'''Vika''' or '''TGK''' is an oxygen generating system for spaceflight.<ref name=ellis>[https://www.nasa.gov/pdf/602090main_44s_international_life_support.pdf Kerry Ellis - '''International Life Support''' - Ask Magazine]</ref> It is a SFOG, or solid-fuel oxygen generator, a kind of [[chemical oxygen generator]].<ref name=ellis/> It has been used on the retired [[Mir]] space station and the [[International Space Station]].<ref name=ellis/> It was originally developed by [[Roscosmos]] to supplement the ''Elektron'' oxygen system on ''Mir''.<ref name=ellis/> A Vika modulele, also known as a "candle", contains about one liter of [[lithium perchlorate]] and can provide oxygen for one person for 24 hours.<ref name=ellis/>
After being adopted for use on the ISS, it had the NASA name '''SFOG''', but they also sometimes use the Russian acronym TGK.<ref name=ellis/>
