4 ms·
> 80% sounds bad but the chance of two launches failing is 4%, which means a 96% chance overall success rate I'm sorry, but this argument is also mathematicall
by nightcracker 7y ago
> 80% sounds bad but the chance of two launches failing is 4%, which means a 96% chance overall success rate
I'm sorry, but this argument is also mathematically illiterate. Probability only works this way if the events are uncorrelated, but it should be pretty clear they're not.
If the first rocket has a 20% chance to fail it is likely that the second one will also fail due to similar negligence.
- eru 7y agoIt goes both ways. Perhaps they make the same mistakes, perhaps they'd learn from their mistakes, and would _not_ make the same ones?
- akiselev 7y agoYou're right in theory but demonstrably wrong in reality. Just look at the failure rate of launch platforms in the last 30 years. If I remember correctly, launch failures accounted for less than half of mission failures and a significant number of those weren't explosions but burn rate problems that ended up in the wrong orbit. Rockets aren't mass manufactured and their fabrication is barely automated. Nobody except SpaceX keeps their tooling online long enough to have correlating failures except for actual design issues which are fixed in later launches. The correlated failure comes from the actual mission hardware but launch schedules are so spread out that a second mission has plenty of time to fix issues discovered in the first attempt. If rockets, which are made one at a time and launch maybe a few times a year, had correlating failures like you said, no insurance company would cover launches.