The next GPS payload will be fully digital

By: Nathan Strout

The navigation payload for the next iteration of GPS satellites has passed its critical design review, contractor L3Harris announced Feb. 11.

According to the company, which is designing and building the system, the new payload will provide a more powerful, reliable and flexible GPS signal than previous satellites.The GPS IIIF satellites will follow the first 10 GPS III satellites—the first of which is already on orbit and operational. The Air Force plans to eventually build 22 GPS IIIF satellites.

While the GPS III satellites use a 70 percent digital Mission Data Unit, the one in the new GPS IIIF payload will be fully digital. According to L3Harris, the new system will “provide more powerful signals and ensure flawless atomic clock operations.”

“The digital payload is flexible enough to adapt to advances in GPS technology and future warfighter mission needs,” said Ed Zoiss, president of L3Harris' space and airborne systems. “Proceeding to the next stage in the GPS IIIF navigation payload development process moves the program closer to supporting evolving Air Force mission requirements.”

With the critical design review complete, L3Harris can move forward with final development, test and delivery. The company has contributed navigation technology to every GPS satellite in orbit.

While L3Harris is designing the navigation payload, Lockheed Martin is the prime contractor for GPS IIIF. The Air Force awarded Lockheed Martin more than $1.3 billion to build the first two GPS IIIF satellites in 2018. Critical design review for the platform is expected in March 2020, according to Space Force budget documents released Feb. 10. Once that is complete and the program passes Milestone C in the third quarter of FY2020, the Space Force will begin procuring additional GPS IIIF satellites with annual contract options.

Delivery of the first GPS IIIF satellite is expected in 2026.

Among their advanced features, GPS IIIF satellites will boast regional military protection capabilities, which allow them to deliver regionally-limited high-power M-Code signals. It will also include new laser retro-reflector arrays that can provide on orbit position determination.

Furthermore, the GPS IIIF satellites are being designed to potentially incorporate technology from Navigation Technology Satellite 3, an Air Force Research Laboratory space vehicle that will be used to test a variety of position, navigation and timing technologies. L3 Harris is the prime contractor on that program, which recently passed its preliminary design review.

https://www.c4isrnet.com/battlefield-tech/space/2020/02/12/the-next-gps-payload-will-be-fully-digital/