Project: P.E.G.A.S.U.S. "Potential Energy Group/Alternate Sources/United States" was founded with the idea of researching alternate forms of renewable energy, but has also been used as a prison for super-powered individuals. The location of this facility is described as being in the Adirondack Mountains in New York State. Headed by Dr. Myron Wilburn, it quickly found itself at the center of much unwanted attention when the structure came to house a Cosmic Cube, a Nth Projector, and the Serpent Crown and several other artifacts of great power. Soon the Project also began testing on metahuman specimens, mostly career criminals, but others, such as Aquarian and Dazzler were also tested extensively, yet humanely. The Project became little better than a prison to many of the specimens such as, Klaw, Solaar, and Nuklo, and as such they sought escape.
Shortly after the project's completion, Quasar was offered the position of Head of Security, based on his service record with the army, SHIELD, and a recommendation from Captain America. He served in this role admirably for several months, with the Thing's help he, along with Thundra, Goliath, and Aquarian saved the world and potentially the universe from Dr. Thomas Lightner, who had turned himself into a living singularity, calling himself the Nth Man.
Months later, the entire Project was taken over by the Serpent Crown. Only the intervention of several outsiders averted a complete disaster. Quasar blamed himself and tendered his resignation. He was soon replaced by Blue Shield, who held the position for several years was just recently replaced by Darkhawk. When the Squadron Supreme were exiled from their universe by Dr. Lightner, they made the Project their temporary home.
Quasar returned briefly to save the Project from the sentient alien armor that Iron Man brought back with him from Battleworld (Secret Wars II) as it attempted to consume the entire Project. Quasar managed to fly it down the magma tap which destroyed it.
During Secret Invasion, the project was inveded by a cadre of Skrulls who recognized the threat that PEGASUS meant to their invasion since there were devices held at Project PEGASUS was could litterally burn the Skrull fleet out of the sky. Security Chief Darkhawk and Nova the last member of the Nova Corps, along with the remaining Guardsmen managed to defend the Project valiantly along with the help a newly reborn Quasar.
Ultimate Universe - Earth-1610
The Project Pegasus of the Ultimate Universe is located in Devil's Point, Wyoming and is run by S.H.I.E.L.D. agent Wendell Vaughn. It houses various items confiscated by S.H.I.E.L.D. which have mysterious power or unexplained origin.