SpaceX launched a joint NASA-European environmental research satellite early Monday, the second in an ongoing billion-dollar project to measure long-term changes in sea level, a key indicator of climate change .  The first satellite, known as Sentinel-6 and named in honor of NASA climate researcher Michael Freilich, was launched in November 2020 . The latest spacecraft, Sentinel-6B, was launched from California atop a Falcon 9 rocket at 12:21 a.m. EST. Both satellites are equipped with a