Becoming an astronaut is a popular career aspiration ... As a Special Warfare Operator, Kim participated in more than 100 combat missions as a combat medic, navigator, sniper, and point man ...

Astronauts experience decreased muscle mass, strength, and endurance because moving around requires reduced work from the legs and back. As a result, the muscles can begin to weaken or atrophy. To ...

He first became a medical doctor and then a Navy SEAL, serving more than 100 combat missions. He's also the first Korean-American astronaut to journey to space. "It really gives them a sense of ...