Late Tuesday night, as many in the United States were getting ready for bed, three space travelers were plummeting back to Earth after having departed the International Space Station just a few hours earlier. Touching down in Kazakhstan around 10:25 a.m. local time (11:25 p.m. Tuesday EST) in their Soyuz TMA-18M spacecraft, the return of cosmonauts Sergey Volkov and Mikhail Kornienko, and astronaut Scott Kelly brought an end to ISS Expedition 46 and the latter two spacemen’s One-Year Mission.
In the name of science and exploration, Scott Kelly and Mikhail Kornienko spent a total of 340 days aboard the International Space Station, and made history in doing so.
As part of NASA’s long-term efforts to send humans to Mars in the 2030s, determining the effects of extended spaceflight on the human body is crucial if humans are to survive the almost three-year long round trip.
Amongst the nearly 400 experiments conducted during their extended stay, Kelly and Kornienko conducted several medical self-examinations to study fluid shifts in the body due to weightlessness associated with eye sight changes and intracranial pressure. Understanding obstacles such as these fluid shifts, radiation exposure, or the loss of bone and muscle mass associated with long durations in microgravity will help further the development of technologies that will ultimately bring humanity to the red planet.
More than the benefits reaped from the multitude of information to be gathered by a year’s worth of spaceflight, however, is the bonus attributed to Scott Kelly’s identical twin brother and retired astronaut, Mark Kelly. Serving as an exact genetic basis for comparison, the brothers underwent a myriad of medical tests prior to the beginning of the One-Year Mission, which will enable scientists to compare the two on a cellular level. Fresh off the space station, now that Scott has returned, his mission is far from over.
John Charles, chief scientist of the NASA Human Research Program, states, “For the One-Year Mission research, we will be collecting post-flight medical data three months and six months after [Scott] is back on Earth. For the twins study research, we will continue to collect data as far out as a year after his return. The post-flight data are as important as the in-flight data to help us learn how to send humans safely to Mar and return them safely to Earth.”
Holding the record for longest consecutive flight aboard the ISS, Kelly and Kornienko saw their fair share of excitement.
The pair witnessed the arrival six resupply vehicles during their mission, including the Japanese HTV-5, three Russian Progress ships, SpaceX’s Dragon, and Orbital ATK’s Cygnus craft. Kelly performed three separate EVAs to Kornienko’s one, accumulating 17 hours and 20 minutes, and 5 hours 31 minutes, respectively, outside the station. The first food grown and eaten in space, as well as the first flower to bloom in space both occurred during their stay. In total, Kelly and Kornienko traveled over 230 million kilometers, and completed 5,440 orbits around Earth; giving them the chance to witness twice that in sunrises and sunsets. Many of which Kelly shared with the rest of the world; or at least his social media followers.
Posting a total of 738 pictures to his Instagram account between the time he arrived on the station until his departure, Kelly gained a massive social media following. Several past and present ISS crew members have maintained active social media accounts, and post regularly with hashtags such as #EarthArt, or #HelloEarth. With 975k Twitter followers and 931k Instagram followers, Kelly’s account grew so popular the New York Times ran an article featuring many of his photographs.
Following tradition aboard the International Space Station, a change of command ceremony took place the day before Exp. 46’s undocking. Clad in black shirts, the outgoing crew said their goodbyes to their Expedition 47 companions after Commander Kelly said a few words commemorating the occasion; relinquishing command of the station to NASA astronaut Tim Kopra.