Earlier quoted context omitted.
SSH into the rocket and restart services?
> kubectl rollout restart deploy spacex-falcon9
> kill -9 1
Receiving SpaceX Falcon 9 Telemetry with a HackRF and 1.2m Satellite Dish
101–110 of 114 posts
Re: Receiving SpaceX Falcon 9 Telemetry with a HackRF and 1.2m Satellite Dish
#102Earlier quoted context omitted.
Well yeah, but the actors that can overcome that barrier are likely the ones you're most worried about in the first place. So maybe it limits number of adverse actors that can attempt anything, but it doesn't allow you any shortcuts in system design/security. I've always assumed that frequency barrier stuff was more about defense against tactical, air based electronic jamming/countermeasures. ETA: Thinking about it s…
Obscurity is about hiding amongst the noise. I describe physical network separation, essentially air-gapping. Do we encrypt the signal between a car's brake pedal and the brakes? Why not? It is a very important network that could result in loss of life. We don't encrypt because the network is physically separate from attackers. If they are tapping into your car's internal wiring then they could kill you in any number…
>We don't encrypt because the network is physically separate from attackers.
Given the existence in modern vehicles of:
- a shared bus for communication amongst the processing units
- autonomous emergency braking being fairly standard
and
- network connectivity being available in some cases
I think your analogy might be outdated.
Re: Receiving SpaceX Falcon 9 Telemetry with a HackRF and 1.2m Satellite Dish
#103Earlier quoted context omitted.
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.
That sounds terrifying
True, but it’s the safest configuration because you want the default condition to abort. The inverse set up is less safe because there are more failure modes for a receiver to break, meaning if a abort command was sent there’s more chance it won’t respond. It’s like choosing a normally-open or normally-closed valve; you want the default (power off) configuration to be the safer one. Inadvertently aborting is safer than not aborting when you should have
Re: Receiving SpaceX Falcon 9 Telemetry with a HackRF and 1.2m Satellite Dish
#104Earlier quoted context omitted.
The launch termination system at least needs a receiver
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.
RUD: Rapid Unscheduled Dissassembly
Re: Receiving SpaceX Falcon 9 Telemetry with a HackRF and 1.2m Satellite Dish
#105Earlier quoted context omitted.
The launch termination system at least needs a receiver
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?
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.
Re: Receiving SpaceX Falcon 9 Telemetry with a HackRF and 1.2m Satellite Dish
#106Earlier quoted context omitted.
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?
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…
[deleted]
Re: Receiving SpaceX Falcon 9 Telemetry with a HackRF and 1.2m Satellite Dish
#107Earlier quoted context omitted.
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.
The launch termination system at least needs a receiver
It does not. F9 FTS is onboard and entirely automated. There is no ground trigger.
Re: Receiving SpaceX Falcon 9 Telemetry with a HackRF and 1.2m Satellite Dish
#108Earlier quoted context omitted.
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
> The override is missing the droneship or blowing itself up. What if "missing the drone ship" means "hitting Chicago"? I'm somewhat surprised to hear that there may not be a functional remote abort mechanism.
> What if "missing the drone ship" means "hitting Chicago"?
It doesn't and never will. The rocket is never on a trajectory that will hit Chicago (or any other populated area). The splashdown point of the ballistic trajectory is always over the ocean, until the final burn puts it on the drone ship or landing pad. If that burn doesn't happen for whatever reason, it crashes in the ocean (and that has happened in the past).
Re: Receiving SpaceX Falcon 9 Telemetry with a HackRF and 1.2m Satellite Dish
#109Earlier quoted context omitted.
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?
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…
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
Re: Receiving SpaceX Falcon 9 Telemetry with a HackRF and 1.2m Satellite Dish
#110Earlier quoted context omitted.
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...
Those same notes mention that the flight termination system was unencrypted. Now it's autonomous.
More info on AFSS.
https://www.spaceflightinsider.com/space-centers/ccafs/autom...