On March 25, 2015, United Launch Alliance (ULA) conducted successful launch of its Delta IV Medium+ (4,2) launch vehicle with GPS IIF-9 navigation satellite into a semi-synchronous circular orbit from Space Launch Complex 37 (SLC-37) at Cape Canaveral Air Force Station, Florida.
GPS IIF-9 mission has marked the 29th Delta IV launch and the 69th orbited GPS satellite. This is also ULA's fourth launch in 2015 and the 95th successful launch since the company was formed in December 2006.
GPS Block IIF, or GPS IIF, is an interim class of GPS satellites, which will be used to keep the Global Positioning System operational until the GPS Block IIIA satellites become operational. They are being built by Boeing under the contract for a total of twelve Block IIF satellites. The spacecraft have a mass of 1,630 kilograms and a design life of 12 years.
“Congratulations to the Air Force and all of our mission partners on today’s successful launch of GPS IIF-9! The ULA team is privileged to work with this world-class US government and contractor mission team, and we are proud to contribute to the GPS capabilities that were delivered to orbit today.” Jim Sponnick, ULA vice president, Atlas and Delta Programs
Global Positioning System utilizes 24 satellites, in six different planes, with a minimum of four satellites per plane. The satellites continuously transmit digital radio signals pertaining to the exact time (using atomic clocks) and exact location of the satellites. With the proper equipment, users can receive these signals to calculate time, location, and velocity. The signals are so accurate that time can be measured to within a millionth of a second, velocity within a fraction of a mile per hour, and location to within feet. Receivers have been developed for both military and civil purposes for use in aircraft, ships, land vehicles, and to hand carry.
ULA's next launch is the Atlas V AFSPC-5 mission for the United States Air Force, scheduled for May 6 from Space Launch Complex-41 from Cape Canaveral Air Force Station, Florida.