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Sokol KV-2
Designation: Sokol-KV2
The longest-continuously-flying crewed spacesuit in history — 45+ years of active Soyuz service since 1980.
About This Suit
The Sokol KV-2 ('Falcon KV-2') is a soft intravehicular pressure suit worn by all Soyuz cosmonauts during launch, ascent, orbit, and reentry. It was introduced in 1980 as an improved version of the Sokol-K and remains in active service today — making it the longest-flying operational spacesuit design in history. The suit does not provide autonomous life support; it connects via umbilical to Soyuz's spacecraft systems and inflates only in an emergency cabin depressurization. Its development was prompted by the Soyuz 11 disaster in 1971, when three cosmonauts died of asphyxiation during a cabin leak on reentry because no suits were worn. The Sokol design philosophy — lightweight, simple, worn throughout the entire flight — became the standard for all subsequent crew capsule suits and was licensed to China for the Shenzhou program.
Key Features
- 1Direct design response to the 1971 Soyuz 11 disaster (3 deaths from unsuited depressurization)
- 2Lightweight soft construction — weighs only 10 kg, worn for entire Soyuz flight profile
- 3Connects via chest umbilical to spacecraft for O₂, pressure, and data — not self-contained
- 4Rubberized polycaprolactam pressure bladder (improved over Sokol-K's neoprene)
- 5Modular sizing system accommodating different anthropometric builds
- 6Technology-transferred to China as basis for Shenzhou IVA suit
Historic Missions
1980
Soyuz T-2
First flight of Sokol KV-2
👨🚀 Yuri Malyshev, Vladimir Aksyonov
1980
Every crewed Soyuz flight
Used on all Soyuz missions from 1980 to present — over 150 crewed flights
2024
Soyuz MS-26 (Starliner return crew)
Butch Wilmore and Suni Williams returned in Sokol suits after 9 months stranded on ISS
Engineering & Research Highlights
- ◆Demonstrated that a single lightweight suit design could serve all phases of a crewed spaceflight for 45+ years
- ◆Technology transfer to China established Shenzhou IVA design — proving international suit architecture replication