Several Low-Earth-Orbit (LEO) networks were proposed, but only one got off the ground: the Iridium system. The original Iridium proposal called for a "constellation" of 77 satellites, which gave the plan its name: the element iridium has atomic number 77, meaning that an iridium atom has 77 orbiting electrons. Before the satellites were launched, the constellation was scaled back to 66 active satellites, but no one wanted to change the name to Dysprosium.
A NASA astronaut, forced to retire years earlier so he could save his family farm, has never given up his dream of space travel and looks to build his own rocket, despite the government's threats to stop him.
A Fermi estimate is a quick-and-dirty solution to an arbitrary scientific or engineering analysis problem. Fermi estimation uses widely known numbers, readily observable phenomenology, basic physics equations, and a bunch of approximation techniques to arrive at rough answers that tend to be correct within an order of magnitude or so. The term is named for Enrico Fermi, who was famously good at this sort of thing.
…It struck me that there is counterpart to this kind of thinking on the synthesis side, where you use similar techniques to arrive at a very rough design for a complex engineered artifact. I call such a design approach Dyson design, after the physicist Freeman Dyson, who was one of the best practitioners of it (not to be confused with inventor James Dyson, whose designs, ironically, are not Dyson designs).