Over a Year on Orbit with Two Lightning Mappers: Lessons Learned

After more than a year of operational experience with two Geostationary Lightning Mappers (GLM) on the GOES-16 and GOES-17 satellites, we describe the highlights from a large and growing data archive of lightning observations from space. We contemplate lessons learned from the GLM program, covering items that we re-confirmed, items that we resolved but wish we had anticipated better, and items that surprised us. We conclude with a look at what the future may hold for space-based optical lightning mapping around the globe.