News from the U.S. Air Force Research Laboratory (AFRL)
The Navigation Technology Satellite-3 (NTS-3) Vanguard program has reached a milestone in preparation for launch of the satellite in late 2023. NTS-3 is expected to push the boundary of positioning, navigation and timing (PNT) technology, paving the way for a more flexible, robust and resilient architecture for satellite navigation.
Prime contractor L3Harris Technologies delivered the NTS-3 space vehicle to an Air Force Research Laboratory (AFRL) integration and test facility at Kirtland Air Force Base, New Mexico. The satellite integrates an agile PNT payload with a Northrop Grumman ESPAStar bus to provide a space platform for AFRL and partner organization experiments and integrated capability demonstrations.
In 2019, the U.S. Air Force designated NTS-3 one of the first three Vanguard programs to deliver innovative, game-changing capabilities to the warfighter at an accelerated pace. NTS-3 is managed by the AFRL Transformational Capabilities Office and has program partners in both the U.S. Space Force and the U.S. Air Force.
“This major milestone marks the transition from space system development at contractor’s facilities to the final stage of integration and test activities,” said Arlen Biersgreen, NTS-3 program manager. “The AFRL team will be overseeing and working closely with L3Harris and other key industry partners to apply an effective combination of contractor and government resources to successfully complete this phase of the effort.”
AFRL and L3Harris are now completing the remaining intra-payload and payload-to-bus functional and performance tests, including the first radio frequency broadcast tests of the novel PNT signals that will be demonstrated from near-geosynchronous orbit after the NTS-3 launch.
Following those activities, the team will perform standard space environment tests that simulate the launch and space environments to verify that the system is ready for the rigors of experimental operations in space. Biersgreen added that experimental performance data from ground testing will be available for sharing with program partners in the next several months.
The Global Navigation Satellite System Test Architecture, or GNSSTA, developed by the Mitre Corporation in partnership with the AFRL Sensors Directorate, is crucial for meeting end-to-end NTS-3 mission objectives. GNSSTA is a reprogrammable software-defined receiver allowing users to receive both legacy GPS and advanced signals generated by NTS-3. It lays the groundwork for future operational receivers to provide the Space Force with options to prevent and respond quickly to common threats on the battlefield, such as GPS jamming and spoofing.
Joanna Hinks, NTS-3 principal investigator, worked closely with the Sensors team on GNSSTA development and testing. “The entire team is excited that earlier this month, we successfully generated signals on the actual spacecraft and received them with our experimental GNSSTA user equipment,” Hinks said. “Showing the space segment and user segment working together like that is an important step to being ready to conduct experiments on-orbit.”
NTS-3 is the first U.S. experiment of its kind in nearly 50 years, since the Navy Research Laboratory’s NTS-1 and NTS-2 spacecraft led the way for the GPS constellation in the 1970s.
“This Vanguard not only aims to support GPS users through vital development of new technologies and techniques, but also to show how an agile and responsive U.S. satellite navigation architecture is paramount to defeating the most challenging threats to warfighter success, both today and through the coming decades,” Biersgreen said.
