentication are extremely reliable.
    - sandworm101 6y ago
      >> spaceflight missions where the command stream can be hijacked by anyone with an SDR. Yeah, not happening. An SDR attached to some serious antenna hardware, enough to get into the sidelobe of an antenna pointed at the legitimate command network. As for rockets rolling, that isn't handled by ground commands. That sort of stuff it totally within the rocket's internal systems. The ground staff have very little control until the second stage has done its thing.
    - zelon88 6y ago
      > Now imagine human spaceflight missions where the command stream can be hijacked by anyone with an SDR. Yeah, not happening. I am no expert on spacecraft command channels but I would highly doubt that a lot of non military US spacecraft use encrypted command signals until extremely recently. He is right. Space engineers are extremely adverse to trying new technology and technique. They are even more adverse to adding code to things that work without adding more code. In order to talk to one of these things you have to have one of the satellites in the NASA DTN. Technically the DTN protocol supports authentication and encryption but remember that everything about DTN must maintain perfect backwards compatibility with space assets that are made with decades old technology. Security is not it's primary goal like with terrestrial communications. Connectivity is far more important.
- Denvercoder9 6y ago
  > that commands the other way Does Falcon 9 even have a command channel anymore? The trajectory is preprogrammed, guidance and control is automatic, and the flight termination system is automatic as well.
  - ClumsyPilot 6y ago
    People who code still make mistakes. There's got to be an override of some sort
    - NikolaeVarius 6y ago
      The override is missing the droneship or blowing itself up. Why the hell does there "got" to be an override. Humans are generally not good at doing hypersonic/supersonic aerodynamic modeling in their heads, especially remotely
      - matmatmatmat 6y ago
        `The override is missing the droneship or blowing itself up.` Disagree, that's not an override. That's a program written by a human programmer (who makes mistakes) that autonomously decides that something went wrong. I would argue there has "got" to be an override precisely because humans make mistakes all the time and so there's no reason to think that an autonomous failsafe should work in all possible situations. I don't know much about rocketry, but if it's true that there's no remote abort capability, that seems like a deeply misguided decision.
        NikolaeVarius 6y ago
        >> I don't know much about rocketry There you go. You are welcome to try and disagree with decades of rocket launch practices. The range safety officer can blow up the rocket if the rocket veers off and is in danger of overshooting the safe area. Otherwise, you know the reason why we launch over water? Since it doesn't goddamn matter after it clears the tower and clears the danger zone. It either blows up over water, and who cares, it lands in the water, who cares, or it blows up in the upper atmosphere, and who cares. Also, the rocket blowing itself up is a reference to the fact that if it is going off course, there is damn good chance it will destroy itself since aerodynamic forces are calculated to a specific launch window with upper weather. If not following a calculated path, good chance it will rip itself apart. Also many abort modes are disabled for the first few seconds in flight so a dumb human or computer wont accidentally trigger a abort after flight starts and blow up the launch pad
- jccooper 6y ago
  There are no commands the other way. F9 flies entirely autonomous, including termination. Based on the FCC filings, I'm pretty sure it doesn't even have receivers.
  - darknavi 6y ago
    There was a reddit thread from a guest lecture a few years ago that said that around T-1 they turn off all receivers on Falcon 9. https://www.reddit.com/r/spacex/comments/lw6yk1/notes_from_a_talk_given_by_then_head_of_software/ https://www.reddit.com/r/spacex/comments/lw6yk1/notes_from_a...
    - outworlder 6y ago
      Those same notes mention that the flight termination system was unencrypted. Now it's autonomous.
      - toomuchtodo 6y ago
        More info on AFSS. https://www.spaceflightinsider.com/space-centers/ccafs/automated-flight-safety-improving-space-access/ https://www.spaceflightinsider.com/space-centers/ccafs/autom...
  - bumby 6y ago
    I know the Air Force claims this makes it safer by avoiding the need for a range officer to make a time sensitive safety call but it’s not like there isn’t a precedent of software goofs in this area of software controlled termination https://apnews.com/article/1d85f290e31cad8532636fcb576f4788 https://apnews.com/article/1d85f290e31cad8532636fcb576f4788
  - gbrown 6y ago
    The launch termination system at least needs a receiver
    - bumby 6y ago
- eeZah7Ux 6y ago
  you are confusing encryption and signing
drmpeg 6y ago
Video decoded here. https://twitter.com/r2x0t/status/1370030702633312259 https://twitter.com/r2x0t/status/1370030702633312259
- jcims 6y ago
  Not sure about @r2x0t but @uhf_satcom is involved in some pretty amazing space rf projects, poke around their tweet history. Some crazy smart folks out there.
- soapboxrocket 6y ago
  I'm interested in the ITAR implications here of the video. When asked about seeing the inside of the fuel tank during the crew demo mission Shotwell said no because it was covered by ITAR. This video clearly shows inside a tank.
  - schiffern 6y ago
    Shotwell's comments are surprising since SpaceX has publicly shown that same interior tank camera view many times on previous webcasts. I wonder if something was different about the demo mission?

