When I lived on the Space Coast I overheard gossip that one or more cosmonauts died in space.

Is there any truth to this?

I’m not asking about deaths from those disasters like Challenger, Columbia, or Apollo 1. I'm asking about death out in actual space.

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    It is not clear what area you asking. Death from natural causes like for example heart attack ? As far as I know, no such deaths are being recorded, because cosmonauts/astronauts are thoroughly screened for their health.
    – rs.29
    Feb 20, 2019 at 7:18
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    It's pretty clear what he's asking. At least to me. Feb 20, 2019 at 7:40
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    @edc65 The boundary of space, called the Karman line, is generally drawn at 100 km, although the USAF draws it at 50 mi (80 km). Columbia was destroyed on re-entry at about 60 km altitude, while Challenger was destroyed on ascent at 15 km and even the forward momentum of the cabin did not carry it higher than 20 km. Neither were in space by either definition. Feb 20, 2019 at 22:52
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    @rs.29 I don't see why you think there would be a distinction. Has there been ANY death (natural or otherwise) beyond the border of space? Can't get any clearer than that.
    – user32121
    Feb 21, 2019 at 4:29
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    @rs.29 it said space, which is a defined thing that doesn't need to be repeated. Actual space is anything above 100km from sea level. We live in an atmosphere, as opposed to space. This doesn't need to be repeated in the question since it is known and clear. It only mentioned disasters in the clear context of the Challenger, Columbia and Apollo 1 disasters. What is unclear?
    – user32121
    Feb 21, 2019 at 7:36

2 Answers 2


Yes, the three crew members of Soyuz 11: Georgy Dobrovolsky, Vladislav Volkov, and Viktor Patsayev.

On 29 June 1971, their spacecraft undocked from Salyut 1, the first space station, to return to Earth. In the process, however, a breathing ventilation valve between the Soyuz's orbital and descent modules was accidentally loosened. This caused a fatal decompression at ~168km above earth's surface, quickly killing the crew.

According to a NASA writeup of the incident, the cabin pressure fell to zero for nearly 12 minutes, before increasing due to the ship re-entering the Earth's atmosphere. All three cosmonauts would have passed away within the first few minutes.

They remain the only humans known to have died in outer space (conventionally defined to begin at 100km above sea level).

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    Comments are not for extended discussion; this conversation has been moved to chat.
    – T.E.D.
    Feb 22, 2019 at 21:33

The only astronauts who have ever died in space are the crew of Soyuz 11: Georgy Dobrovolsky, Vladislav Volkov, and Viktor Patsayev. This took place in 1971. Perhaps that you are thinking about the legend of the lost cosmonauts.

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    Hmmm. I'll admit I had heard a variant of that legend myself (and bought it. Silly me)
    – T.E.D.
    Feb 20, 2019 at 14:39

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