NASA senior research scientist Jacob Bloomberg once described these tests as "very operation-oriented and [...] related to different aspects of the mission and activities an astronaut would need to do after landing on the surface of Mars." The scientists will study how Kelly's body changed after spending one straight year in space in an effort to understand the impacts of long duration, deep space missions on the human body. His results will most likely be compared with his twin brother's who stayed here on the ground as part of the agency's "Twins Study."

NASA TV is airing Soyuz TMA-18M's landing starting at 10:15AM ET. You'll be able to watch everything, from the spacecraft's deorbit burn and module separation as it enters the atmosphere to the moment it touches down. If all goes well, the Soyuz spacecraft will land in Kazakhstan at around 11:25PM ET.

Update: And the landing is successful! The Russian control center doesn't have a great view in the live feed, but NASA's Twitter account and the voiceover have confirmed the capsule is down safely in Kazakhstan. We're expecting to get live TV from the landing zone "as soon as possible."