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Comment by justin66 | Hacker News Reader

> the loss rate for rockets

I wonder how you constructed that comparison such that it seemed meaningful. I'm pretty sure the lesson when you look at the data would be "fly on a man-rated Soyuz, not a Space Shuttle."

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Loss rate for Space Shuttle program was 1.5%

135 missions, 2 lost.

Do you see that as an indictment of the safety of manned space flight, or the safety of that vehicle? (you do understand that the modern Soyuz is quite safe, right? One can expect SpaceX's stuff to be safer.)

Are you looking at failures per mission or fatalities per person-trip? I thought the shuttle and Soyuz were very close on the fatalities per person-trip metric.

I'm surprised by that. They haven't lost a Soyuz crew since 1971, and they've flown quite a few.

(Soyuz capsules have had one or two pretty hard landings that I'm aware of. That's a failure mode that the newer capsules probably won't have.)

I can't quickly find a source, but back of the envelope is there have been 134 Soyuz manned missions. The number of people varies 1-3, most often 3 but occasionally 2. There were 135 Shuttle manned missions. Number there varied between 2-7, but ballpark looks like 6 was common.

So if we say 3 x 134 on Soyuz, there are 402 person-trips and 6 x 135 on Shuttle it is 810 person-trips. There were 4 Soyuz fatalities and 14 on the shuttle. So Soyuz fatality rate is about 1/100 and the shuttle is 1/56. So maybe it is closer to a factor 2 of difference.

The fatal mission rate is nearly identical (both have 2 fatal missions each).

https://en.wikipedia.org/wiki/List_of_Russian_manned_space_m... https://en.wikipedia.org/wiki/List_of_Soviet_manned_space_mi... https://en.wikipedia.org/wiki/List_of_Space_Shuttle_missions

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