Parker was a Tau'ri military officer and member of the Atlantis expedition. Upon arriving in Atlantis and discovering that they were running out of power, Parker was one of the people who went to Athos looking for a power source or safe harbor. Sumner ordered him and Smitty in gate duty. He was among men who were not taken and returned to Atlantis. He later took part in rescue team under Major John Sheppard. (SGA: "Rising")