- "This is Colonel William Ronson, commander of the Prometheus."
- ―William Ronson[src]
During the Prometheus shakedown cruise, Ronson greatly irritated Colonel Jack O'Neill by putting his crew -- and SG-1 -- through an extensive series of readiness drills, during which he kept SG-1 off the bridge and assigned them to assist in damage control. When O'Neill protested his team's relegation to the sidelines, Ronson explained that he wanted his crew to be able to depend on each other after SG-1 had departed with Jack stating that he could respect that.
During that mission the Prometheus hyperdrive was damaged, rendering it unable to complete its mission or safely return to Earth, Ronson ordered the vessel to the nearby planet of Tagrea at the suggestion of Jonas Quinn. After that jump necessitated the ejection of the hyperdrive core, stranding them, he landed the ship while SG-1 sought the Tagrean's aid. During his time there, he was highly protective of his ship and crew but reluctantly followed O'Neill's approach to handling the turmoil that resulted from their arrival. (SG1: "Memento")
The following year, while the Prometheus was making its way back to Earth using a hyperdrive salvaged from an Al'kesh, Ronson agreed to inspect a mysterious gas cloud at the behest of Major Samantha Carter. While doing so, the ship was attacked by an unfamiliar alien vessel, and Ronson disappeared along with the rest of the vessel's crew save Carter. He reappeared, along with his crew, after Carter offered to help the aliens escape the gas cloud in exchange for their return. (SG1: "Grace")
Little is known about what happened to Ronson after the episode "Grace", it is assumed that he was either reassigned or that he retired. In the aftermath, Colonel Lionel Pendergast succeeded Ronson as commander of the Prometheus.