Union Aerospace Corporation

The Union Aerospace Corporation (UAC) is a fictional conglomerate in id Software's science fiction video game series Doom, focused on military-industrial research. The corporation is depicted to be involved in advanced weapons development, biological research, space exploration and teleportation. The company employs former marines as private security contractors. Set in the 22nd century, the UAC is shown to have access to research facilities on other planets and moons within the Solar System, such as Mars, Phobos and Io. In the video games, the UAC's research into teleportation unwittingly allows for the forces of Hell to invade from their realm and attempt to take over humanity.

The UAC is first introduced in Doom, in which the UAC's experiments facilitate a demonic invasion of UAC bases on Mars and its two moons. Although the UAC's role is drastically reduced in Doom II: Hell on Earth, the UAC return in Final Doom with teleportation research facilities on Earth and the moons of Jupiter. The corporation is at the forefront of the story in Doom 3, with its operations on its Mars base being revealed during gameplay as opposed to simply being presented in the game's backstory. In the Doom film, the UAC focuses on genetic experimentation, resulting in mutated humans being the principal threat as opposed to researching teleportation, which led to the game's influx of demons.