Billions of people around the globe utilize GPS as a part of their day to day lives, but few people realize that the satellite infrastructure that provides that method of tracking and navigation was put into orbit and is continuously maintained by the United States military.

With the exception of the Roscosmos GLONASS network launched by the Russians that sees little use outside of the Russian military, America’s constellation of only 31 “GPS 2” satellites provides the coverage necessary for the global use of the infrastructure. China is, however, currently developing plans to launch their own GPS constellation sometime in the future.

With both China and Russia developing new methods to deny access to the GPS network in target areas, the U.S. military has recently adopted a two-fold approach to the possibility of conflict with a peer or near-peer nation capable of using such network denial methodologies. Last month, the U.S. Air Force conducted large scale combat training operations without the use of the GPS network, approximating what warfare might be like without the system so much of the American military has come to rely on. This training strategy accounts for the first of the two approaches to managing a foreign nation’s ability to block America’s access to its GPS satellites.

The second approach, as outlined in a request for proposal released on Feb. 13, is to launch an entirely new constellation of advanced GPS satellites designed specifically to counter such attacks.