Identical "Space Twins" Astronauts Launch A Groundbreaking Experiment Only They Can Accomplish

The experiment is expected to help scientists identify the physiological changes that space travel causes to the human body.

Mark Kelly, Scott Kelly

A pair of twin brothers is participating in a unique experiment to analyze the affect of space tourism on human body by sending one sibling to space and keeping the other on Earth.

It means Scott Kelly will soon fly off for the International Space Station, while his twin sibling Mark Kelly will spend significant time under the observation NASA scientists. With two brothers in completely different environments, they believe a better comparative analysis of space travel's toll on human body could be estimated.

"This is really going to help us learn a lot about the negative effects of space on our human physiology and then hopefully we'll figure out how to mitigate that," said space-bound Scott earlier this year.

Astronaut Scott Kelly Will Test His Limits on Epic One

"It's a way to start using 21st century medical technology to understand what happens to people in long-duration space flight," added Dr. John Charles, head of NASA's Human Research Program.

The experiment has been arranged with an eye on the expected emergence of space tourism as well as planned trips to Mars.

While the findings of the research are years away, one thing is certain that when Scott returns – he'll be slightly taller Mark due to lack of gravity in space, although he will shrink back to his normal size in time.

 twin brothers are about to help NASA make history

"This time hopefully it will last long enough so that when I get back to the U.S. I can look down at him," Scott said jokingly about the height effect.

The experiment kicks off on March 27 in Kazakhstan.