The space station in Star Trek II that houses the Genesis device is Regula I.
Regula I is a Federation research station where Dr. Carol Marcus and her scientific team develop the Genesis Device. The device is designed to reorganize lifeless matter and transform a barren world into a habitable environment. Carol’s son, David Marcus, is also part of the Genesis project.
The station becomes the first major target of Khan Noonien Singh after the USS Reliant discovers the project. Khan captures Reliant and attacks Regula I, killing members of the research team while searching for the Genesis technology. Kirk later travels there after Enterprise receives the station’s distress call.
Regula I is often confused with the nearby Regula planetoid. The station is the laboratory and initial storage site; the planetoid contains the hidden Genesis cave where Carol, David, and Kirk’s party later encounter the device. It is also not Earth Spacedock, Deep Space Station K-7, or Starbase 74—those names belong to other locations in Star Trek continuity.