GPS III ‘Magellan’ Starts Signal Transmission
The first GPS III satellite, “Vespucci,” was launched in December 2018, started signal transmission in January 2020, and was set healthy later that month. The second GPS III satellite, nicknamed “Magellan,” was launched on Aug. 22, 2019, on a Delta IV rocket from Cape Canaveral, Florida.
Magellan, also identified by its space vehicle number (SVN) 75 (here referred to as GPS-75), started signal transmission with standard pseudorandom noise code (PRN) number 18 (here referred to as G18) on March 13. The L1 C/A, L1 P(Y), and L2 P(Y) signals were activated at 17:16:30 GPS Time (GPST), while the L1C, L2C and L5 signals followed less than two hours after Vespucci’s launch at 18:59:30 GPST. Transmission of navigation messages started at 19:00:00 GPST with GPS-75 (G18) marked as unhealthy.
Read more in GPS World article. https://www.gpsworld.com/gps-iii-magellan-starts-signal-transmission/