USSF-50 (NGG-2)

Second of two Next Generation GEO (NGG), also known as Next Generation Overhead Persistent Infrared (NG-OPIR), geostationary satellites geostationary satellites designed to deliver improved strategic missile warning capabilities that are more survivable against emerging threats. They will replace the current Space-Based Infrared System satellites. Two additional satellites will operate in highly elliptical polar orbit.