Sierra Space completes ground demo of navigation satellite for U.S. Space Force program
An artist's depiction of a GPS satellite on orbit. (Lockheed Martin) By Sandra Erwin, Published by Space News, 8 May 2025 WASHINGTON — Sierra Space announced May 8 it has completed a ground-based demonstration of a navigation satellite prototype for the U.S. Space Force’s Resilient Global Positioning System (R-GPS) initiative,