Calen was a Major in the Imperial Zentraedi Forces. After the discovery of the Human Research Base Gibraltar, he was dispatched by Breetai and Exedore for a recon mission of the site with . Thus, they decided to dispatch Major Calen and a platoon of Powersuits onboard these Light Assault Transport Carriers. However, Calen instead engaged the Robotech Defense Force at the site as he intended to gain glory by achieving victory over their foes.