Most people set their sights on big ambitions as a kid. For those youngsters who dream of being in the military, it typically includes visions of becoming a fighter pilot, a ship commander or Navy SEAL.

But for one California resident, those lofty goals weren't nearly enough.

Dr. Jonny Kim enlisted the Navy in 2002 and successfully made it through BUD/s and onto SEAL Team 3. During his service in the SEALs, Kim worked as a combat medic, sniper, navigator and point man on two deployments.

Kim completed more than 100 combat missions during his time in the Middle East, earning a Silver Star and Bronze Star with Combat "V."

Navy SEAL Jonny Kim takes a moment for a photo op while on a combat deployment.

During Kim's first combat tour, he lost a fellow SEAL which helped steer him towards a career in the medical field.

"The moment I knew I wanted to go into medicine was during my first deployment to Ramadi which is when one of my best friends was shot," Kim has said. "After doing everything I could for him, securing his airway, controlling his bleeding, there wasn't much more I could do for him but watch the spectacular team of emergency medicine physicians save my friend's life."

Kim decided to complete one more deployment with the SEALs before heading off to college to pursue his medical career.

He attended the University of San Diego earning a degree in mathematics and then a Doctorate in Medicine at Harvard. According to NASA, Kim received an officer's commission in the Medical Corps following his graduation.

Kim went on to perform his residency at Massachusetts General and Brigham Women's Hospital in Boston for emergency medicine .

Dr. Kim during his ER residency. (Source: Pat Tillman Foundation/Screenshot)

In June 2017, Kim received some incredible news — he's one of 12 to be selected for the 2017 NASA Astronaut Candidate Class. The training will take up to two years before he could become a fully certified astronaut.

Soon, Dr. Kim could be wearing a space suit instead of his medical scrubs.

NASA astronaut candidate Lt. Jonny Kim (Source: NASA)

Check out the Pat Tillman Foundation's video below to hear Dr. Kim's story for yourself.