WASHINGTON — The U.S. Air Force launched the seventh of its GPS 2F series of positioning, navigation and timing satellites Aug. 1.
The launch was aboard a United Launch Alliance Atlas 5 rocket from Cape Canaveral Air Force Station in Florida. Liftoff occurred at about 11:23 p.m. Eastern time.
The Air Force now has 14 of the Russian-built RD-180 engines that power the Atlas 5 first stage remaining in the country. Future availability of that engine has come into question amid a deterioration of Russia-U.S. relations.
The launch was ULA’s second successful mission in four days. The previous mission, aboard a Delta 4 rocket, placed three space surveillance satellites into orbit.
The GPS 2F satellites, built by Boeing Space and Intelligence Systems of El Segundo, California, provide better accuracy and resistance to jamming than the previous generation of GPS satellites, most of which are still in operation. The launch helps bolster a GPS fleet whose satellites are beginning to show their age, Air Force officials say.
The new satellite will be one of 31 active satellites in the constellation. Once GPS 2F-7 checks out on orbit, the Air Force plans to move one of its older GPS 2A satellites into a reserve mode, said Col. Bill Cooley, head of the GPS directorate at Air Force Space and Missile Systems Center in Los Angeles.
The GPS 2A satellites had a life expectancy of 7.5 years. The satellite to be placed in reserve mode is 22 years old, Cooley said.
Cooley described the launch as part of “the most aggressive launch campaign schedule” for the GPS program since 1993.
“Our robust launch tempo requires vigilance and attention to detail, and mission success is our top priority,” Craig Cooning, president of Boeing Network & Space Systems, said in an Aug. 2 press release. “We continue to partner with the Air Force and ULA to effectively execute the launch schedule.”
The Air Force has taken a series of steps in recent years to extend the life of the on-orbit GPS satellites, including changing the way it charges the batteries on some satellites.
The Air Force expects to launch one more GPS 2F satellite before the end of the year, three in 2015 and the last of the series in 2016. The next-generation GPS 3 series of satellites are slated to start launching in 2016.