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There are four parachutes. It's designed to support at least a single-chute failure, I don't know about multiple chute outages. As for propulsive landing - th

There are four parachutes. It's designed to support at least a single-chute failure, I don't know about multiple chute outages. As for propulsive landing - the latest I can see[1] is that while the craft is technically capable of propulsive landing, it's not approved by NASA, even for emergencies. So it's likely that these options are not even available for the crew, and they wouldn't have trained on how to use it/activate it. [1] https://www.teslarati.com/spacex-crew-dragon-emergency-landing/ https://www.teslarati.com/spacex-crew-dragon-emergency-landi...

sebazzz 6y ago
Not even for emergencies? Does that mean that it is officially not there, but in the unlikely unlikely event it can be used, or that it really isn't there anymore and the capsule would just drop dead on the ground?
- anticensor 6y ago
  It is there, just not certified for this use. However, if they manage to make a successful ememgency propulsive landing (even an unaccounted one), it will be investigated and then approved post-facto. The engines used for landing are the same engines that are used for post-second-stage maneuvreing.
- Kliment 6y ago
  It means it's never been tested and there's no safe way to use it - the hardware and software are not configured to have that ability for this particular flight, is how I understand it.
- paranoidrobot 6y ago
  > Not even for emergencies? Clearly not. NASA was already not keen about the superdraco system. The explosion that destroyed the Dragon 2 capsule that was slated for the In-flight Abort test killed any chance of it being used for human-rated flights. > Does that mean that it is officially not there This is life-critical hardware/software. You don't go putting functionality in there that isn't approved by NASA, and most importantly the crew who're going to fly it. Finding out that there's undocumented features and easter-eggs, even if they might in some very remote scenario help save life is certain to be outweighed by the risk that having it in there might somehow contribute to someone's death. Could it be used for propulsive landing? Perhaps, but they'll first have to prove to NASA that it's safe - just like they proved to NASA that reused launch vehicles were safe, and reused Dragon 1 capsules were safe. SpaceX seems to have given up on the idea of it anyway. They deleted landing legs from the capsule, and propulsive landing at sea as an emergency backup for the failure of all four parachutes (and you'd need to include a way to detect the failure, cut the chutes and then use the superdraco thrusters) seems a shitload of work which is probably going to only increase risk. For propulsive landing of humans/cargo, it seems Spaceship their focus.
- paranoidrobot 6y ago
  Further reply, this question was just asked and answered on the new live-stream. Official response from SpaceX: Superdraco thrusters are completely inhibited once the launch is sucessful. So, no, not even as a backup. Also, one other thing I remembered - the draco and superdraco thrusters require different pressurisation levels for their fuel systems. Before launch, the system is put into a high pressure mode, to enable launch escape. After they make orbit, the system is depressurised back to enable the draco thrusters to operate. So they'd need to have time to re-pressurise the system, too.
  - anticensor 6y ago
    Repressurisation hardware has to exist anyway to have restartability (it takes 15 minutes to switch to high pressure feed, 15 seconds to low pressure feed). Do you know which component has inhibition affected? SW only? Blown fuse? Something different? Certainly not a jettisoned part, because this vehicle is planned to be reused after minor refurbishment. PS re repressurisation failures: If it becomes absolutely necessary, a procedure could well be devised to operate the larger thrusters at a lower flow rate, albeit with a diminished efficiency and thrust.
    - paranoidrobot 6y ago
      > Do you know which component has inhibition affected? SW only? Blown fuse? Something different? Certainly not a jettisoned part, because this vehicle is planned to be reused after minor refurbishment. They didn't elaborate, it was a 30 second response.
- ufmace 6y ago
  We're not talking about the kind of system where you just turn on the rockets and it'll probably work okay here. Propulsive landing based on running 8 rockets is gonna take a ton of highly tested hardware and software, including speed and orientation sensors etc and all the software to balance things out perfectly. No way they're adding in a big pile of extra untested software and hardware for an unlikely event. NASA would never approve, and correctly so, as that would be a massive number of extra things to potentially go wrong.

sebazzz 6y ago

Not even for emergencies? Does that mean that it is officially not there, but in the unlikely unlikely event it can be used, or that it really isn't there anymore and the capsule would just drop dead on the ground?

anticensor 6y ago
It is there, just not certified for this use. However, if they manage to make a successful ememgency propulsive landing (even an unaccounted one), it will be investigated and then approved post-facto. The engines used for landing are the same engines that are used for post-second-stage maneuvreing.
Kliment 6y ago
It means it's never been tested and there's no safe way to use it - the hardware and software are not configured to have that ability for this particular flight, is how I understand it.
paranoidrobot 6y ago
> Not even for emergencies? Clearly not. NASA was already not keen about the superdraco system. The explosion that destroyed the Dragon 2 capsule that was slated for the In-flight Abort test killed any chance of it being used for human-rated flights. > Does that mean that it is officially not there This is life-critical hardware/software. You don't go putting functionality in there that isn't approved by NASA, and most importantly the crew who're going to fly it. Finding out that there's undocumented features and easter-eggs, even if they might in some very remote scenario help save life is certain to be outweighed by the risk that having it in there might somehow contribute to someone's death. Could it be used for propulsive landing? Perhaps, but they'll first have to prove to NASA that it's safe - just like they proved to NASA that reused launch vehicles were safe, and reused Dragon 1 capsules were safe. SpaceX seems to have given up on the idea of it anyway. They deleted landing legs from the capsule, and propulsive landing at sea as an emergency backup for the failure of all four parachutes (and you'd need to include a way to detect the failure, cut the chutes and then use the superdraco thrusters) seems a shitload of work which is probably going to only increase risk. For propulsive landing of humans/cargo, it seems Spaceship their focus.
paranoidrobot 6y ago
Further reply, this question was just asked and answered on the new live-stream. Official response from SpaceX: Superdraco thrusters are completely inhibited once the launch is sucessful. So, no, not even as a backup. Also, one other thing I remembered - the draco and superdraco thrusters require different pressurisation levels for their fuel systems. Before launch, the system is put into a high pressure mode, to enable launch escape. After they make orbit, the system is depressurised back to enable the draco thrusters to operate. So they'd need to have time to re-pressurise the system, too.
- anticensor 6y ago
  Repressurisation hardware has to exist anyway to have restartability (it takes 15 minutes to switch to high pressure feed, 15 seconds to low pressure feed). Do you know which component has inhibition affected? SW only? Blown fuse? Something different? Certainly not a jettisoned part, because this vehicle is planned to be reused after minor refurbishment. PS re repressurisation failures: If it becomes absolutely necessary, a procedure could well be devised to operate the larger thrusters at a lower flow rate, albeit with a diminished efficiency and thrust.
  - paranoidrobot 6y ago
    > Do you know which component has inhibition affected? SW only? Blown fuse? Something different? Certainly not a jettisoned part, because this vehicle is planned to be reused after minor refurbishment. They didn't elaborate, it was a 30 second response.
ufmace 6y ago
We're not talking about the kind of system where you just turn on the rockets and it'll probably work okay here. Propulsive landing based on running 8 rockets is gonna take a ton of highly tested hardware and software, including speed and orientation sensors etc and all the software to balance things out perfectly. No way they're adding in a big pile of extra untested software and hardware for an unlikely event. NASA would never approve, and correctly so, as that would be a massive number of extra things to potentially go wrong.