Gigalt Gangaragash

A veteran astronaut, formerly of Technora Corporation's Debris Section, and currently with the Orbital Security Agency. He is Hachimaki and Hakim's EVA instructor. Gigalt contracted cancer (most probably lung cancer) from prolongued exposure to radiation from his many EVA missions. Gigalt only appears in the anime. Gigalt has a habit of bestowing nicknames on work partners, including Hachimaki's nickname of "Hachi," which is the only one which stuck. The last two nicknames he bestows are "Angel" to Ai Tanabe, and "Artemis" to Nono while she keeps him company at Tranquility City Hospital.

(Source: Wikipedia)