3 ms·

It’s underpromising and over delivering. They knew internally that it could fly 16x more. They just didn’t want to say it in a statement publicly.

rvnx 3y ago
It also means costs and estimates are incorrect and a potential waste of public resources
- acdha 3y ago
  Again, nothing is incorrect here: a margin is only waste if you’re a Walmart MBA obsessed with lowering costs. If the DOT builds a bridge with a 70 ton rating and it doesn’t collapse when an 80 ton truck drives over it, that’s not waste but rather the engineers prudently including a safety margin in each component to protect against minor defects or inconsistencies meaning that one component being slightly under spec causes the entire system to fail. NASA and aerospace as a field traditionally have a bias towards that kind of overlapping safety margins because the kinds of failures they get destroy the entire air/space-craft. If some MBA at GE cost-optimizes your dishwasher, they’re better off trimming “waste” until it dies the day after the warranty expires as long as it doesn’t fail in a way which causes you never to buy their brand again. NASA faces far more catastrophic failures and because their systems are all custom with economy of scale for large product runs and their missions by necessity have a hefty base cost so it doesn’t make sense to save $50k on rover parts when you are paying $500M to ship it to Mars.
coryrc 3y ago
They knew it would last exactly 80 flights? Wow, they are good.
glenstein 3y ago
Actively promising outcomes that push equipment to the brink of failure would be malpractice and the planners would deservedly be fired. These are novel and truly unprecedented space missions. There may yet be a future in which we can confidently predict outcomes at scale, but we are not there yet. Being conservative in assumptions is a virtue, and hopefully is emulated in every future mission.

rvnx 3y ago

It also means costs and estimates are incorrect and a potential waste of public resources

acdha 3y ago
Again, nothing is incorrect here: a margin is only waste if you’re a Walmart MBA obsessed with lowering costs. If the DOT builds a bridge with a 70 ton rating and it doesn’t collapse when an 80 ton truck drives over it, that’s not waste but rather the engineers prudently including a safety margin in each component to protect against minor defects or inconsistencies meaning that one component being slightly under spec causes the entire system to fail. NASA and aerospace as a field traditionally have a bias towards that kind of overlapping safety margins because the kinds of failures they get destroy the entire air/space-craft. If some MBA at GE cost-optimizes your dishwasher, they’re better off trimming “waste” until it dies the day after the warranty expires as long as it doesn’t fail in a way which causes you never to buy their brand again. NASA faces far more catastrophic failures and because their systems are all custom with economy of scale for large product runs and their missions by necessity have a hefty base cost so it doesn’t make sense to save $50k on rover parts when you are paying $500M to ship it to Mars.

coryrc 3y ago

They knew it would last exactly 80 flights? Wow, they are good.

glenstein 3y ago

Actively promising outcomes that push equipment to the brink of failure would be malpractice and the planners would deservedly be fired. These are novel and truly unprecedented space missions. There may yet be a future in which we can confidently predict outcomes at scale, but we are not there yet. Being conservative in assumptions is a virtue, and hopefully is emulated in every future mission.