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One Half Of NASA's Twin Astronaut Study Is Running For The Senate


Stephen Luntz

Stephen has a science degree with a major in physics, an arts degree with majors in English Literature and History and Philosophy of Science and a Graduate Diploma in Science Communication.

Freelance Writer

Astronaut Mark Kelly, who was part of an experiment that has been groundbreaking in what it revealed about the effect of space on the human body, has announced he is running for the Senate. NASA/JPL/Public Domain

Mark Kelly, astronaut, naval aviator, and husband to former member of Congress Gabrielle Giffords, has announced he is running to be US Senator for Arizona, putting science at the center of his campaign. Kelly's biography has so many features media outlets don't know which to highlight, but to IFLScience he is most notable for being half of a major study with his brother Scott, also an astronaut.

Scott and Mark are identical twins. Through some combination of their identical DNA and a shared childhood environment, both became astronauts and the only twins to both reach space. NASA saw the potential of the situation, and used Mark – whose four voyages beyond the atmosphere totaled 54 days – as a comparison for the changes Scott experienced over almost a year in space.


Life in microgravity, and increased exposure to cosmic radiation, changes people. Understanding this process is essential if we are ever to reach Mars, let alone the outer Solar System, safely. Sending just any half of a pair of identical twins would be a very expensive way to investigate this, but Scott's impressive record as an astronaut meant he would be an asset to the International Space Station anyway, so it made sense to learn more while he was there.

Observable effects, such as Scott's increased height during his time without gravity weighing him down, proved temporary, but NASA also famously observed changes to his DNA, some of which did not match Mark's after Scott's return to Earth. The data from the study is still being analyzed, but included some surprising and unexplained findings, such as the telomeres at the end of Scott's chromosomes extending while he was in space, before shortening again on his return.

When running for office, being the stay-home part of a great experiment may not be much of a qualification, but Mark Kelly has plenty of others. His master's degree in aeronautical engineering would make him one of the few senators with a STEM background, and his naval combat and NASA careers both included numerous medals for distinguished service.

When Giffords was shot in the head by a right-wing terrorist and barely survived, Kelly commanded the Space Shuttle Endeavour's last mission four months later. Giffords and Kelly subsequently established Americans for Responsible Solutions to push for reform of gun laws.


Kelly has also demonstrated his ability to make important political points succinctly, providing knock-out responses on Twitter to President Trump.

Kelly is seeking to be the Democrat candidate to run against Martha McSally, who, after being defeated last year for Arizona's other Senate seat, was appointed to fill the vacancy created by John McCain's death. He articulates his reasons in the video below. 



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