GPS Block III on Hold

Since GPS achieved Fully Operational Capability on July 17, 1995, GPS has become an essential navigational tool for civilians and military alike. Keeping the system up-to-date has proved to be a problem. Originally the system was supposed to be up and running in February of 2016 but has been delayed at least until 2023.
The latest iteration of the GPS satellite array is called GPS Block III. These satellites must be launched (and will greatly increase navigational accuracy) in order to keep the Navstar global positioning system operational.
The satellites have already been built by Lockheed-Martin and consist of ten new, advanced satellites to be launched into orbit by SpaceX Falcon rockets. The hold up is the U.S. government wanting to make sure the hardware actually gets up there as they independently seek to confirm the safety and reliability of the SpaceX rocket systems.
The new GPS satellites will boost additional easier to track signals for civilian navigational uses and a Military code (M-1) providing anti-jamming security use for the military.

Will an alien invasion by secular and militaristic extraterrestrials solve a lot of problems on Earth?

An alien invasion by secular and militaristic extraterrestrials would solve one of the biggest problems we have here on Earth. That problem being: does life exist on other planets? Finally we would have an answer!

How will space be used for military purposes in the future?

It already is being used for military purposes right now as in spy satellites. Even very recently SpaceX was tasked to launch a U.S. spy satellite into orbit but it exploded and the satellite didn’t make it.

In 1984 a Titan 34D rocket launched the KH-9 and KH-11 satellites for “reconnaissance,” and the DSP-2-6R satellite for missile detection. The list just starts there and goes into the hundreds including many intelligence-gathering satellites and so on.

And, by the way, not just by the United States, but other governments as well.

Furthermore, the Chinese government once shot a missile to destroy their own satellite in space just to say the could, and they succeeded, vastly increasing the dangerous debris cloud floating now in orbit. It was a military demonstration.

Edit addendum: The government of India has recently done the same foolish thing – shot down a satellite to prove they could do it – increasing the amount of space junk exponentially.