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How is the problem and solution different than the parachutes used in early NASA programs like Mercury? > Since the design of Boeing’s parachute system is so s

How is the problem and solution different than the parachutes used in early NASA programs like Mercury? > Since the design of Boeing’s parachute system is so similar to NASA’s, the company had to perform fewer tests to demonstrate the system’s safety compared to SpaceX. This doesn't seem like a good habit for Boeing.

GhettoMaestro 7y ago
> This doesn't seem like a good habit for Boeing. While I like to bang on Boeing for being fucking dumb about 737MAX, the habit of copying an existing well-tested, approved design is something that should NOT be discouraged. Re-use of existing validated solutions / components leads to faster development cycles and increased agility (financially) . This is achieved by making more critical components COTS (Commercial Off The Shelf - not one-off / custom) and re-usable as self-contained "modules" or "packages". Reinventing the wheel for reinventing the wheel's sake is in most cases not a good use of resources. That said, if the original design has issues, my above commentary is invalidated somewhat - you need to modify the design to fix the root cause, which should trigger a fresh round of validation and testing at the original specification levels or greater. And of course, you should always do fully integrated tests, even if all of the components were previously validated and approved. You pretty much always find stuff (maybe only in solution-integrated combination) - I believe that's what happened in this case.
- pizzaparty2 7y ago
  Using old tech is why Boeing lost space though.
  - GhettoMaestro 7y ago
    "Lost" space? I'm not following you. Unless you're referring to how up-start SpaceX has dominated the launch industry in the past 5 to 10 years?
- bendbro 7y ago
  I don't think he means existing designs shouldn't be reused. I think he means that you shouldn't lessen testing because you are using an existing designs. Boeing reused the 737 design to produce the 737 Max; however, because it was a reused design, Boeing did not go through the same certification process or testing that would have been done for a new airplane. Skipping testing because you have a reused design is the bad habit he is referring to.
caconym_ 7y ago
From a quick Googling, the heaviest Mercury capsule launched weighed 3k lbs, while Crew Dragon is 20k lbs dry. That extra mass makes the problem significantly more complicated. As for later programs like Apollo that are more comparable, I'm not sure. Maybe they were comfortable with heavier systems or worse safety margins. Also, I expect that working out the parachutes for Apollo was not easy.
- gpm 7y ago
  Apollo also had parachute issues, e.g. see Apollo 15.
WalterBright 7y ago
> This doesn't seem like a good habit for Boeing. Using pre-existing proven designs for components is essential for building safe systems.

GhettoMaestro 7y ago

> This doesn't seem like a good habit for Boeing. While I like to bang on Boeing for being fucking dumb about 737MAX, the habit of copying an existing well-tested, approved design is something that should NOT be discouraged. Re-use of existing validated solutions / components leads to faster development cycles and increased agility (financially) . This is achieved by making more critical components COTS (Commercial Off The Shelf - not one-off / custom) and re-usable as self-contained "modules" or "packages". Reinventing the wheel for reinventing the wheel's sake is in most cases not a good use of resources. That said, if the original design has issues, my above commentary is invalidated somewhat - you need to modify the design to fix the root cause, which should trigger a fresh round of validation and testing at the original specification levels or greater. And of course, you should always do fully integrated tests, even if all of the components were previously validated and approved. You pretty much always find stuff (maybe only in solution-integrated combination) - I believe that's what happened in this case.

pizzaparty2 7y ago
Using old tech is why Boeing lost space though.
- GhettoMaestro 7y ago
  "Lost" space? I'm not following you. Unless you're referring to how up-start SpaceX has dominated the launch industry in the past 5 to 10 years?
bendbro 7y ago
I don't think he means existing designs shouldn't be reused. I think he means that you shouldn't lessen testing because you are using an existing designs. Boeing reused the 737 design to produce the 737 Max; however, because it was a reused design, Boeing did not go through the same certification process or testing that would have been done for a new airplane. Skipping testing because you have a reused design is the bad habit he is referring to.

caconym_ 7y ago

From a quick Googling, the heaviest Mercury capsule launched weighed 3k lbs, while Crew Dragon is 20k lbs dry. That extra mass makes the problem significantly more complicated. As for later programs like Apollo that are more comparable, I'm not sure. Maybe they were comfortable with heavier systems or worse safety margins. Also, I expect that working out the parachutes for Apollo was not easy.

gpm 7y ago
Apollo also had parachute issues, e.g. see Apollo 15.

WalterBright 7y ago

> This doesn't seem like a good habit for Boeing. Using pre-existing proven designs for components is essential for building safe systems.