Gralafi was a class M planetoid located somewhere in the space of the galaxy's Alpha or Beta Quadrants, in orbit of the Kondaii star system, eight hundred thousand kilometers from the planet Dolysia. It was the location of a Dolysian colony.
History and specifics
Gralafi was rich in erinadium deposits.
Thousands of years ago, Gralafi was home to a Kalandan outpost which was used as a repository of their knowledge. They created an energy field to shield the planet which automatically opened for a short period once every three years. It continued to do so even after the Kalandans became extinct.
By the 23rd century, the Dolysians had established a mining colony on Gralafi. In the year 2269, the Federation science vessel USS Huang Zhong was assigned to study the energy field surrounding the planet, but accidentally triggered the outpost's defense system, causing the ship to crash and killing most of the crew. The USS Enterprise, which had been assigned to assist the Huang Zhong arrived to recover the wreckage and find out what happened. They discovered the Kalandan outpost, but their investigations were complicated by the arrival of the Romulan bird-of-prey ChR Nevathu, which triggered a self-destruct sequence. After the Romulans were defeated, the self-destruct was aborted and the energy field was disabled, allowing free movement between Dolysia and Gralafi. (TOS novel: That Which Divides)