The Discovery Center was a scientific research facility on Varnex, a moon of planet Mestiko. It was established in 2283, at the prompting of Dr. Theena elMadej, built on the ruins of a former lunar base destroyed by "the Pulse" in 2265. The Discovery Center was intended as a showcase for Mestiko's scientific achievements, and a symbol of its self-sufficiency and ability to become an equal partner among its interstellar neighbors.
In 2291, the Discovery Center was attacked by the Torye, with the assistance of Dr. Theena. Nineteen were killed, and a prototype subspace-disruption weapon was stolen. This created a scandal, leading to questions of how the Discovery Center was operated and funded, and of whether its operation should continue. (TOS eBook: Mere Anarchy: The Blood-Dimmed Tide)