It is a term that a lot of us are probably familiar with – nature versus nurture. But now, for the first time, research has been conducted into the conundrum on a cosmic scale. And it is all thanks to a pair of identical twins – both of whom are astronauts – and a 2016 mission to the International Space Station that lasted almost a year. The results could well be the next step in a planned NASA voyage to Mars.
New Jersey-born Scott and Mark Kelly are unlike any other astronauts for one very important reason – the 54-year-olds are identical twins. They are the only such pairing – indeed, the only brothers – who have ever been launched into space. And it is thanks to their familial connection that they have played a huge part in the current drive by the National Aeronautics and Space Administration – NASA – to find out more about the effects of space travel on the human body.
In fact, Scott Kelly represents an excellent subject for NASA’s study. The astronaut holds the U.S. record for the accumulated amount of days up in space. Indeed, Scott has logged 520 days in orbit around Earth, with much of that time spent as the commander of the International Space Station. In all, he was in charge of three separate operations on the low-orbit spacecraft. But perhaps the most notable thing about Scott is the total of 340 days that he spent on board the station. And it is not just the length of time that is of interest, it is the research that NASA carried out while the astronaut was up there.
That is because Scott and Mark Kelly underwent a series of trials and experiments that NASA refers to as the Twins Study. And the space agency’s investigation was special for a number of reasons. NASA has researched how space travel can change the body of an astronaut during a standard six-month stay on the International Space Station. But Scott’s 340-day sojourn was the first monitoring of anyone who had spent almost double that time in orbit.
And that was not the only unique factor for NASA. Because Scott and Mark are identical twins, they share the same DNA. Essentially, that meant that the space agancy had a control specimen with which to compare its research into the effects of prolonged space travel on Scott’s body. So while one Kelly twin rocketed off to the International Space Station, the other remained on Earth but both were keenly observed.
Scott left for the International Space Station at the end of March 2016, blasting off from Kazakhstan’s Baikonur Cosmodrome. He arrived back on the surface of Earth on March 1, 2017, almost a year after he had departed. During that time, Scott orbited the planet more than 5,400 times, and took part in three separate space walks.
A total of ten research teams comprised the study into the Kelly twins. Each of these units researched one specific aspect of the changes to Scott’s body, but they pooled their discoveries with the other nine groups. In January, 2018, NASA released the initial findings of its investigations, and the results certainly make for some astounding reading.
The first part of the study showed that some of the effects of Scott’s long-term space travel returned to normal after the astronaut landed back on Earth. These changes were biological, and included stress caused by a lack of oxygen, inflammation of body tissue and a change in nutrient levels. Some factors righted themselves a matter of hours after Scott touched down, while others took more than six months to readapt.
A lot of the biological problems presented by space flight are due to the change in gravity. Human musculature and bone structure can atrophy in the much weaker microgravity of space. As such, astronauts have to undergo exercise regimens before, during and after their time in space to combat these problems. After the space traveller has a chance to adapt back to the Earth’s gravitational pull, many of these problems subside.
But the Twins Study went much deeper into the physiology and psychology of long-term space flight than any research before. The NASA investigation examined the molecular and genetic makeup of the twins to better understand what happens to the human body when it is freed from the confines of Earth. While the findings are still in a preliminary stage, what was discovered is incredible.
For one thing, the telomere structures at the ends of Scott’s genes appeared to have lengthened during his time in space. Acting as a kind of buffer at the end of a chromosome, a person’s telomeres shorten as the subject ages. Essentially, telomeres are caps at the top and bottom of our genetic material. Because DNA does not replicate all the way to the end of our chromosomes, the telomeres are able to absorb damage and keep our genes intact.
While many of his telomeres were observed to have shortened again within a couple of days of Scott returning to Earth, some did not. NASA therefore concluded that prolonged space flight may well change the way that we age. While the research into the implications of this is still ongoing, it is an insight that would not have been discovered without the Twins Study. And there are even more revelations in the preliminary report.
Another interesting aspect of the Twin Study also concerned changes in genetic make up. While more than 90 percent of Scott’s genes returned to normal after a short time back on Earth, some seven percent of them did not. It is thought possible that his prolonged space flight has changed these genes forever. But even more interesting is what exactly these sequences control in the human body.
The genes that were altered by Scott’s time in space deal with the immune system, the formation of bones and how DNA is maintained. Some NASA scientists believe that they reacted because another gene was activated while Scott was in space. This gene has become colloquially known as the “space gene.” Again, however, more research is needed to ascertain that this is indeed what happened.
Meanwhile, further scrutiny of the results showed that Scott underwent a somewhat strange reaction to returning to terra firma. While the astronaut was up in space, his cognitive functions did not seem to be impaired at all. In fact, compared to his Earth-bound brother, there was no relevant difference. But that soon changed upon Scott’s return to the planet surface.
It transpired that when the returning Scott was studied, the accuracy and rapidity of his cognitive abilities experienced a decline. It is possible that this was due to the veteran astronaut having to adapt once more to the different gravitational pull of Earth. It is also possible that a heavy workload after the mission could be to blame. Whether or not it proves to be a long-term factor will likely be revealed by NASA after more investigation.
And it is fair to say that there is a great deal more to emerge from the Twins Study. According to NASA’s roadmap for the project, further information is set to be published later in 2018. But it certainly looks like the results are going to reveal even more about how human bodies react to space. Nevertheless, interplanetary exploration enthusiasts wanted to know what results of the Twins Study so far meant for the future of space travel.
According to Dr. William Paloski, director of NASA’s Human Research Program, the future is looking bright. Paloski’s department has been instrumental in the Twins Study. In an exchange with the educational website How Stuff Works, Paloski explained that the preliminary findings of the research all point to one exciting outcome. He revealed that a manned mission to Mars is a distinct possibility.
The NASA executive said, “Nothing presented… suggests that future missions to Mars may be more difficult for the space explorers than we previously expected.” Paloski also confirmed that “more insight is expected to be revealed later this year.” Which leaves us with one question to answer – what happened to the Kelly twins?
Scott hung up his astronaut suit for good just a month after returning from his mammoth stay on the International Space Station. He now works as a United Nations Champion for Space – a sort of ambassador role, advocating for space travel. Despite taking part in the Twin Study, Mark actually retired from NASA in 2011. He is currently active in the private space travel sector, working with World View Enterprises and Elon Musk’s Space-X. But whatever the Kelly boys’ future, the twin’s contribution could well lead to a new era of safer space travel. And one which will take human beings farther into the Solar System than ever before.