MIT Lincoln Laboratory serves as the scientific advisor to the U.S. Army's Reagan Test Site, on the Kwajalein Atoll in the Marshall Islands approximately 2,300 miles west southwest of Hawaii. A resident team of Laboratory staff operate the four radars and conduct upgrades to the sensors and command-and-control infrastructure. About 20 Laboratory personnel are stationed on Kwajalein Atoll at any given time, serving two- to three-year tours before returning to the Laboratory. The Reagan Test Site is a world-class range and test facility for technologies involved in ballistic missile defense and space surveillance.