NASA mindblown by 340-day experiment on twins — one was sent to space while the other stayed back on Earth

NASA had a rare opportunity to conduct a groundbreaking study that could influence the future of space exploration. Scott and Mark Kelly, twin brothers born in 1964, both had careers as NASA astronauts. In 2015, NASA sent one twin into space while the other remained on Earth, as per LadBible. The goal was to examine how prolonged exposure to microgravity affects the human body. Scott was chosen for the historic mission, spending 340 days in orbit aboard the International Space Station (ISS) while Mark, a former NASA shuttle commander, stayed on Earth, as reported by ABC News.

Scott launched into space in March 2015 with Russian cosmonaut Mikhail Kornienko. NASA said, "The mission’s goal was to understand how the human body reacts and adapts to the harsh environment of space. During the 340-day mission, almost 400 experiments were conducted on the station." The main focus of the study was to understand human spaceflight. With NASA and SpaceX looking beyond low Earth orbit, including the possibility of missions to Mars, it was crucial to examine how space travel impacts the body.

Their identical DNA provided an ideal control group, giving scientists a unique opportunity to analyze how extended time in space affects human biology. Before, during and after Scott’s mission, both brothers underwent rigorous medical testing. Researchers collected blood, urine, stool, and saliva samples. They also conducted vision and cognitive function tests, as well as physical performance evaluations. The results, published in the "Twins Study," uncovered unexpected findings. Despite being in space for almost a year, Scott did not experience major long-term health issues related to prolonged microgravity.

He was taller and lighter than Mark at the time of landing. His immune system remained stable, and his stress levels returned to normal after landing. However, researchers discovered that 7% of Scott’s gene expression changed while he was in space. One of the most surprising discoveries involved telomeres, the protective caps at the ends of DNA strands that generally shorten with age. However, Scott’s telomeres grew longer while he was in space. Since telomeres are associated with aging and diseases such as cancer and heart conditions, this unexpected change caught scientists off guard.

Steven Platts, deputy chief scientist with NASA’s Human Research Program, highlighted the importance of these findings. He said, "The results we've seen show the resilience and robustness of the human body. We've evolved here on Earth in a one-(gravity) environment, we grow up, we train, we do everything here, and yet, when we go into space, our bodies adapt and continue to function and by and large, function extremely well." He also said, "Changes that were seen in Scott, the vast majority of them came back to baseline in a relatively short period of time when he returned to Earth. And those that did not are markers of things we already knew were likely to happen."

Researchers now have a clearer understanding of how the human body responds to space travel and what precautions must be taken to protect astronaut health. "This will guide future biomedical space research and allow us to have a safer journey to and from Mars," Platts concluded. Although the results were promising, further research is necessary. NASA has already approved 25 new projects to examine the effects of prolonged space missions on astronauts, but longer trips are required to really analyze how the space environment affects the human body, as per Science News.