SK-1 is an initialism of "Skafandr Kosmicheskiy" # 1 (Скафандр Космический = "diving suit for space") is a spacesuit that was developed specially for Yuri Gagarin. As such, it is the first spacesuit ever used. After his successful flight on the Vostok 1 spacecraft, spacesuits of the SK series were used for space flights of other cosmonauts on Vostok spacecraft, in which the cosmonauts would eject and land separately from module.

The SK-1 was used from 1961-1963.^{[not verified in body]}

SK-2 (CK-2)

Almost exactly the same as the SK-1 but designed for a woman, it was on June 16 through 19th in 1963 on Vostok 6.^{[citation needed]}

Specifications

Allowed ejections up to 8 km (26,000 ft).^[1]

• Name: SK-1/SK-2 Spacesuit^[1]
• Manufacturer: NPP Zvezda
• Missions: Vostok 1 to Vostok 6
• Function: Intra-vehicular activity (IVA) and Ejection^[1]
• Operating Pressure: 270 to 300 hPa (3.9 to 4.4 psi)^[1]
• Suit Weight: 20 kg (44 lb)^[1]
• Primary Life Support: Vehicle Provided