Twin objectives: NASA astronaut takes 1yr mission as Earth-bound brother monitored

NASA astronaut Scott Kelly (left), Expedition 26 commander, is reunited with his twin brother, Mark Kelly on March 17, 2011, following a flight back to Ellington Field, Houston from Kustanay, Kazakhstan (Image from
NASA is set to send an astronaut on a first-of-its-kind mission: Scott Kelly will spend an entire year on the ISS. But it’s also part of the Twins Study program. Mark Kelly, Scott’s identical twin and also an astronaut, is to stay on Earth.

The twins program is aimed at researching the genetic effects and physiological changes of people with almost-identical DNA.

“NASA is venturing into this field of genetic base research because my brother and I are identical twins and our DNA is mostly the same. NASA has a lot of data on my brother for the last 20 years,” Scott Kelly told RT.

Scott (L) and Mark Kelly (Image from

He noted, however, that there are downsides connected with the program for them.

“There are negative effects on our physiology, a lot of them we know how to mitigate and part of the reason for doing this flight is to understand those physical effects better, and understand how to mitigate them, so that we can travel further from our planet than we’ve done before,” he added.

“Risk and reward balance, and not just personal reward, but what it provides our society is worth the risk for me personally, and for my colleagues as well,” Kelly said.

Scientists already know that life in orbit can cause loss of bone and muscle, vision issues, some changes having to do with balance and motion. During the year-long trip and afterwards, researchers will compare the twins’ immune systems, reaction times and the performance of their hearts.

Also, blood and urine samples, MRI images, bacteria from the digestive tracts, are set to be taken from both men, sampled and analyzed, with Scott’s sent to Earth.

The tests are to go on for at least a year after Scott returns to Earth.

A month ago, Mark Kelly told the Guardian about the effects on how they will perceive time, one at the final frontier, the other back on Earth.

“The effect is known as the twin paradox, though it is not actually a paradox, it is a straightforward consequence of the laws of relativity. Essentially, time will pass slightly more slowly for Scott than for me because he will be traveling at a greater speed relative to me,” Mark, who has been on several space missions, said.

Mark and Scott Kelly, 51, are the first siblings to fly in space.

The lift-off for the year-long space journey for Scott Kelly is scheduled for March 27 from the Baikonur Cosmodrome in Kazakhstan.