11th GPS satellite – BLOCK IIF-11 (SV-12) is going to be launched atop of Atlas V 401 rocket from Cape Canaveral.
On 30th October 2015 from Cape Canaveral launch site SLC-41 will be launched penultimate GPS satellite under contract signed between U.S. Air Force and Boeing in 1996. As far as Air Force reduced number of satellite from Block IIF series to twelve (assuming thirty satellites at the beginning) Boeing closes to the end their participation in GPS program. It seems that after thirty four years of its domination since first contract signed in 1974, its position as a U.S. defense contractor weakens. Contracts for GPSIII satellites were signed with Lockheed Martin in 2008 (worth $1.4 billion) and in 2012 (worth $68 million) and are reaching to start point – 4th May 2015 first GPSIII satellite was rolled out for testing in Lockheed Martin facility in Denver.
Block IIF satellites are medium earth orbit operating on altitude of approximately 20,460 km. Orbit life is 12 years (Block IIA were designed for 7.5 year), weight 1630 kg, first launch of satellite from this generation was in 2010. It was one of the reasons of delay in contracted launches – last satellite from Boeing contract was originally scheduled for 2006. In spite of longer orbit life, Block IIF has not installed Selective Availability system which was implemented to reduce civilian receiver accuracy. This generation has also improved accuracy and better jamming resistance.
Atlas V is not necessary most often used rocket during GPS missions. United Launch Alliance trusts in their flagship rocket and since 2013 uses Atlas instead Delta. For this mission is planned use of Atlas V from 400 series. Its prime feature is 4 m in diameter and almost 13 m in length payload space. RD-180 engines designed in Energomash in Russia are fueled with oxygen and kerosene and produce 390226 kg thrust, eventually supported by solid fuel boosters (Aerojet Rocketdyne RL10A-4-2). Combined with single-engine upper stage Centaur should provide placing satellite direct into operational orbit. Ironically, one of the Boeing’s last GPS satellites will be launched with rocket created by its main competitor – Lockheed Martin.