Fifteen years later, he applied to Starfleet Academy and was accepted on his first try. He completed his Academy training, excelling in the Medical/Sciences departments, as well as Planetary survival and Security procedures. He then applied to the Military Operations Command Training School, where he studied for 2 years until he was offered a position on the USS Hood as a Xenobiology student. He impressed his Department head so much, she recommended in her logs that he be given a command of his own section. He then became the youngest person to command a section on a starship. He was 26 years old.

After another year on the Hood, he completed his Cadet Cruise with Honors and was offered a commission on the USS Farragut.

He was promoted to Ensign and given the Xenobiology department to command. There he served in the clean-up effort at Veridian III of the Enterprise-D. Once, he met Captain Picard, just as he was walking into the transporter room to beam down for his shift at the crash site, but didn't get a chance to talk to him. At that moment he realized he desparately wanted to be in command of his own ship, so he could be in the company of a man like him.

The following year, he heard of several openings on the USS Galaxy, and knew that this was the perfect opportunity to achieve his aims faster. Mitchell was soon promoted to Lieutenant jg. on board the USS Galaxy. Less than a year later he became the Galaxy's Chief Science Officer and a full Lieutenant.

Within 2 months of serving on the Galaxy as Chief Science Officer, Lieutenant Mitchell was relieved of duty for personal reasons and spent a year at Starfleet Medical undergoing counselling and psychological testing as a result of manic depression and a resurfacing of memories blocked out by intense shock.

At the completion of his rehabilitation near the end of 2374, Mr. Mitchell was deemed fit to return to active duty on a limited basis, so he was assigned to the Starfleet Sciences Division on Earth, specializing in Xenobiology. With the outbreak of the Dominion War and subsequent closure, Starfleet was then able to focus on the Borg threat once again, and began sending out many of its Earth-based officers to starships to serve as specialists in their areas and assist the Science teams in their efforts. Mr. Mitchell was one of these officers, and assigned to his previous vessel, the USS Galaxy, in 2377.

At the end of 2377, James was put in for a promotion by his department head, Commander Peterson. James was promoted to Lieutenant Commander and formerly made the Galaxy's Assistant Chief Science Officer for his excellent work and "team player" attitude upon returning to the starship he formerly served as CSO on. In a rather unexpected turn of events, Commander Peterson was relieved of his duties on board the USS Galaxy and reassigned by Starfleet Command along with several other officers (including Captain Price). James was promoted to Chief Science Officer by the new CO, Captain John Brhode.