Neil Armstrong became the first man to step on the Moon on July 20, 1969. Millions of people followed the feat throughout the years. Among all the children who at that moment dreamed of flying into space, were twins Scott and Mark Kelly, who were merely five years old at that time. Almost half a century later, Scott fulfilled his dream. He became the first American to spend almost a year in space.

On March 27, 2015, he arrived at the International Space Station (ISS) with the mission of spending 340 days there and determining if the human body could support a trip to Mars. “The purpose was to see how the body responded after being subjected to weightlessness, radiation and high levels of carbon dioxide,” explained Kelly on Monday in the presentation of his book Resistencia, a year in space at the headquarters of the Telef├│nica Foundation in Madrid.

NASA studied how the trip affected his health by comparing it to that of his twin brother, who stayed on Earth. Traveling to space causes a loss of muscle mass, visual problems, and circadian rhythm disorders. In the case of Kelly, it also had its positive effects: “My telomeres, the ligatures that join the chromosomes, have lengthened with respect to Mark’s. That was not expected, because, with age, they contract, and they figured that in my case, they would get worse.”

The astronaut does not see a trip to the red planet in the next ten years. “I’m not optimistic about the political environment we have,” he said. The American president, Donald Trump, gave the green light in December to a new space strategy that aspires to return to send astronauts to the Moon. For Kelly, the Moon is “a good place to practice before going to Mars,” but “returning is not a serious proposition.”

Prior to this mission, this American had already been in space three times. He made an emergency repair of the Hubble telescope, brought spare material to the ISS and stayed 159 days in this same station. Of the latter, he returned with eye problems and prostate cancer that he managed to overcome. For him, it is essential to continue investing in space exploration and learning new things. “If we were not curious as explorers, we would continue to live in the jungle,” he says.