Vika or TGK is an oxygen generating system for spaceflight.
[Kerry Ellis - International Life Support - Ask Magazine]
/ref> It is a SFOG, or solid-fuel oxygen generator, a kind of chemical oxygen generator
A chemical oxygen generator is a device that releases oxygen via a chemical reaction. The oxygen source is usually an inorganic superoxide, chlorate, or perchlorate; ozonides are a promising group of oxygen sources. The generators are usually igni ...
.[ It has been used on the retired ]Mir
''Mir'' (russian: Мир, ; ) was a space station that operated in low Earth orbit from 1986 to 2001, operated by the Soviet Union and later by Russia. ''Mir'' was the first modular space station and was assembled in orbit from 1986 to& ...
space station and the International Space Station
The International Space Station (ISS) is the largest modular space station currently in low Earth orbit. It is a multinational collaborative project involving five participating space agencies: NASA (United States), Roscosmos (Russia), JAXA ( ...
.[ It was originally developed by ]Roscosmos
The State Space Corporation "Roscosmos" (russian: Государственная корпорация по космической деятельности «Роскосмос»), commonly known simply as Roscosmos (russian: Роскосмос) ...
to supplement the ''Elektron'' oxygen system on ''Mir''.[ A Vika module, also known as a "candle", contains about one liter of ]lithium perchlorate
Lithium perchlorate is the inorganic compound with the formula LiClO4. This white or colourless crystalline salt is noteworthy for its high solubility in many solvents. It exists both in anhydrous form and as a trihydrate.
Applications Inorgan ...
and can provide oxygen for one person for 24 hours.[
After being adopted for use on the ISS, it had the NASA name SFOG, but they also sometimes use the Russian acronym TGK.][
]
Vika on Mir
Vika was used on Mir when more than three people were on board.[ An example of this is ]Progress M-34
Progress M-34 (russian: Прогресс М-34, italic=yes) was a Russian uncrewed cargo spacecraft which was launched in 1997 to resupply the Mir space station, and which subsequently collided with Mir during a docking attempt, resulting in signi ...
, which carried 60 canisters to Mir in 1997 along with other cargo.[ If ''Vika'' and ''Elektron'' stopped working, the station would have to rely on a limited supply of bottled oxygen.][
In February 1997 a Vika chemical oxygen generator failed on Mir in the ]Kvant-1
Kvant-1 (russian: Квант-1; English: Quantum-I/1) (37KE) was the first module to be attached in 1987 to the Mir Core Module, which formed the core of the Soviet space station '' Mir''. It remained attached to ''Mir'' until the entire space sta ...
module. It caught fire and spewed a torch-like jet of a molten metal and sparks across one of the Mir
''Mir'' (russian: Мир, ; ) was a space station that operated in low Earth orbit from 1986 to 2001, operated by the Soviet Union and later by Russia. ''Mir'' was the first modular space station and was assembled in orbit from 1986 to& ...
space station
A space station is a spacecraft capable of supporting a human crew in orbit for an extended period of time, and is therefore a type of space habitat. It lacks major propulsion or landing systems. An orbital station or an orbital space station is ...
modules, burning for around 14 minutes and blocking the escape route to the docked Soyuz spacecraft
Soyuz () is a series of spacecraft which has been in service since the 1960s, having made more than 140 flights. It was designed for the Soviet space program by the Korolev Design Bureau (now Energia). The Soyuz succeeded the Voskhod spacecra ...
.[ The fire was eventually extinguished, and the crew was not harmed.][ 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.][ Despite this incident, NASA decided it was still the best supplemental oxygen system available, and supported its use on the then-upcoming ISS.][ The US and Russia worked together to improve the safety of the system before using it on the new space station.][
]
Vika on ISS
A backup to the temperamental 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
Lithium perchlorate is the inorganic compound with the formula LiClO4. This white or colourless crystalline salt is noteworthy for its high solubility in many solvents. It exists both in anhydrous form and as a trihydrate.
Applications Inorgan ...
. Two parts are tablets of the chemical mixture and the third one is the igniter tablet with a flash igniter
In pyrotechnics, a pyrotechnic initiator (also initiator or igniter) is a device containing a pyrotechnic composition used primarily to ignite other, more difficult-to-ignite materials, such as thermites, gas generators, and solid-fuel rockets. The ...
. The igniter is struck by a firing pin when the device is activated. One cartridge releases of oxygen and burns for 5–20 minutes at .Oxygen Generators
/ref> The oxygen is cooled and filtered to remove dust and odours, and released into the space station atmosphere.
See also
*Life support system
A life-support system is the combination of equipment that allows survival in an environment or situation that would not support that life in its absence. It is generally applied to systems supporting human life in situations where the outsid ...
References
{{reflist
External links
* :File:Environmental.pdf (this has a small picture of an SFOG on the bottom left)
SFOG Lessons Learned
Mir
Oxygen
Spacecraft life support systems