Hacker News Reader

Comment by gus_massa | Hacker News Reader

The failure rate in manned space missions is approximately 1/50 ("failure" as in "it explodes and everybody dies"). (For example, the Space Shuttle had 2/135 failures.)

The unmanned missions have a higher failure rate, IIRC ~10%, but that number probably includes prototype and old models.

So a 2/80 failures is not so bad. It sucks when it explodes, but going to space is difficult.

View on HN

That 1/50 failure rate is debatable, and depends on your definition.

For example, Soviet/Russian manned flight, "Soyuz", had 131 flights (123 Soyuz + 2 Voskhod + 6 Vostok) [1][2] and 2 accidents, resulted in death of 4 astronauts (1 + 3).[3]

However, both of these accidents occurred before 1972, and both were highly experimental flights. Komarov's was the VERY FIRST flight of Soyuz, and before Soyuz 11 accident, they were descending without space suits, as the space inside the cabin was so tiny.

So you can also say that there were 2 accidents in the first 10 Soyuz flights - they were still finalizing the technology - and no accidents in the remaining 113.

In addition, both of these accidents occurred during the landing, so there was NO accidents during manned-space take-off in Russian/Soviet flights.

[1] http://en.wikipedia.org/wiki/List_of_Russian_manned_space_mi... [2] http://en.wikipedia.org/wiki/List_of_Soviet_manned_space_mis...

[3] http://en.wikipedia.org/wiki/List_of_spaceflight-related_acc...

> "there was NO accidents during manned-space take-off in Russian/Soviet flights."

Soyuz T-10-1 burned on the launch pad, although the launch escape system saved the lives of the cosmonauts on board.

http://en.wikipedia.org/wiki/Soyuz_7K-ST_No._16L

Thanks - I stand corrected, I didn't know about that accident.

Still, it wouldn't be a "failure" under GP's original definition: "failure" as in "it explodes and everybody dies" :)

It should also be noted that Komarov died in first manned Soyuz spacecraft launched - not the first Soyuz. In other words, Komarov's Soyuz-1 - and naming system isn't obvious in Russian space school - wasn't analogous to Columbia first flight as the very first flight of any STS.

And in Soyuz they also had other pretty close calls. Diving into athmosphere hatch-forward because engine module didn't separate in Shatalov-Volynov-Eliseev-Khrunov group flight... Near premature separation of said engine module in the Intercosmos flight with Afghani cosmonaut... Several ballistic landings - with accelerations up to about 20 g's...

Still nobody died. Perhaps in no small part because of overbuilding the ship and also changing the ship design along its long history, learning on mistakes. Soyuz spacecraft is the real workhorse.

There was another unsuccessful launch, when second stage rocket hasn't properly separated from the third. Everyone survived, but they have experienced pretty high acceleration and landed just 21 minutes after the launch.

http://en.wikipedia.org/wiki/Soyuz_7K-T_No.39

Also here is a nice video that shows: "How Soyuz Works".

https://www.youtube.com/watch?v=AVvgpKt5uCA

Basically how cosomaunts train in Star City to how the rocket is built, take off and all the way till it is about to dock with the ISS, including how launch escape works etc.

The reliability and resilience of the system is just a marvel of engineering.

Reply on news.ycombinator.com