Voskhod (spacecraft) - Design

Design

The Voskhod spacecraft was basically a Vostok spacecraft that had a backup, solid fuel retro rocket, added to the top of the descent module. The ejection seat was removed and two or three crew couches were added to the interior at a 90-degree angle to that of the Vostok crew position. In the case of Voskhod 2, an inflatable exterior airlock was also added to the descent module opposite the entry hatch. After use, the airlock was jettisoned. There was no provision for crew escape in the event of a launch or landing emergency. A solid fuel braking rocket was also added to the parachute lines to provide for a softer landing at touchdown. This was necessary because, unlike the Vostok, the crew landed with the Voskhod descent module.

In order to create more space inside the descent module, the cosmonaut's ejection seat was removed, meaning that the Voskhod crews would return to Earth inside their spacecraft, unlike the Vostok cosmonauts who ejected and parachuted down separately. The lack of space also meant that the Voskhod 1 crew did not wear space suits. Both crew members wore spacesuits on the Voskhod 2 mission, as it involved an EVA and used an airlock. The second crew member wore a spacesuit as a precaution against the possibility of accidental descent module depressurization. Because the crew was required to land with the descent module, a new landing system to slow the craft was developed. This added a small solid-fuel rocket to the parachute lines. It fired as the descent module neared touchdown, providing a softer landing than did Vostok. A backup solid-fuel retrorocket was added to the top of the descent module. The original Vostok spacecraft only had one liquid fuel retrorocket and no provision for backup. The Vostok did carry enough onboard supplies for a 10-day flight. This would allow for natural orbit decay and reentry if the retrorocket failed. Finally, the Voskhod 2 spacecraft carried a large inflatable airlock that allowed cosmonaut Aleksei Leonov to exit and re-enter the craft. This was needed because the vehicle's electrical and environmental systems were air-cooled, and complete capsule depressurization would lead to overheating.

The airlock carried on Voskhod 2 weighed 250 kg, was 700 mm in diameter, 770 mm high when collapsed for launch. When extended in orbit, the airlock was 2.5 m long. It had an internal diameter of 1.0 m and an external diameter of 1.2 m.

This spacecraft was carried into orbit by the Voskhod rocket, also developed from the earlier Vostok rocket and ultimately derived from the R-7 ICBM.