Two Satnav Satellites Lost Within 10 Days
The first geostationary satellite for India’s Gagan GPS space-based augmentation system (SBAS)–essentially similar to Waas–was lost on April 15 when its launch rocket’s second-stage cryogenic engine failed to ignite. That followed the early-April loss of Intelsat’s Galaxy 15 geosat, which was carrying the FAA’s Pacific Waas transponder. The satellite was slowly drifting out of orbit and could no longer provide usable GPS accuracy corrections. The FAA is reviewing reversion to the Inmarsat Pacific geosat used previously to provide Waas coverage over the western U.S. or, alternatively, accelerating the schedule for its planned third Waas geosat launch. Re-introducing the Inmarsat satellite would take about one year, while the time frame to launch the planned third Waas satellite was not stated, but would be longer. Although now a single-thread system, Waas LPV coverage will continue unchanged, except for western Alaska, which will lose most service.