Yeah, that's certainly a good point. The analogy with cars is a bit tricky though as we have well defined rules that help us pack them very closely together on

Yeah, that's certainly a good point. The analogy with cars is a bit tricky though as we have well defined rules that help us pack them very closely together on the surface. For example: roads, lanes, controlled intersections. Those things aren't quite the same when talking about orbits because cars and satellites aren't spread out the same way. The other commenter made the point about some safety margin, which obviously has to be a part of the equation. The speed and error of orbits would play into whatever that number comes out to be. Regardless of there being lots of space, there's still some limit, even if it's 1,000 constellations. Some variables I don't quite know: 1. Acceptable altitude range for constellations 2. Typical positioning error of a satellite 3. Average failure rate and failure mode of a satellite - ex. does a dead satellite automatically deorbit itself or do we need to wait for the orbit to decay? I'd imagine decay at that altitude is fairly quick. Would a decaying satellite in a higher orbit need to be accounted for? 4. Required satellite density in orbit and the number of unique orbits, their arrangement, etc. I'm sure there are other factors, too...