Massa was a male Duros with green skin who served as an admiral in the fleet of the Alliance to Restore the Republic during the Galactic Civil War against the Galactic Empire. Shortly after the Battle of Hoth, Massa learned that the Empire was constructing a second Death Star above the moon of Endor while attending a classified meeting of the Alliance's leadership in a Rebel safe house on the planet Zastiga. When Admiral Gial Ackbar first revealed a hologram of the new Death Star to the meeting, Princess Leia Organa mistook the image for one of the original Death Star, but Massa pointed out she must be wrong as it had been destroyed at the Battle of Yavin. Once they were informed it was a new station entirely, Massa doubted that the fleet would be able to destroy the Death Star; however he was later proven wrong at the Battle of Endor.