As reported by The Verge SpaceX has asked the FCC whether it can launch 1,584 satellites on 550 kilometers, in contrast to the originally proposed orbit of 1,110 kilometers. It argues that the lower orbit can enable it to reduce the number of satellites required for the operation and, above all, to support the disposal of these satellites when they are no longer operational. While SpaceX plans to desorb its satellites actively when a satellite goes down and SpaceX can not desorb the satellite as planned, the lower orbit may help the company dispose of this satellite in a timely manner. At such a low orbit, natural effects such as gravity and particles in the atmosphere that push satellites down over time will cause them to be removed from orbit within five years, if not earlier.
That's important, especially as SpaceX is supposed to launch 1
In its new FCC application, SpaceX said its two test satellites had shown what "lower altitude operation" offers. The FCC still has to approve the revised plans.