It's frequently claimed without citation that Alexey Leonov carried a poison pill of some kind during his Voskhod 2 spacewalk mission, to commit suicide should he be unable to re-enter the spacecraft. Examples: here, here.

This seems unlikely:

  • As American astronauts such as Jim Lovell have stated, simply depressurizing a suit or spacecraft would be a quicker and more comfortable method of suicide.
  • Any poison pill intended for use in a spacewalk would have to be accessible by mouth alone inside the helmet, which presents a possibility of accidental ingestion.

I'm taking Lovell at his word that the American program never included poison pills:

Since Apollo 13 many people have asked me, "Did you have suicide pills on board?" We didn't, and I never heard of such a thing in the eleven years I spent as an astronaut and NASA executive.

There is no mention of suicide pills in Asif Siddiqi's extremely thorough history of the USSR's early space program (part 1, part 2). A search of the text for key terms "poison", "cyanide", and "suicide" yield references to an automated poison injector for Laika's benefit, but nothing related to human cosmonauts.

Mary Roach, in Packing For Mars, casts doubt on it:

Space physiology expert Jon Clark told me the [Leonov] suicide pill story is most likely untrue. I had emailed Clark at his office at the National Space Biomedical Research Institute regarding the perplexing logistics of pill-popping in a spacesuit, and he did some asking around. His Russian sources also dismissed another rumour, that Belyayev was under orders to shoot Leonov if he couldn't get back in...

The 1997 document Walking To Olympus states:

Leonov recently revealed that he had a suicide pill he could have swallowed if he had been unable to ingress Voskhod 2 and Belyayev had been forced to leave him in orbit.

I followed up the citations from that article; the most likely source for this statement is “Orbital Castling: Life of Mir Station Will Be Prolonged Three More Years,” Segodnya in Russian, May 11, 1995, p. 9. Translated in JPRS Report, Central Eurasia: Space, August 2, 1995 (FBIS-UST-95-030), p. 20, but I can't find the article online.

Is there any credible evidence that any cosmonaut carried poison pills, or for that matter any other device primarily intended for suicide?

  • $\begingroup$ I've deleted the twin mis-posted answers. Sorry about the aesthetics, I still can't figure out how this happened. Good luck with the poison pills! $\endgroup$
    – uhoh
    Aug 11, 2017 at 17:37
  • $\begingroup$ Would finding a transcript of direct interview with Leonov, where he tells about the suicide pill be a sufficient source? $\endgroup$
    – SF.
    Aug 11, 2017 at 22:39
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    $\begingroup$ That would be ideal. Leonov could be lying, of course, but I'd take it as "credible evidence". I'd be curious about his exact wording, like, "I had a cyanide pill in a little holder on the right side of my helmet" versus "People ask if I had a cyanide pill; we had a method in case anything like that was necessary" would mean very different things to me. $\endgroup$ Aug 11, 2017 at 22:53
  • $\begingroup$ I tried to search for Leonov's interview in Russian where he would say something like this, but I couldn't find anything. Of course, it may just mean that my Google-fu is not good enough. $\endgroup$
    – Litho
    Nov 22, 2017 at 14:06
  • $\begingroup$ Probably a hoax. Russian segment of internet, as indexed by Google and Yandex, refers mostly to unspecified "cold war NASA records". Other sources do not refer to anything. I will redirect this question to Vitaly Yegorov, who works for Dauria Aerospace and knows some of the cosmonauts in person. $\endgroup$
    – ZuOverture
    Nov 30, 2017 at 5:31

2 Answers 2


I went on a quest to try and get the sources for all the citations for that article; I was partially successful. I have FOIA requests out for the documents I was not able to find on the internet, and thanks to a fantastic librarian at UC San Diego I got a scan of the document that I think spurred this.

  • “The First Egress of Man Into Space” (NASA TT F-9727), by Alexei Leonov, translation of “Pervyy vykhod chelovka v kosmicheskoye prostranstvo,” presented at the XIVth International Astronautics Congress, Athens, September 13-18, 1965

    • Does not contain any information relevant to the technical aspects of the mission or any information relevant to the use of suicide pills
  • “Orbital Castling: Life of Mir Station Will Be Prolonged Three More Years,” Segodnya in Russian, May 11, 1995, p. 9. Translated in JPRS Report, Central Eurasia. Space, August 2, 1995 (FBIS-UST-95-030), p. 20

    • This is a translation of an article in the Moscow SEGODNYA (Moscow Today) by Mikhail Chernyshov

      Despite the fact that the type of work done in open space this year has been carried out for three decades, each new space walk invariably brings its surprises. Aleksey Leonov during his first "five meter" walk almost got stuck in the hatch upon return to the airlock. Several methods were worked out to assist the cosmonaut. If nothing had assisted Leonov, not entering into the airlock, he would have been transformed into a "living satellite"; the last recourse would have been "self liquidation" by means of an ampul or tablet similar to those which have been supplied to professionals of SMERSH and other espionage services. The cosmonaut decided to tell about this quite recently. This delicate detail, judging from everything, belongs among the greatest medical secrets. In any case, until recently not even Flight Control specialists knew about this.

