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It's the original definition of "pushing the envelope." You start with a known flight envelope, then push a little past that. Sometimes you learn that the real

It's the original definition of "pushing the envelope." You start with a known flight envelope, then push a little past that. Sometimes you learn that the real envelope is bigger than you thought. Other times you find that the envelope is exactly where you thought it was.

timschmidt 1y ago
I notice I mis-typed and should have said you can't overstate the importance of Starlink on the development program. And I agree with you about pushing the envelope. It was really interesting to hear that they were planning on testing an engine-out scenario with this booster by lighting one of the middle 10 engines and two centers. If they can pull that off, they'll have a measurable increase in fault tolerance over Falcon 9.
__m 1y ago
is igniting the engine pushing the envelope though?
- SyzygyRhythm 1y ago
  We don't know all the things they did to the Booster, but among them were deliberately not igniting some engines as well as taking a more aggressive angle-of-attack on descent (the rocket is a fairly effective lifting body, as it turns out!). There may be more things, but between those two I think the latter was a bigger problem. It would have gotten hotter and more physically stressed. And then weakened to the point to where re-igniting the engines caused it to fail. They also used a new hot-staging maneuver, where the gases were directed out one side so that it flipped more rapidly in the other direction. It was a really fast flip! A rocket the size of a small skyscraper turning 90 degrees in just a few seconds. That could have jarred something loose, too. Hopefully we find out in the post-mortem. SpaceX doesn't typically give the public as much detail as we'd like, but they're pretty good at sharing the high-level reasons why something failed.
  - hoseja 1y ago
    >SpaceX doesn't typically give the public as much detail as we'd like It gives magnitudes more details than anyone else.
  - vardump 1y ago
    ITAR unfortunately limits what can be publicly released.

timschmidt 1y ago

I notice I mis-typed and should have said you can't overstate the importance of Starlink on the development program. And I agree with you about pushing the envelope. It was really interesting to hear that they were planning on testing an engine-out scenario with this booster by lighting one of the middle 10 engines and two centers. If they can pull that off, they'll have a measurable increase in fault tolerance over Falcon 9.

__m 1y ago

is igniting the engine pushing the envelope though?

SyzygyRhythm 1y ago
We don't know all the things they did to the Booster, but among them were deliberately not igniting some engines as well as taking a more aggressive angle-of-attack on descent (the rocket is a fairly effective lifting body, as it turns out!). There may be more things, but between those two I think the latter was a bigger problem. It would have gotten hotter and more physically stressed. And then weakened to the point to where re-igniting the engines caused it to fail. They also used a new hot-staging maneuver, where the gases were directed out one side so that it flipped more rapidly in the other direction. It was a really fast flip! A rocket the size of a small skyscraper turning 90 degrees in just a few seconds. That could have jarred something loose, too. Hopefully we find out in the post-mortem. SpaceX doesn't typically give the public as much detail as we'd like, but they're pretty good at sharing the high-level reasons why something failed.
- hoseja 1y ago
  >SpaceX doesn't typically give the public as much detail as we'd like It gives magnitudes more details than anyone else.
- vardump 1y ago
  ITAR unfortunately limits what can be publicly released.