A New Satellite in the GPS Constellation

After a week of delays caused by everything from technical malfunctions to bad weather, the first in a series of GPS IIF satellites was finally launched from Cape Canaveral late in the evening on May 27, 2010. A total of twelve IIF satellites are expected to launch through 2014, with the next launch tentatively scheduled for November 2010.

The IIF satellites are part of the ongoing modernization of the GPS constellation by the United States Air Force. The IIFs have improved atomic clocks used for timing and are therefore expected to provide more accurate navigation signals than those currently available from the rest of the GPS constellation. The IIFs will also broadcast the civil L5 signal for safety-of-life applications, which has the potential to enhance indoor reception with its wider bandwidth and lower frequency. The new satellites will also be compatible with the Galileo, GLONASS and QZSS constellations. In addition, the IIFs will assist the IIRM series already in orbit with military-specific M-code, a unique encryption for military users requiring secure access.

The new satellite, officially known as GPS IIF-1 SV-1, is expected to begin broadcasting its signal to GPS users following a three- to four-month testing period. In addition to being the first in the new IIF satellite series, this launch was significant for another reason as well. GPS IIF 1 SV-1 was carried into orbit on a Delta IV rocket, making it the first GPS satellite since 1985 that was not placed in orbit by an Atlas rocket.