GPS Alternative Eyed for SDA’s Tranche 2 Transport Layer

The Proliferated Warfighter Space Architecture Tranche 2, scheduled for launch in 2026, is key to a global positioning system alternative that the Space Development Agency is working on with the U.S. Army, SDA Director Derek Tournear said. He noted in the National Security Space Association’s online SpaceTime Series on Dec. 7 that the Army has been pioneering non-GPS-dependent positioning, navigation and timing capabilities across the Department of Defense.

The DOD mostly depends on GPS for PNT data, but because of the system’s vulnerabilities, military services have been seeking other technologies for use in locations inaccessible to GPS or with disruptions in access, Federal News Network reported.

In the interim of the Trance 2 launch, Tournear disclosed that the SDA will start integrating a navigation message into the Link-16 payloads of its low-Earth orbit data relay satellites.  

He noted that the military has been using Link 16 since the 1980s, before GPS use in combat became mainstream. While Tournear admitted that Link 16 is “not nearly as good as GPS,” he also noted that it is still a viable alternative for PNT purposes by simply “timing transfer between the satellites.”