Cthulhu_ 6y ago

I'm kinda hoping they'll publish some specs about at least part of their transmission data, I mean given that it's not encrypted either means it's not critical, or encryption is too costly. I can imagine that commands the other way do have some kind of encryption.

TeMPOraL 6y ago
I'd assume so. It's standard practice with space hardware to keep the downlink unencrypted, and secure just the command channel. Saves on complexity and power use (the latter matters a lot for satellites).
sandworm101 6y ago
>> commands the other way do have some kind of encryption. I'm betting that they don't. The reason that this stuff isn't encrypted is likely the same reason that fighter jets and airliners don't have keys. Yes, someone could jump in and do something bad, but the greater danger is the encryption/lock system causing an accident by getting in the way of legitimate commands. This is the launch vehicle, not the spy satellite. It is likely that physical realities offer sufficient protection. The rocket might be designed to ignore commands coming from the wrong direction and/or signal strength. It might be that to send a command you would have to be physically co-located with the legitimate antenna array, or be ridiculously more powerful, something that would be very easy to detect.
- coder543 6y ago
  > Yes, someone could jump in and do something bad, but the greater danger is the encryption/lock system causing an accident by getting in the way of legitimate commands. That's just not how encryption works... Also, a malicious actor being able to point a multi-ton rocket filled with explosive fuel the wrong direction would be far worse than the system continuing the mission autonomously. Now imagine human spaceflight missions where the command stream can be hijacked by anyone with an SDR. Yeah, not happening. The command stream better be authenticated, and if you're doing cryptographic message authentication, you might as well encrypt the payload so no one else can read it anyways. > The rocket might be designed to ignore commands coming from the wrong direction and/or signal strength. You want to talk about something error prone "getting in the way of legitimate commands"? That would be an unbelievably error prone approach. Oh, the rocket accidentally rolled on its axis a few degrees? Ignore all commands to correct it! Encryption and authentication are extremely reliable.
  - sandworm101 6y ago
    >> spaceflight missions where the command stream can be hijacked by anyone with an SDR. Yeah, not happening. An SDR attached to some serious antenna hardware, enough to get into the sidelobe of an antenna pointed at the legitimate command network. As for rockets rolling, that isn't handled by ground commands. That sort of stuff it totally within the rocket's internal systems. The ground staff have very little control until the second stage has done its thing.
  - zelon88 6y ago
    > Now imagine human spaceflight missions where the command stream can be hijacked by anyone with an SDR. Yeah, not happening. I am no expert on spacecraft command channels but I would highly doubt that a lot of non military US spacecraft use encrypted command signals until extremely recently. He is right. Space engineers are extremely adverse to trying new technology and technique. They are even more adverse to adding code to things that work without adding more code. In order to talk to one of these things you have to have one of the satellites in the NASA DTN. Technically the DTN protocol supports authentication and encryption but remember that everything about DTN must maintain perfect backwards compatibility with space assets that are made with decades old technology. Security is not it's primary goal like with terrestrial communications. Connectivity is far more important.
Denvercoder9 6y ago
> that commands the other way Does Falcon 9 even have a command channel anymore? The trajectory is preprogrammed, guidance and control is automatic, and the flight termination system is automatic as well.
- ClumsyPilot 6y ago
