From Halopedia, the Halo wiki
He was the youngest of the bridge crew and had seen more battles in four years than most people had in an entire lifetime. It took its toll on Yang, exhausting him to the core.
He was at his station during the Battle of Earth and traveled to Installation 05 aboard the ship as it followed the UNSC In Amber Clad pursuing the High Prophet of Regrets ship. He was also aboard when the Dusk returned to Earth and was subsequently sent out to Onyx to provide intelligence during the Onyx Conflict. After the battle his commander, Commander Richard Lash, ordered the ship back to Earth to evade destruction from Onyx.
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