Comments by "SeanBZA" (@SeanBZA) on "Thunderf00t" channel.

  1. 45
  2. 42
  3. Thing is that they literally have the glue bond inside out, as the ring should have had an internal structure as well, to transfer the compression force from the carbon fibre to the inner titanium ring via the epoxy, not put a tensile pull on the epoxy join. That would lead to the carbon fibre delaminating with pressure cycles, and failing. They constructed that join surface as if the join was for a pipe with pressure inside, where the pressure will hold the epoxy onto the cap, not the other way round. Pipe shrank under pressure, and eventually some microscopic section of the join, likely with an embedded air bubble in it that had been compressed to have a sharp edge, caused a stress that started to propagate through the bulk resin, because there is no stress relief in the resin bond, and this then eventually grew to the outside, where water was able to fill the crack. Now the water is applying pressure to a section that can flex, and grows the crack into the joint further, aided by the tension in the epoxy join, and this then rapidly, basically the speed of sound in the epoxy as the growth speed, grew to open the joint to the inside. That joint should have had an inner and outer lip, and have been filled with epoxy with a slow cure time, and then have the shell pressed down into it, also with a coat of the epoxy on the surfaces, and then pressed together, with a few vent holes for the excess resin to flow out in the titanium, that later on would have a cap bolted and bonded to it. Or a thicker section that you put a setscrew in to fill the hole, while the resin is still not cured, after it has bottomed out, then left and heated to cure fully before removing the pressure. That join section should have been at least 3 times thicker, and longer, with a taper on the inside to allow a flexible sealer to be there, to allow the join to flex with pressure, not a solid non flex epoxy only. you want to not have stress risers, and a solid join with the different materials will have that stress riser. This hull was likely only going to last 3 cycles before you would have to replace it, they should have done testing, using a deep water area, and a cable and cage, to measure the number of cycles to failure first, not used the passengers as alpha testers.
    23
  4. 18
  5. 15
  6. 11
  7. 10
  8. 9
  9. 7
  10. 7
  11. 7
  12. 7
  13. 6
  14. 6
  15. 6
  16. 5
  17. 5
  18. 4
  19.  @eno2870  That would be extra, as you then have to use medical grade oxygen, which has a much lower concentration of contaminants, most notable being nitrogen, which is pretty close in boiling point, so you have to do fractional distillation of the liquid, or use molecular filters to reduce the volume of contaminants. Expensive and slow, as you do need to keep a very precise control on the pressures and temperatures. For each passenger you would need around 3l of liquid oxygen, per flight, and probably around 15l of liquid nitrogen as well, so as to be able to make a one atmosphere environment, and simply dump all the exhaust out of the craft. Otherwise you need lithium hydroxide CO2 scrubbers to be able to recirculate the air, and then your gas needs are lower, but you do need a lot more mass in scrubbers. However the scrubbers need to be fed dry air, so you then need to extract almost all of the humidity out of the air first. So, probably a ton of scrubbers alone, another 2 tons of airconditioners, for the hundred passengers, to save the 1500kg of liquid nitrogen, but the LOX is not going to be much less. That assumes you want to have the passengers feel like they are in an aircraft, though you could get away with dropping cabin pressure to a bit lower, and increasing oxygen concentration, but having them need to spend an hour before and after each flight doing a decompression would probably not be a desired thing. After all, the space shuttle and ISS takes the best part of a day to get ready for EVA, because the low pressure in the space suits requires all nitrogen to be removed, and the time for the Starship will not be much less.
    4
  20. 4
  21. 4
  22. 3
  23. 3
  24. 3
  25. 3
  26. 3
  27. 3
  28. 3
  29. 3
  30. 2
  31. 2
  32. 2
  33. 2
  34. 1
  35. 1
  36. 1
  37. 1
  38. 1
  39. 1
  40. 1
  41. 1
  42. 1
  43. 1
  44. 1
  45. 1
  46. 1
  47. 1
  48. 1
  49. 1
  50. 1
  51. 1
  52. 1
  53. 1
  54. 1
  55. 1
  56. 1
  57. 1
  58. 1
  59. 1
  60. 1
  61. 1
  62. 1
  63. 1
  64. 1