Roger writes:

I wonder what this has done to the risk for our GPS constellation?

The collision was last year. GPS satellites are in orbits thousands of miles
higher than those of the Iridium and Kosmos satellites that collided.

The major risk of GPS is not satellite loss, but spoofing and jamming and
temporary signal loss due to natural phenomena.

It amazes me that the President was stupid enough to approve the
decommissioning of LORAN, since it worked well and provided a viable back-up
system to GPS.

Many people are rushing headlong towards a GPS-only navigation system that
will be crippled if anything happens to GPS (and sooner or later, something
will).

The current situation with volcanic ash in Europe stopping airline flights is
a good example of what happens when you have no contingency plans at all. GPS
for aviation is moving in that same direction.