“As a result, extensive and more operationally relevant testing with actual GPS satellites, ground antennas, and user equipment led to an increase in finding extensive system issues across all subsystems, many of which have not been resolved,” Ainsworth told the House Subcommittee on Strategic Forces in prepared testimony.

“For over 15 years, the program has experienced significant technical challenges, schedule slips, and associated cost growth, putting at risk the launch and capability of future GPS satellites,” Ainsworth continued.

Delays in the OCX program forced the military to retool the GPS network’s decades-old legacy control system to manage the GPS III satellites. Upgrades in 2020 allowed the Space Force to begin using a subset of the new capabilities enabled by “M-code” GPS signals designed for warfare.

The military-grade signals are especially important now to combat GPS jamming and spoofing around war zones in Ukraine and the Middle East. M-code is more resistant to jamming, and its encryption makes it more difficult to spoof, a kind of attack that makes receivers trust fake navigation signals over real ones. The upgrade also allows the military to deny an adversary access to GPS during conflict, while maintaining the ability for US and allied forces to use M-code for an advantage.

Military officials previously thought they needed OCX up and running to fully exploit M-code signals on approximately 700 types of weapons systems such as airplanes, ships, ground vehicles, and missiles.

Because of its civilian and military importance, the GPS network is an “attractive target for adversaries,” said Lt. Gen. Doug Schiess, the Space Force’s deputy chief of operations. “Jamming (denial of signal) and spoofing (false signals) are a current and growing threat to GPS. We are modernizing GPS to mitigate these threats.”