Today the GPS satellite SVN32 will be set to unhealty. There is a news on the web discussing the fact that such a decision could be related to the fact that the control segment of GPS could have issues in managing 32 satellites (since February 26, the SVN23 broadcasting PRN32 was set to healty).
I believe this is probably a matter of some trivial issues related to numbering and size of registers s and not certainly due to the capability of the US to manage 32 satellites. Nevertheless, it makes me wonder how difficult it is to design systems that are expected to last for several years, and how it must be done with a good forecasting not only of the market but also of the technology for the years to come...
And I also wonder if Galileo design is looking forward to the upgreadability of the signals and of the system in order to cope with the evolutions that would keep it at the leading edge.