  People who code still make mistakes. There's got to be an override of some sort
  - NikolaeVarius 6y ago
    The override is missing the droneship or blowing itself up. Why the hell does there "got" to be an override. Humans are generally not good at doing hypersonic/supersonic aerodynamic modeling in their heads, especially remotely
    - matmatmatmat 6y ago
      `The override is missing the droneship or blowing itself up.` Disagree, that's not an override. That's a program written by a human programmer (who makes mistakes) that autonomously decides that something went wrong. I would argue there has "got" to be an override precisely because humans make mistakes all the time and so there's no reason to think that an autonomous failsafe should work in all possible situations. I don't know much about rocketry, but if it's true that there's no remote abort capability, that seems like a deeply misguided decision.
      - NikolaeVarius 6y ago
        >> I don't know much about rocketry There you go. You are welcome to try and disagree with decades of rocket launch practices. The range safety officer can blow up the rocket if the rocket veers off and is in danger of overshooting the safe area. Otherwise, you know the reason why we launch over water? Since it doesn't goddamn matter after it clears the tower and clears the danger zone. It either blows up over water, and who cares, it lands in the water, who cares, or it blows up in the upper atmosphere, and who cares. Also, the rocket blowing itself up is a reference to the fact that if it is going off course, there is damn good chance it will destroy itself since aerodynamic forces are calculated to a specific launch window with upper weather. If not following a calculated path, good chance it will rip itself apart. Also many abort modes are disabled for the first few seconds in flight so a dumb human or computer wont accidentally trigger a abort after flight starts and blow up the launch pad
jccooper 6y ago
There are no commands the other way. F9 flies entirely autonomous, including termination. Based on the FCC filings, I'm pretty sure it doesn't even have receivers.
- darknavi 6y ago
  There was a reddit thread from a guest lecture a few years ago that said that around T-1 they turn off all receivers on Falcon 9. https://www.reddit.com/r/spacex/comments/lw6yk1/notes_from_a_talk_given_by_then_head_of_software/ https://www.reddit.com/r/spacex/comments/lw6yk1/notes_from_a...
  - outworlder 6y ago
    Those same notes mention that the flight termination system was unencrypted. Now it's autonomous.
    - toomuchtodo 6y ago
      More info on AFSS. https://www.spaceflightinsider.com/space-centers/ccafs/automated-flight-safety-improving-space-access/ https://www.spaceflightinsider.com/space-centers/ccafs/autom...
- bumby 6y ago
  I know the Air Force claims this makes it safer by avoiding the need for a range officer to make a time sensitive safety call but it’s not like there isn’t a precedent of software goofs in this area of software controlled termination https://apnews.com/article/1d85f290e31cad8532636fcb576f4788 https://apnews.com/article/1d85f290e31cad8532636fcb576f4788
- gbrown 6y ago
  The launch termination system at least needs a receiver
  - bumby 6y ago
eeZah7Ux 6y ago
you are confusing encryption and signing

drmpeg 6y ago

Video decoded here. https://twitter.com/r2x0t/status/1370030702633312259 https://twitter.com/r2x0t/status/1370030702633312259

jcims 6y ago
Not sure about @r2x0t but @uhf_satcom is involved in some pretty amazing space rf projects, poke around their tweet history. Some crazy smart folks out there.
soapboxrocket 6y ago
I'm interested in the ITAR implications here of the video. When asked about seeing the inside of the fuel tank during the crew demo mission Shotwell said no because it was covered by ITAR. This video clearly shows inside a tank.
- schiffern 6y ago
  Shotwell's comments are surprising since SpaceX has publicly shown that same interior tank camera view many times on previous webcasts. I wonder if something was different about the demo mission?