Superman's amazing abilities are powered by Earth's yellow sun. However, when exposed to the rays of the red sun, he is significantly weakened and loses his powers over prolonged exposure.
In one classic story, Superman is hit by a wave of radiation from a dying red sun, leaving him powerless. To still perform his duties as a Super Hero, he creates a flying vehicle from the hardest metal in the universe. This vehicle, known as the Supermobile, can withstand any hit, mimic the majority of Superman's powers, and fly him anywhere!