Returning to Saipan on the 19th, she provided fuel, water, and ammunition to ships of the Marianas invasion force, took on empty brass, and repaired landing craft. Early on the morning of the 24th, seven of her tank lighters took part in the initial landings on Tinian. On the 28th, "Thuban" got underway and steamed in convoy via Eniwetok to the Hawaiian Islands, arriving at Pearl Harbor on 10 August. There, following amphibious exercises off Maui, she embarked Army troops; rendezvoused with TG 33.3; and headed via the Marshalls for the Admiralty Islands, arriving at Manus on 3 October.