Astronaut Scott Kelly launched to the International Space Station on Friday, while his twin remains on Earth for genetic testing Astronaut Scott Kelly has blasted off into space for a yearlong ...

For 340 days, he circled Earth inside the International Space Station, the longest any American ... his identical twin, Mark Kelly. Scott and Mark are the only twin NASA astronauts in history.

When Scott Kelly (right) goes to the International Space Station in 2015, he and his twin brother Mark (left) will participate in tests to study how spaceflight affects the body. Left image ...

Two NASA astronauts plan to participate in a 6-hour, 35-minute spacewalk Thursday to upgrade the International Space ...