GPS II-3 (USA-42)

GPS II (Global Positioning System) or Navstar II (Navigation System using Timing And Ranging) are improved satellites of the second generation of the GPS navigation system. The Block II satellites were the first full-scale operational GPS satellites. They were designed to provide 14 days of operation without contact from the control segment. Rockwell was the prime contractor, building a single Block 2 SVN 12 qualification vehicle under a 1981 amendment to the Block I contract. In 1983 Rockwell was awarded a contract to build 28 Block II/IIA satellites.