GPS IIF-5 Successfully Launched

GPS IIF-5 Successfully Launched

GPS IIF-5 successfully launched on February 20th after a short delay due to solar radiation patterns. The launch was completed at Cape Canaveral under U.S. Air Force command, putting the fifth satellite in the new array in place and receiving preliminary signals within three hours of on-orbit activation. The new addition promises improved tracking accuracy and timing through improvements in atomic technology, and the craft has a long life design expected to keep it in service for the next 12 years. Firing into space at 8:59 eastern time, just at the end of its launch window, on the nose of a United Launch Alliance Delta IV rocket, the Boeing made satellite was placed in its assigned orbit after a brief elliptical arc. GPS IIF-5 will replace an ageing piece of the global positioning network known as GPS IIA-28, the last part of a series launched in 1997. GPS IIA-28 will take on a reserve role until it is no longer useful, at which point it will be vaporized in the atmosphere.

The first GPS satellite was launched by Boeing in 1978, and as satellites age they must be replaced in a timely manner to maintain the minimum number needed to ensure global coverage. While some satellite are in a geosynchronous orbit, meaning they hover over one place on Earth, many orbit the globe resulting in differing areas of coverage. The problem of losing coverage is solved by satellites communicating with each other as they orbit in a pattern that results in each area being covered by the next orbiter just as the last one moves on. The U.S. Air Force has over 40 orbiting craft in the atmosphere that have racked up over 500 years of combined service time to ensure that no coverage areas are kept to the absolute minimum. The system requires careful planning and timing, something that GPS IIF-5 will bring in abundance. Now that GPS IIF-5 has successfully launched the system will be better equipped to help users of commercial, military, and private natures with more refined instruments, higher signal strength, and enhanced anti-jam capabilities. On top of this, new dual frequency GPS locators will benefit from the IIF-5’s third civil signal and second civil signal transponders. More resilient signals allow for improved bandwidth and enhanced security of data transfer.

This was the first launch of 2014 for the IIF series. The first four were launched between 2010 and 2013, with the next planned to go up in the second quarter of this year. There are six more orbiters in the series being held at the Boeing Satellite Development Center in El Segundo California, set to be launched by Evolved Expendable Launch Vehicles. Once they are in orbit the satellites come under control of the U.S. Air Force. After GPS IIF-5 successfully launched, Launch Decision Authority Col. Douglas Schiess said “Once again, a group of talented mission partners rose to the challenge of launching another successful mission from the Cape.” He went on to say that he was pleased with the results and praised the work and skill of all partners involved.

By Daniel O’Brien


Aerospace Manufacture and Design
U.S. Air Force
GPS World