Originally Posted by 250kts
Cant comment on whether the US forgot to send up replacements, but certainly NO threat to GPS.
As the vast majority of both civil and military flights are using this as there primary navigation tool now, I cannot see this being allowed to happen. Would make for very interesting times trying to keep them apart! Mind you it would make the job more interesting whilst the traffic has dropped so much .........
As an aside, whilst GPS may play a part in aircraft navigation systems, it doesn't have role in keeping them apart - this is done by ATC using primary and secondary radars, Mode S and various other little gizmos. It doesn't rely at all on the aircraft being able to tell ATC where it is, ATC already knows that, especially as GPS is two dimensional.