Captain Samantha Carter was promoted to Major in 1999, and promoted again to Lt. Colonel in 2004. Her assignment is to ascertain possible hostile threats, to continue analysis of stargate technology, and to analyze and return materials, technologies and knowledge for further development. She has served in the Pentagon, was previously a flight officer in the Kuwait theater, and has received special training in the F-117/F16.

She in an astro-physics genius, holding a Ph.D. in Quantum Mechanics and is a plasma/particle physics expert. She is also an expert on gate technology, having read every bit of information known to exist and has studied the permutations of the gate symbols at length. When the plug was pulled on her gate research project and she was transferred to another base, she continued her research in private. She was able to resume her obsessive work with the gate when the SG-1 team was assembled. Major Carter is single and unattached. She is fiercely loyal to the SGC, and not only brings her extensive scientific knowledge to the program, but also her military training.