Data is an android who was found and re-activated by the crew of the USS Tripoli. This took place on Omicrom Theta IV in 2338. After his activation Data goes through a rough patch but the crew of the Tripoli inspire him to eventually join Starfleet. He enters the Academy in 2341 after a legal decision is made stating that Data is a sentient life form. The only person to vote against Data's entry is made by Bruce Maddox, a member of the Daystrom Institute.

Data has problems with Maddox again in 2365 when Maddox wants to perform tests on him to try and re-create the work achieved by Data's creator Dr Noonien Soong. Data attempts to resign rather than be forced to undergo the tests. Maddox forces an inquiry at Starbase 173. But the Judge Advocate states Data is NOT Starfleet property and upholds his sentient individual rights.

At the Academy Data finds the exams and work demanding but elementary, His biggest problems occur with social interaction. He graduates with honors in 2345. And spends 3 years as an ensign and gets his first promotion in 2348 to Lt. Junior grade.

In 2364 he has achieved the rank of Lt. Commander and is assigned to the Federation flagship the USS Enterprise NCC 1701-D. His post is the ships Operations Chief and also its 2^nd Officer, which puts him 3^rd in command after Picard and Riker.

In 2367 Data briefly takes Command of the USS Sutherland when Starfleet organises a blockade of the Romulan / Klingon border after a Klingon civil war breaks out.

8 years into his Enterprise service the Enterprise is destroyed by the Durass sisters and he like most of the Enterprise D crew transfer to the new Sovereign Class ship, The USS Enterprise NCC 1701-E.

In 2373 Data is tempted by the Borg into betraying Starfleet and helping them assimilate humanity. But its thanks to him that the Borg plan fails.