Millstone Hill Radar

The Millstone Hill Radar (MHR) is an early warning and tracking radar located at Millstone Hill in Westford, Massachusetts. Initially constructed in 1956 as a prototype for the Ballistic Missile Early Warning System (BMEWS) and operating at 440.2 MHz in the UHF band with a 5 MW peak power, it featured an 84-foot diameter antenna. This system served as a development model for RCA's AN/FPS-49, AN/FPS-49A, and AN/FPS-92 radars, and notably detected the Sputnik I satellite on October 5, 1957. In 1965, the MHR was reconfigured to operate in the L-band with a new transmitter and an 84-foot antenna featuring a 12-horn monopulse feed, contributing to the Space Surveillance Network (SSN) for both near- and deep-space surveillance. The MHR is operated by the MIT Haystack Observatory Atmospheric Sciences Group and should not be confused with the Millstone Hill Incoherent Scatter Radar (MHR ISR) at the same site.

radartutorial.eu: https://www.radartutorial.eu/19.kartei/01.oth/karte043.en.html