Penhall was a member of SG-2 during the mission to rescue Bra'tac and Rya'c from Erebus. SG-2 accompanied SG-1 and took positions above the death camp, preparing for the attack. Penhall was also a member of SG-3 during the mining survey operation on P3X-403. Penhall and Hanson were assigned as security to accompany Daniel and Teal'c, and they assisted in the search for Lieutenant Ritter after he was captured and killed by the native Unas.
Cross Reference: Colonel Edwards, Erebus, Major Lorne, Lieutenant Menard, P3X-403, Lieutenant Ritter, SG Teams, Lieutenant Woeste
Episode Reference: Orpheus, Enemy Mine