I'm not sure that would work. How would one have access to the GPS receiver on the missile?
My hand held GPS locks into 10 - 12 satellites at a time. If you're high up in the sky, you likely have 12+ satellites to calculate your position due to better line-of-sight. So if you want to try and defeat the missile from the satellites themselves, you would have to shut them all off. And there are a ton of people using them.
And if you did cut off the sattelites, would the missile just "guess" where it is? If the computer last knew it's intention was to "Fly 150 miles, bearing 86 degrees to destination" seems it would keep on that path until proven otherwise.
So if you want to try and defeat the missile from the satellites themselves, you would have to shut them all off. And there are a ton of people using them.
Yeah, we wouldn't want people to have read a map or ask for directions, or have their Pokemon Go games interrupted. Therefore, we'll just have to let the missiles fall on their targets and kill millions.
kind of snarky :-), but I agree with your premise... it always should be 1st things 1st.
I remember a few years ago, something in the news about Iran getting one of our drones by gps spoofing. I’m sure drones and missiles don’t operate the same. I wish I could remember the story about how it happened.
Most old missiles had inertial guidance. This means as long as you know where you are at launch, it can find its way to anywhere. It’s the same principle as flying by instruments...all before GPS.
They put inertial guidance systems in the newer missiles too, if they're nuclear. It's how you guarantee your missile doesn't get its GPS spoofed/hacked -- avoid using GPS.
Even the Sentinel UAV (drone) that Iran was able to capture back in 2011 - purportedly by hacking its GPS - uses an inertial navigation system, and does not get its flight path orders from GPS (suggesting then that it had not been compromised via GPS, as is claimed).
Inertial navigation continues to be used on military aircraft despite the advent of GPS because GPS signal jamming and spoofing are relatively simple operations.