Vika oxygen generator

Vika or TGK is an oxygen generating system for spaceflight.^[1] It is a SFOG, or solid-fuel oxygen generator, a kind of chemical oxygen generator.^[1] It has been used on the retired Mir space station and the International Space Station.^[1] It was originally developed by Roscosmos to supplement the Elektron oxygen system on Mir.^[1] A Vika module, also known as a "candle", contains about one liter of lithium perchlorate and can provide oxygen for one person for 24 hours.^[1]

After being adopted for use on the ISS, it had the NASA name SFOG, but they also sometimes use the Russian acronym TGK.^[1]

Vika on Mir

Astronaut Jerry Linenger wearing a respirator mask following the 1997 fire aboard Mir from an SFOG fire

Vika was used on Mir when more than three people were on board.^[2] Vika needs a supply of canisters to work, which must be flown into space.^[2] An example of this is Progress M-34, which carried 60 canisters to Mir in 1997 along with other cargo.^[2] If Vika and Elektron stopped working, the station would have to rely on a limited supply of bottled oxygen.^[2]

The fire was a "raging blowtorch" ..

—Mir crewmember onboard during the fire^[1]

In February 1997 a Vika chemical oxygen generator failed on Mir in the Kvant-1 module. It caught fire and spewed a torch-like jet of a molten metal and sparks across one of the Mir space station modules, burning for around 14 minutes and blocking the escape route to the docked Soyuz spacecraft.^[1] The fire was eventually extinguished, and the crew was not harmed.^[1] A definitive cause of the accident was not determined because the fire destroyed the device. It was suspected that a torn piece of rubber glove worn during assembly likely contaminated the canister.^[1] Despite this incident, NASA decided it was still the best supplemental oxygen system available, and supported its use on the then-upcoming ISS.^[1] The US and Russia worked together to improve the safety of the system before using it on the new space station.^[1]

Vika on ISS

See also: ISS ECLSS

A backup to the temperamental^{[citation needed]} Elektron system used on both the ISS and Mir is the Vika solid-fuel oxygen generator (SFOG), which contains a replaceable cartridge – a thin-walled steel tube with a three-part block of oxygen-releasing mixture based on lithium perchlorate. Two parts are tablets of the chemical mixture and the third one is the igniter tablet with a flash igniter. The igniter is struck by a firing pin when the device is activated. One cartridge releases 600 litres (160 US gal) of oxygen and burns for 5–20 minutes at 450–500 °C (842–932 °F).^[3] The oxygen is cooled and filtered to remove dust and odours, and released into the space station atmosphere.^{[citation needed]}

See also

• Life-support system