Careful Spectator readers may recall this writer’s review of "Endurance," Scott Kelly’s book about his 11 months living on the International Space Station (ISS) zipping around the Earth at 17,000 miles an hour. His journey was part of the $1.5 million NASA Twins Study when medicos compared his physiological changes with his identical twin brother, Mark Kelly, who is a retired NASA astronaut.

Cornell Alumni News magazine interviewed Weill Cornell Medical School Professor Chris Mason about preliminary results of his work on the study plus some reporters’ misinterpretations plus some funny tweets from the subjects that created headlines that space travel “had transformed an astronaut into something other than human.”

Mason is a Weill Cornell Medical School associate professor of physiology and biophysics who was one of 10 principal investigators on the study. His study is entitled “The Landscape of DNA and RNA Methylation Before, During and After Human Space Travel.” Before Scott Kelly launched in late March 2015, he and Mark, who was Cornell’s 2015 Convocation speaker along with his wife, former Congresswoman Gabrielle Giffords (who earned her Cornell Master's Degree in Regional Planning in 1997) started a battery of physical tests and the brothers continue to have exams since Scott’s return.

In winter 2018 Mason presented preliminary findings at NASA’s annual scientific meeting. Mason hypothesized that space travel "had affected Scott’s general expression — how the information in his DNA changed" likely due to such factors as radiation, dietary changes and the effects of zero gravity on the human body. While most of that expression had gone back to normal after six months on Earth, seven percent of it, relating to such areas as the immune system, DNA repair, bone formation and the processing of oxygen and carbon dioxide, was still altered.

That finding, reported in a NASA press release that was later clarified, prompted the Daily Mail to declare that Scott “now has different DNA to his identical brother.”

Things got crazy from there, the Alumni News reported. Mark Kelly tweeted “I used to have a twin brother but then he went to space for a year.”

The brothers Kelly were joking, of course, but having fun as headlines exploded into people posting “Seven percent of his DNA changed, he’s like an alien.”

As Mason noted, the DNA differences between humans and chimps is a mere two percent. “So if seven percent of his DNA had changed, he’d be a different species,” Professor Mason tweeted.

The work will probably form the foundation of multiple scientific papers in the coming years, Mason said. But understanding how changes in genes may affect human health remains in its infancy: “We had only two subjects, so by its very definition, this is the first outline of the molecular landscape of what changes in the body in space,” he said. “It will not be and cannot be the definitive guide.”

Mason now wants to expand the work to include another 30 astronauts over the next seven years. Lacking twins the subject would have their gene expressions compared before and after space travel. He’s also applying the tests’ protocol to sibling sets in which one twin visits extreme environments on Earth such as climbing Mount Everest.

“We’re trying to put the stress of spaceflight in the contexts of ‘What do we see for other stressors on the human body?’”

Ultimately the team’s investigations could have implications on Earth and off. Studying how genes respond to the stresses of space travel could offer insights into such topics as aging, cancer, and circadian rhythm function, according to Mason.

As NASA contemplates long-range space travel such as a mission to Mars the research could influence how future generations of astronauts live and work. “This could helps us understand how to design a space station so it can be a healthy environment,” Mason says. “As for the long-term goals, the sky’s the limit. NASA is planning to send humans to Mars and beyond.”

Mason is a life-long astronaut fan. As a kid he attended space camp twice and calls working on NASA research “very much a dream come true.” Even the misinterpretation of his finding had something of a silver lining: it got the public talking about the science of space travel, Mason said.

“I love it when people are excited about and thinking about humanity’s big dreams, a long-term vision for our species and for technology and what we can do as people.

“I wish it happened every day,” Mason said.


The Canisteo writer’s weakly Spectator column has little to with his license to fly small airplanes that are called “bugsmashers,” in the parlance of professional pilots. But astronauts will always be his heroes.