Medical Facility Endurance
From Halopedia, the Halo wiki
The unnamed ONI Medical Facility was one of many stations that orbited the UNSC Military Complex known as Reach. The ONI medical facility was where many classified experiments and projects were conducted. In 2525, the Spartan II soldiers underwent their enhancement surgeries and upgrades on this station. Dr. Catherine Halsey and Chief Petty Officer Franklin Mendez oversaw the surgeries. Some 30 of the Spartans died during these surgeries.
This station was likely destroyed when Reach fell to the Covenant during the Battle of Reach in 2552.