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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 receive

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
  Isn’t this only the case if the intent is for a range officer to abort? I.e., if this system is fully autonomous and on-board, a receiver wouldn’t be necessary?
  - gbrown 6y ago
    Yes
  - qubex 6y ago
    What the OP seems to be saying is that the emergency abort system actually operates on a “lysine deficiency” basis: if the signal is no longer received, the self-destruct system goes BOOM. I suppose this classifies as “fail-safe”, though if there’s folks riding on the tip of this large sharp shard with the explosive force of a small nuclear weapon I’d be rather concerned about radio transient interference and things like that.
    - deleted 6y ago
      [deleted]
    - bumby 6y ago
      In that case, is it not really autonomous? Who’s stopping the signal? I’m assuming the range officer? When passengers are on-board, there’s generally a launch abort engine that is supposed to help them leave safely in a abort scenario
- SEJeff 6y ago
  The way the automated FTS works is essentially that the USAF blasts a "DO NOT BLOW UP" signal with a very high power transmitter to the FTS. If the FTS doesn't receive that signal, it triggers and then you have a RUD.
  - gbrown 6y ago
    That sounds terrifying

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
Isn’t this only the case if the intent is for a range officer to abort? I.e., if this system is fully autonomous and on-board, a receiver wouldn’t be necessary?
- gbrown 6y ago
  Yes
- qubex 6y ago
  What the OP seems to be saying is that the emergency abort system actually operates on a “lysine deficiency” basis: if the signal is no longer received, the self-destruct system goes BOOM. I suppose this classifies as “fail-safe”, though if there’s folks riding on the tip of this large sharp shard with the explosive force of a small nuclear weapon I’d be rather concerned about radio transient interference and things like that.
  - deleted 6y ago
    [deleted]
  - bumby 6y ago
    In that case, is it not really autonomous? Who’s stopping the signal? I’m assuming the range officer? When passengers are on-board, there’s generally a launch abort engine that is supposed to help them leave safely in a abort scenario
SEJeff 6y ago
The way the automated FTS works is essentially that the USAF blasts a "DO NOT BLOW UP" signal with a very high power transmitter to the FTS. If the FTS doesn't receive that signal, it triggers and then you have a RUD.
- gbrown 6y ago
  That sounds terrifying