(CNN) -- Nearly five months of cramped living in zero gravity will come to an end Thursday for one American astronaut and two Russian cosmonauts aboard the International Space Station. Their Soyuz capsule is set to undock at 8:30 p.m. ET, and land less than three and a half hours later in Kazakhstan. Soyuz modules are vital to the Russian space program. They are launched into space as capsules atop a rocket, and are capable of landing on land, not requiring a body of water to splash down in. A Soyuz carried the first ever crew to the ISS in November 2000, according to NASA. One is docked there at all times, in case the crew needs to leave in an emergency.
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NASA: The trip back to Earth should take less than three and a half hours
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One American and two Russians will land just before midnight
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Russian Soyuz space modules have proven very reliable
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It is the standard transportation mode to the ISS after a deadly space shuttle crash
The undocking of the @placeholder will mark the beginning of the 35th ISS mission, which awaits the arrival of two more Russian cosmonauts and an American astronaut in two weeks.