They are radically different from what has been the standard for almost the entire history of humans hurling things into orbit. They tantalize potential customers—including governments, businesses and consumers—with the promise of fast, always-on internet access, anywhere on Earth, anytime. Thousands of this new kind of satellite are already operational, most of them powering the Starlink satellite network from Elon Musk’s SpaceX, which counts more than two million customers in 60 countries around the world, including Ukraine, where it has been critical to that country’s war with Russia, and Iran, where the network is helping citizens get around that country’s...