The SOLG (Strategic Orbital Linear Gun)
It's a military attack satellite, Currently only a conecpt. Capable of launching conventional and nuclear warheads, it was specifically designed to launch hi-tech MIRV (Multiple Independently Targetable Re-entry Vehicle) missiles.
The SOLG is completely unmanned. Its four arms provide stability in orbit, its main length made up of a magnetically accelerated rail gun and six lines of three solar panels each providing power to its magnets.
Despite the high-priority status of the project, the lack of funds from sponsors left it unfinished in orbit until NASA included it as part of plans to build a second International Space Station.