The first GPS III satellite has taken its place in the celestial sphere, initiating an upgrade of the Global Positioning System that promises faster, more reliable service and hardened protections against jamming and cyber attacks for lower costs than the current constellation. But the Air Force, which launched GPS III on Dec. 23, 2018, has a long, uncertain way to go before delivering on a project that has seen significant delays and cost overruns involving both space and ground operations. […]