A sergeant in the Military Assault Command Operations detachment that joins Enterprise for the Xindi mission, played by Nathan Anderson and seen in the third season.
Kemper is one of the MACO soldiers who come aboard Enterprise NX-01 under Major Hayes before the ship enters the Delphic Expanse. He was played by Nathan Anderson.
He is introduced in The Xindi, where he chats with the Starfleet crew in the mess hall and mentions growing up in Duluth, and then takes part in the rescue of Archer and Tucker from a mining colony. He is seen again in Anomaly, when raiders board the ship.
He returns in Countdown as a member of the team Hayes leads to recover Hoshi Sato from a Xindi-Reptilian ship, the mission on which Hayes is killed.