The spacesuit used for the first spacewalk used open-loop ventilation, venting exhaust gases into space:

On reaching orbit in Voskhod 2, Leonov and Belyayev attached the EVA backpack to Leonov's Berkut ("Golden Eagle") space suit, a modified Vostok Sokol-1 intravehicular (IV) suit. The white metal EVA backpack provided 45 minutes of oxygen for breathing and cooling. Oxygen vented through a relief valve into space, carrying away heat, moisture, and exhaled carbon dioxide.


What was the first Soviet or Russian spacesuit to use closed-loop ventilation, where the exhaust gases are scrubbed and re-used?

Not to be confused with this closed-loop cooling question.


1 Answer 1


First of all, in Russia, the term 'spacesuit' (скафандр) can be a little ambiguous as it refers not only to space suits, but to generally any suit that isolates a human from the environment and provides a living environment within. Going by that characteristic, the first closed- loop suits were developed very early on in the 1930s. These models (СК–ЦАГИ and Ч) had a closed-loop ventilation system already since the goal was to allow a prolonged stay in the stratosphere. The need for developing hermetically sealed suits led to the creation of the "Zvezda" R&D facilities.

"Zvezda" focused on development of different suits and egress mechanisms. Importantly for this question, they were tasked with the development of the pod for the animal launches into space (which Laika flew in), as seen below.Space pod for animals

Technically, this is the first spacesuit with a closed-loop ventilation system, but this is stretching the definition of the word "spacesuit" a bit. So let's look at the spacesuits made for humans.

They were also made by "Zvezda". Indeed, up until "Berkut", the spacesuits were all open-loop. However, development of the closed-loop spacesuits commenced in 1966, a year after Leonov's EVA. Two spacesuits were developed: "Yastreb" (hawk) and "Krechet" (gyrfalcon), also known as "Krechet-94".

Yastreb (shown below) was intended for EVAs in orbit. It was used only once, when Khrunov and Alekseev moved from Souyz-5 to Souyz-4 though outer space in 1969.Yastreb space suit

"Krechet" (shown below) was intended to be used by the Soviet moon program. It had a much more complicated design, including food/drink systems, waste processing, radio, telemetry. It had passed all the tests in 1969, but never saw any use as the moon landing program was cancelled. Krechet space suit

The direct descendant of the "Krechet" is "Orlan" (sea eagle), which was designed for use on the space stations and is used in the ISS to this day.

To summarize: the first Soviet spacesuit that had closed-loop ventilation and saw any use was "Yastreb". "Krechet" was developed alongside it and had completed all the tests in the same year as "Yastreb" was first used in an EVA, but it never was used in space.


  • $\begingroup$ "generally any suit any suit that isolates a human from the environment" ...and provides a living environment for its occupant? A strong plastic shrink-wrap bag might isolate a human from space but wouldn't really be very satisfactory for its occupant. $\endgroup$
    – uhoh
    Jul 26, 2021 at 10:08
  • $\begingroup$ @uhoh You are right, but I personally thought this was always implied. Hermetically sealed suits without the ability to sustain life & work conditions seem like a torture device that would not be developed for a pilot/astronaut. $\endgroup$
    – Mu3
    Jul 26, 2021 at 10:21
  • $\begingroup$ I've added a few words to the sentence, feel free to edit further or roll back, but I think it's important to be explicit to avoid ambiguity. Suits do not isolate astronauts from cosmic rays nor visible light (though they can reduce it) nor gravity, and offer protection from only the smallest micrometeorites. What they absolutely DO do is provide a breathable gas mixture at a survivable pressure and temperature. They're defined by what they provide as much as they are by what they exclude. $\endgroup$
    – uhoh
    Jul 26, 2021 at 10:26

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