3 ms·

Someone opened an issue: "Check continuity on O2 cryogenic tanks before allowing stir" https://github.com/chrislgarry/Apollo-11/issues/3 https://github.com/chr

• kol 10y ago
  LOL
• dingo_bat 10y ago
  And it's been marked wontfix.
• Isn0gud 10y ago
  ELI5?
  • js2 10y ago
    https://news.ycombinator.com/item?id=12055780 https://news.ycombinator.com/item?id=12055780
• js2 10y ago
  This is a classic XY issue, suggesting a fix ("Check continuity...") instead of describing the problem ("O2 tanks exploded during Apollo 13 mission"). Further, I believe that the suggested fix is incorrect, or at least insufficient. The Apollo 13 investigation indicated that a list of factors led to the fan wires in the O2 tanks having damaged insulation. However, unless the wires were already short-circuited before stirring, checking continuity first would not have detected the short. Indeed, the tank was stirred twice earlier in the mission without incident. The investigation suggested that operating the fans itself may have eventually moved the wires into contact with each other, which combined with the damaged insulation, finally allowed an electrical arc and the resulting explosion to occur. The correct fix is to upgrade the thermostatic switches which protect the tank heaters from overheating to accommodate 65 V DC, so that the fan wiring isn't damaged in the first place. In addition, the tank acceptance procedure should be amended to require switch cycling under load. Source: http://history.nasa.gov/SP-4029/Apollo_13a_Summary.htm http://history.nasa.gov/SP-4029/Apollo_13a_Summary.htm
  • jakub_h 10y ago
    Or maybe describing the problem in the explicit way you mentioned instead of the oblique way would have ruined the joke?