GPS World, February 2019

SYSTEM SYSTEMS OF Policy and System Developments GPS Galileo GLONASS BeiDou T he U S Air Force Research Laboratory and the Space and Missile Systems Center selected Harris Corporation as the prime contractor to build Navigation Technology Satellite 3 NTS 3 the nextgeneration experimental positioning navigation and timing PNT spacecraft The satellite is expected to launch in 2022 with one year of experimental operations Geosynchronous Testbed NTS 3 will integrate several advanced technologies to test and demonstrate resiliency and new concepts of operation to include experimental antennas flexible and secure signals increased automation and use of commercial ground assets It will operate geosynchronously hovering above approximately the same spot on Earth throughout its lifetime Technologies matured and knowledge gained from NTS 3 are expected to transition to future generations of GPS and augmentation layers for national PNT capabilities Agile Waveform Platform In support of NTS 3 Harris plans to develop the Agile Waveform Platform a digital signal generator that can be reprogrammed on orbit enabling operators to quickly develop and deploy new signals to meet rapidly evolving needs on the battlefield Additionally Harris electronically steerable phase array antenna will support simultaneous broadcast of multiple waveforms in both Earthcoverage and spot beam configurations NTS 3 will use Northrop Grumman Innovation Systems ESPAStar bus building on AFRLs EAGLE spacecraft that launched in April 2018 NTS 3 was selected as the Space Vehicle Directorates next major integrated space experiment in 2015 and it represents AFRLs first PNT flight experiment to prototype a more resilient PNT multi layer architecture 10 GPS WORLD WWW GPSWORLD COM FEBRUARY 2019 in accordance with the Space Enterprise Vision SEV and the Space Warfighting Construct SWC Heritage NTS 3 builds on a history of Department of Defense DoD satellite navigation SATNAV programs that began in the 1970s with the predecessors of the modern GPS constellation NTS 1 was developed by the Naval Research Laboratory NRL and launched in 1974 with two rubidium vapor frequency standards that advanced the timing and navigation precision demonstrated by the earlier TIMATION satellites NTS 2 launched in 1977 as the first NAVSTAR GPS Phase I satellite and demonstrated cesium frequency standards and a worldwide network for data acquisition There has been no major DoD SATNAV developmental program since then until NTS 3 In 2017 AFRL restructured NTS 3 to emphasize mission objectives to demonstrate disaggregated resilient PNT in a multi layer space architecture as outlined by the SEV and the SWC NTS 3 will provide space qualification for core technologies such as on orbit digital signal reprogrammability and solid state amplifiers In addition to new signals onboard experiments include improvements to timing accuracy and integrity including ensembling to improve long and short term stability NTS 3 will demonstrate key tactics techniques and procedures TTPs for multi layer PNT through all three segments of the SATNAV system space control and user Ground Control Braxton Technologies was selected to handle NTS 3 SATNAV ground control Collaborators AFRL RV is seeking collaboration from industry government agencies and universities in developing experimental concepts and participating in the flight experiment Beyond GPS III NTS 3 The Next Chapter Illustration Lt Jacob Lutz AFRL Space Vehicles Directorate