SpaceX finished its 21st and final launch of 2018 by launching the most recent GPS satellite of US Air Force on December 23. The launch took place at Cape Canaveral in Florida at 8.51a.m. Eastern. The launch was supposed to take place 5 days earlier but weather and tech issues caused a delay. The first GPS 3 satellite, the Lockheed Martin payload, separated from the Falcon 9 rocket 1hr 59mins after launch, marking two new milestones for SpaceX. As compared to 18 launches in 2017, the company made 21 launches this year. It also completed its first defense mission through Evolved Expendable Launch Vehicle program of US Air Force.
Initially SpaceX had predicted 30-40 launches, which it fell short of. But nonetheless, it managed to launch a Falcon Heavy for the first time. Also, its launch rates have increased significantly from 6 and 8 in 2015 and 2016 respectively to the current count. Other national security missions have been launched by SpaceX in 2017 such as NROL-76 of National Reconnaissance Office, uncrewedX-37B of Air Force. 4 other GPS 3 satellites are meant to be launched in addition to the mission that took place today. The satellite, a replacement for a GPS 2R spacecraft that was launched in 1997, after being boosted into a highly elliptical orbit, will enter a medium Earth orbit and join US GPS constellation of 31 previously-launched satellites. It will deliver timing services, navigation and positioning to over 4 billion people. The GPS 3 satellite was launched after a 4-year-delay from its original schedule.
A stronger signal is broadcasted to counter electronic jamming by GPS 3 satellites. It’ll broadcast 4 civic signals and launch and control checkout, which could take 6-9 months, with OCX Block o, new ground control system of Air Force. On orbit checkout will happen around 10days after launch. On being declared operational, the satellite will undergo further 6-9 months of testing for integration into constellation. 18 of 31 GPS satellites have been manufactured by Lockheed Martin. The new GPS 3 satellite, nicknamed ‘Vespucci’, costs about $529m and the second GPS 3 satellite will likely be launched in 2019. These satellites are expected to be functional for at least 15years.