A newly certified Global Positioning System (GPS) range tracking system, developed for the Minuteman III Intercontinental Ballistic Missile (ICBM) by Northrop Grumman Corp., was successfully flown at Vandenberg Air Force Base for the first time, as one of the two independent tracking systems required for range safety.


The GPS Metric Tracking System (GMTS) was developed, tested and provided by Northrop Grumman’s Mission Systems sector as part of its role as the US AiR Forces’ ICBM prime integrating contractor.

“This new system will greatly improve capabilities for range users through more precise tracking, fewer range delays caused by radar downtime and significantly reduced launch support costs,” said John Clay, vice president and general manager of the Northrop Grumman ICBM Prime Contract.

The GMTS replaces the C-band transponders previously used to track the Minuteman III test launches from Vandenberg Air Force Base. As directed by the Air Force Space Command, the C-band tracking system is to be deactivated in FY 2007 for cost saving and modernization.

The C-band tracking radars use the on-board C-band transponder signal to lock onto the missile and track missile position and velocity. The GMTS now utilizes the GPS satellite constellation to ensure accurate tracking worldwide. The Minuteman III incorporates GPS translators on the missile to receive information from the satellites and relay translated time and identification data to ground facilities.

This data is used to more accurately calculate the position and velocity of the missile, which is required for range safety tracking during missile flight. Northrop Grumman is the Air Force’s ICBM prime integration contractor charged with modernizing and maintaining alert readiness of the US ICBM weapon system through 2020. The company manages a team consisting of three principal teammates—Boeing, Lockheed Martin and ATK—and more than 20 subcontractors.