Harper

S.G.C. officer who travelled to P3X-439 with SG units 1, 3, and 5 to attempt to recover one of the Ancients' repositories of knowledge. He defended the gate alongside Colonel Reynolds until the mission was completed, fighting off Al'kesh and Death Gliders sent by the Goa'uld Anubis.

It is likely that Harper is commander of SG-5, as he was included in a briefing with Reynolds and O'Neill.