The Space Force announced this week the four companies that will compete to build its first batch of Resilient GPS satellites, aimed at ensuring military and civilian users have access to reliable positioning, navigation, and timing signals. The service’s acquisition arm, Space Systems Command, chose L3Harris, Astranis, Axient, and Sierra Space to create design concepts for the program. The Pentagon has become increasingly concerned about GPS signals being jammed or spoofed by adversaries, with Russia taking advantage of this vulnerability in Ukraine. The Resilient GPS program, or R-GPS, is meant to augment the Space Force’s current constellation of GPS satellites with a fleet of smaller spacecraft that will transmit a set of signals widely used by the military and civilian agencies. The early funding has allowed Space Systems Command to conduct market research, host an industry day, release a solicitation, and award the first round of contracts in less than six months. The House Appropriations defense subcommittee has cast doubt on whether the effort will be as resilient as the Space Force hopes, questioning the use of quick-start authorities for the program.