      (Relevant passage, the whole document can be found here)

  • “Man In Open Space,” Soviet Military Review interview, March, 1980, pp. 14-17. In USSR Report: Space, No. 11 (JPRS 78264), June 10, 1981, p. 19

    • Thanks to the help of another amazing Librarian I was able to get a copy of this article (you can find it here), it does not make any mention of a suicide pill during a spacewalk
  • “The Friendly Solar Wind,” Komsomol’skaya Pravda in Russian, Alexei Leonov, March 8, 1983, p. 4. Translated in USSR Report: Space, No. 24 (JPRS 84161), August 22, 1983, pp. 11-13 (source)

    • Does not contain any information relevant to the technical aspects of the mission mostly just about his experience
  • “Voskhod 2 Flight Recalled,” Spaceflight, June 1990, p. 193; Astronautics and Aeronautics, 1965, NASA SP 4006, 1966, pp. 132, 138. (source)

    • Some technical information about the orbit and the spacewalk itself

I think that this idea was most likely spurred initially by the article "Orbital Castling: Life of Mir Station Will Be Prolonged Three More Years" I am continuing to try and find the source for the statement in the article, but based on the amount of copy-pasting references that can be found by searching for that document I think that all the current texts that are out there can be traced back to that article.

I also purchased "Two Sides of the Moon: Our Story of the Cold War Space Race" a dual autobiography by Alexei Leonov and David Scott, in the book there was no mention of the suicide pill.

Due to a lack of primary sources mentioning it, and the only reference being a newspaper that alluded to another source I would say that it is implausible that it really happened.

  • $\begingroup$ Argh! Well, thank you for finding that -- I don't think the other sources are going to shed any more light. I was hoping for a more definite horse's-mouth statement. If nothing else comes to light in another day or so I'll give you the bounty. $\endgroup$ Nov 22, 2017 at 4:42
  • $\begingroup$ @RussellBorogove don't give up hope; I am traveling tomorrow to spend a couple of hours at the research library trying to find the original source $\endgroup$
    – Mark Omo
    Nov 22, 2017 at 4:45
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    $\begingroup$ @RussellBorogove No luck I did get ahold of another one of the references bit after digging around I was unable to find any other direct quotes. Alexey Leonov is still alive, so it may be possible to ask him directly, but I was unable to find any contact info for him other than the address to send things to get signed. $\endgroup$
    – Mark Omo
    Nov 22, 2017 at 19:30
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    $\begingroup$ @MarkOmo: You could send him a writing with a passage stating "I, Alexey Leonov, confirm that I had been carrying a suicide pill with me on my mission _______" And see if you get it returned signed or unsigned ^^' $\endgroup$
    – Zaibis
    Feb 27, 2019 at 7:30

According to The First Soviet Cosmonaut Team: Their Lives and Legacies, in the book The Rocket Men, Leonov is said to have revealed, that he indeed had a pill in the helmet. His space walk was a close call according to the account given. The original source is not available, at least not online.

As a side note, U2 pilots where given suicide devices, so it is not too far fetched, that astronauts carried them as well.

  • 2
    $\begingroup$ The cited source is "The Rocket Men: Vostok and Voskhod"; I searched that text with Google Books for the terms "pill", "poison", "suicide", "helmet", and finally "Leonov" finding no relevant results. (Some of the search results come from pages which are not part of the full text preview, so it's unclear to me whether or not the search covers the full text.) In any case, that book dates to 2001, so if anything it probably winds up leading back to the 1995 article. $\endgroup$ Nov 21, 2017 at 16:08
  • $\begingroup$ I can't find "The Rocket Men: Vostok and Voskhod" online... $\endgroup$
    – mike
    Nov 21, 2017 at 16:19
  • $\begingroup$ "The Rocket Men: Vostok and Voskhod" was published in 2001 and probably references an earlier text like "Walking To Olympus" $\endgroup$
    – Mark Omo
    Nov 22, 2017 at 3:52
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    $\begingroup$ I think U-2 pilots carried suicide device because they were flying spy planes, rather than having anything in common with astronauts. $\endgroup$ Nov 5, 2018 at 20:59
  • $\begingroup$ @FredLarson In the days before automatic spy satellites, astronauts were very much spies too. And the Shuttle flew classified missions through 1992. $\endgroup$
    – user71659
    Nov 6, 2018 at 22:39

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