Each probe can pick up GPS signals and signals from eLoran, an enhanced version of Loran, the ground-based terrestrial radio-navigation system first used by the American and British navies during the second world war.

ECONOMIST: GPS jamming

This digital elevation model (DEM) will be put to myriad uses - everything from improving the safety of aircraft navigation to understanding better which areas of ground are most at risk during a flood.

BBC: German radar satellites fly tight space waltz

Honeywell executives, who haven't previously discussed the project publicly, say the system uses onboard computers and navigation devices to automatically control aircraft movements on the ground.

WSJ: Honeywell Tests Autopilots for the Tarmac

The batteries are not essential during flight as they are mainly used on the ground during maintenance activity, Sinnett said, such as providing navigation lights and braking while the airplane is towed.

CNN: Boeing announces changes to Dreamliner battery system

The U.S. military has become heavily dependent on orbital systems and their supporting ground networks to connect far-flung forces, collect vital intelligence, detect missile launches, provide precise navigation information, and monitor weather conditions.

FORBES: Lessons For Obama In Clinton's Near-Destruction Of The Military Space Program