The LEAP-X (Life Extension and Prolongation) Program was a U.S. military experiment to keep a human in a state of veritable immortality via machines. Since the time of its inception, the experiment was still at its infancy. Its original intention was to create a living bio-suit to preserve a body after normal expiration. However, due to the increased power usage and multiple special components required, it could only accommodate up to 15 pounds worth of organic matter.
John-Caleb Bradberton, founder of the Nuka-Cola Corporation was able to learn of LEAP-X's existence, due to his powerful influence in the American government. He would later bargain with General Braxton to gain access to the LEAP-X project in exchange for supplying his company's resources into Project Cobalt. However, the experiment was only able to preserve his head for the next two centuries.