Commodore Travers was the commanding officer of the Hyperion III. He helped the Sixth Doctor save his ship from the Black Hole of Tartarus, stop Rudge's hijacking attempt and defeat the Vervoids. Before this, he had had an unchronicled encounter with the Doctor. (DW: Terror of the Vervoids)
In an alternative timeline in which the Valeyard killed the Sixth Doctor and acquired his seven remaining regenerations, the Valeyard and his companion Ellie Martin travelled to Hyperion III in place of the Doctor and Melanie Bush. The Valeyard left Travers and his entire crew dead and left the "augmented aubergines" to their own devices. This incident was observed by the Time Lord Vansell, the coordinator of the CIA. (BFDWU: He Jests at Scars...)