Pretty good segment on the JWST this morning on CBS Sunday Morning here in the US. (Might be region-limited - sorry, non-USA’ians).https://www.cbsnews.com/video/the-revolutionary-james-webb-space-telescope/One soundbite dropped was that the mechanism has over 300 single-point failures. That’s encouraging.

Quote from: Herb Schaltegger on 12/12/2021 01:58 pmPretty good segment on the JWST this morning on CBS Sunday Morning here in the US. (Might be region-limited - sorry, non-USA’ians).https://www.cbsnews.com/video/the-revolutionary-james-webb-space-telescope/One soundbite dropped was that the mechanism has over 300 single-point failures. That’s encouraging. Good example for a statistics prof. How reliable do each of the 300 steps need to be to have 50/50 shot at everything going to plan?

about 99.8%.Which is high, but not impossibly so. …of course 50/50 is hardly great odds! To get 95% chance of success, you need each to have 99.983% success rate… a lot harder.

Quote from: matthewkantar on 12/12/2021 07:12 pmGood example for a statistics prof. How reliable do each of the 300 steps need to be to have 50/50 shot at everything going to plan?about 99.8%.Which is high, but not impossibly so. …of course 50/50 is hardly great odds! To get 95% chance of success, you need each to have 99.983% success rate… a lot harder.

Good example for a statistics prof. How reliable do each of the 300 steps need to be to have 50/50 shot at everything going to plan?

Quote from: Robotbeat on 12/12/2021 07:45 pmQuote from: matthewkantar on 12/12/2021 07:12 pmGood example for a statistics prof. How reliable do each of the 300 steps need to be to have 50/50 shot at everything going to plan?about 99.8%.Which is high, but not impossibly so. …of course 50/50 is hardly great odds! To get 95% chance of success, you need each to have 99.983% success rate… a lot harder.99.8% is not high. For items used once per day it's a failure every year and a half. Many common devices are better than that. Door locks and car starter motors for two. Most are better than 99.99%. Six sigma is 99.9997% and there's a lot of that about.Reliability is not rocket science.

Quote from: Barley on 12/16/2021 04:14 amQuote from: Robotbeat on 12/12/2021 07:45 pmQuote from: matthewkantar on 12/12/2021 07:12 pmGood example for a statistics prof. How reliable do each of the 300 steps need to be to have 50/50 shot at everything going to plan?about 99.8%.Which is high, but not impossibly so. …of course 50/50 is hardly great odds! To get 95% chance of success, you need each to have 99.983% success rate… a lot harder.99.8% is not high. For items used once per day it's a failure every year and a half. Many common devices are better than that. Door locks and car starter motors for two. Most are better than 99.99%. Six sigma is 99.9997% and there's a lot of that about.Reliability is not rocket science.AIUI, those single point of failure points are on deployment mechanisms. Only used once.

170411Z DEC 21HYDROLANT 3083/21(24).WESTERN NORTH ATLANTIC. DNC 01. 1. HAZARDOUS OPERATIONS, ROCKET LAUNCHING 1120Z TO 1416Z DAILY 22 DEC THRU 21 JAN 22 IN AREAS BOUND BY: A. 05-27N 048-06W, 05-26N 047-11W, 04-54N 047-11W, 04-55N 048-06W. B. 05-09N 046-30W, 05-04N 044-46W, 04-46N 044-47W, 04-52N 046-31W.2. CANCEL THIS MSG 211516Z JAN 22.

170427Z DEC 21NAVAREA IV 1129/21(24).WESTERN NORTH ATLANTIC. FRENCH GUIANA. 1. HAZARDOUS OPERATIONS, ROCKET LAUNCHING 1210Z TO 1416Z DAILY 22 DEC THRU 21 JAN 22 IN AREA BOUND BY 05-18.00N 052-47.40W, 05-22.35N 052-33.83W, 05-11.16N 052-24.63W, 05-09.00N 052-36.00W.2. CANCEL THIS MSG 211516Z JAN 22.

170417Z DEC 21HYDROLANT 3084/21(57).EASTERN NORTH ATLANTIC. EASTERN SOUTH ATLANTIC. DNC 01. 1. HAZARDOUS OPERATIONS, SPACE DEBRIS 1219Z TO 1501Z DAILY 22 DEC THRU 21 JAN 22 IN AREA BOUND BY 02-03N 014-35W, 00-07S 001-57E, 01-54S 001-43E, 00-16N 014-49W. 2. CANCEL THIS MSG 211601Z JAN 22.