During the Zeon attack on the colony where the first Gundam was being tested he is sucked out into space after an explosion breaches the hull of the facility. Fortunately he survives as Tem was wearing a spacesuit. However, due to a prolonged exposure to hypoxia as he was rescued after his suit's oxygen reserves were almost depleted, Tem's brain is damaged permanently beyond recovery and develops symptoms of dementia.

Later in the series his son Amuro Ray visits him and becomes shocked by Tem's mental condition. Sometime afterwards a crazy and disturbed Tem is last seen falling from the stairs of his apartment and his final fate is left uncertain.