Hank Henshaw was an astronaut at NASA until a solar flare hit his space shuttle during an experiment in space, damaging the ship and the crew. Henshaw and the crew, including Henshaw's wife, found that their bodies had begun to mutate and, after returning to Earth, Henshaw's entire crew either perished or eventually committed suicide. After learning that Superman had thrown the Eradicator into the sun in a battle during the space shuttle experiment, Henshaw blamed Superman for the solar flare and the accident. Before his body completely disintegrated due to the radiation exposure, Henshaw was able to save his consciousness. Using NASA communications equipment, Henshaw beamed his mind into the birthing matrix which had carried Superman from Krypton to Earth as an infant. He created a small exploration craft from the birthing matrix and departed into outer space alone. Becoming increasingly mentally unstable, Henshaw used Superman's birthing matrix to create a body identical to Superman's, albeit with cybernetic parts. He returned to Earth to kill Superman, only to discover that Superman had already died during Henshaw's absence. Following Superman's eventual resurrection, Henshaw would not only become a recurring adversary of Superman but of Green Lantern as well. Hank Henshaw became a member of the Sinestro Corps during the Sinestro Corps War.