Peter Grodin was an engineer and advisor to Dr. Elizabeth Weir at the Atlantis base with the Atlantis Expedition. Grodin was British, held a PhD, and was a scientist. While assigned to the Atlantis outpost in Antarctica, Grodin studied the Ancients' drone weapons. He was efficient and considerate, often taking Weir's needs ahead of his own. He was also versed in wormhole physics. (SGA: "Rising")
After the Expedition had settled, Grodin worked with Weir to ensure everything was set up, including the proper placement of supplies, quarters, and the removal of all the dead plants. (SGA: "Hide and Seek")
He was killed in the Ancient Defense Satelite after it destroyed a Wraith hive ship. (SGA: "The Siege, Part 1")