The ViaSat-3 Americas satellite has completed its Final Integrated Satellite Test (FIST) and has now advanced to the Flight Final phase of integration, where it is undergoing final build-up for its flight configuration, according to the satellite communications provider Viasat.   The satellite had previously passed mechanical environmental testing and thermal vacuum testing, which replicated vacuum and extreme heat and cold temperatures in orbit, where the satellite is projected to operate for the next 15 years.   FIST is intended to test all of the satellite’s payload and bus systems to ensure they perform correctly after the pressures of mechanical environmental testing, which simulates the spacecraft’s launch. Following the mechanical and thermal strains of the previous test phases, FIST confirmed that the satellite continued to function as intended.   The Ka-band satellites of the ViaSat-3 class are anticipated to offer the finest bandwidth economics in the sector with significant flexibility…