The Navy Precision Optical Interferometer (NPOI) is a major astronomical interferometer, with the world's largest baselines, operated by the Naval Observatory Flagstaff Station (NOFS) in collaboration with the Naval Research Laboratory (NRL) and Lowell Observatory. The NPOI primarily produces space imagery and astrometry, the latter a major component required for the safe position, navigation, and orienting of the world's orbiting satellites through upwards of 19,000+ pieces of orbiting space debris. The facility is located at Lowell's Anderson Mesa Station on Anderson Mesa about 25 kilometers (16 mi) southeast of Flagstaff, Arizona (USA). Until November 2011, the facility was known as the Navy Prototype Optical Interferometer (NPOI). Subsequently the instrument was temporarily renamed the