Lockheed Martin has delivered the eighth and final satellite in the modernized Global Positioning System Block IIR (GPS IIR-M) production to the U.S. Air Force. The GPS constellation provides situational awareness and precision weapon guidance for the military. The worldwide system also supports a range of civil, scientific and commercial functions – from air traffic control to the Internet — with precision location and timing information.
Currently, three IIR-M spacecraft are in orbit, along with 12 original Block IIR satellites within the overall 30-spacecraft GPS constellation. Each satellite in the Block IIR-M series includes a modernized antenna panel that provides increased signal power to receivers on the ground — two new military signals for improved accuracy, enhanced encryption and anti-jamming capabilities for the military — and a second civil signal that will provide users with an open access signal on a different frequency.
Based on the navigation user range error, which measures GPS accuracy, the Block IIR satellites enable suitably equipped users to determine precise time and velocity as well as worldwide latitude, longitude and altitude to within one meter.
The final eight spacecraft, designated Block IIR-M, were modernized to enhance operations and navigation signal performance for military and civilian GPS users around the globe. The company is also responsible for launch and flight operations support of the GPS IIR and IIR-M satellites.
The third GPS IIR-M spacecraft was launched successfully on Nov. 17, 2006 by Air Force Space Command's 2nd Space Operations Squadron (2 SOPS) at Schriever Air Force Base, Colo., which manages and operates the GPS constellation for both civil and military users. Whereas the fourth GPS Block IIR-M satellite was delivered to Cape Canaveral to support a late 2007 launch.
