ESC
Positioning, Navigation, and Timing
NASA navigation engineers serve the Exploration and Space Communications projects division in a variety of ways, supporting missions while developing technologies that enhance spacecraft navigation and guidance.
Navigation
Spacecraft near and far need positioning, navigation, and timing data to successfully execute their science and exploration objectives. As part of NASA’s SCaN (Space Communications and Navigation) Program, ESC’s world-renowned space navigation experts are designing the satellite navigation systems and architectures of the future. ESC assists in the development of next generation space navigation systems that enhance the agency’s exploration capabilities, directly support NASA’s current Artemis missions, and lay the technological foundation for future human exploration of the Moon and Mars.
How does ESC support navigation?
Global Navigation Satellite Systems (GNSS)
ESC navigation experts advocate for mission-critical documentation of Global Navigation Satellite System (GNSS) Positioning, Navigation, and Timing (PNT) capabilities. GNSS refers to several constellations of GPS-like satellites operated by the United States, European Union, Russia, China, India, and Japan. Near-Earth spacecraft have long relied on GNSS signals for accurate positioning, navigation, and timing data, but high-altitude GNSS-based navigation is a priority for the agency. Below an altitude of approximately 1,860 miles, spacecraft in low Earth orbit can rely on GPS for navigation data, just as users on Earth use their phones to navigate highways. Beyond this altitude, spacecraft must use specialized equipment and expanded signals from GNSS. NASA demonstrated GNSS navigation at distances halfway to the Moon in 2019 and, with the Lunar GNSS Receiver Experiment (LuGRE) in 2025, on the lunar surface itself.
Lunar GNSS Receiver Experiment (LuGRE)
To prove and test GNSS capabilities on the Moon, ESC developed the Lunar GNSS Receiver Experiment (LuGRE) in partnership with the Italian Space Agency. In January 2025, LuGRE flew on a Commercial Lunar Payload Services mission delivered by Firefly Aerospace of Cedar Park, Texas. NASA landed LuGRE in Mare Crisium, a basin on the Moon spanning about 460 miles. On March 2, 2025, LuGRE received the first GNSS fix ever recorded on the Moon from both GPS and the European Union’s Galileo. The payload’s data will be used to develop operational lunar GNSS systems for future missions to the Moon.
Flight Dynamics Facility
Managed by the Navigation and Mission Design Branch, Goddard's Flight Dynamics Facility (FDF) provides comprehensive navigation services to crewed and robotic missions in collaboration with NASA's Near Space Network. Services provided by FDF include mission analysis, trajectory design, maneuver planning, operations planning, mission integration, and daily support of over 30 operational spacecraft. The FDF plays a key role in launches, especially human spaceflight missions. They track Commercial Crew Program launches using data from NASA's Tracking and Data Relay Satellite constellation. Their coverage assures the safety of astronauts as they ascend to the International Space Station, even in the unlikely event of contingencies like a launch-abort scenario. The FDF deeply integrated into the ESC teams supporting the Artemis Moon missions, providing critical support to the Space Launch System and the Orion spacecraft during the historic Artemis I launch, orbit, and re-entry in late 2022.
NavCube 3.0 Mini
The NavCube team leverages the successes of NASA's Magnetospheric Multiscale Mission (MMS) and Lunar GNSS Receiver Experiment (LuGRE), which broke the record for furthest acquisition of GNSS signals from Earth at over 116,300 miles in 2019 and on the Moon's surface in 2025. The receiver will provide precise timing and tracking information, potentially enabling autonomous navigation for lunar landers, rovers, and astronauts.
NICER SEXTANT
The Station Explorer for X-ray Timing and Navigation Technology (SEXTANT) uses the ultra-regular oscillations of distant pulsars, a type of neutron star, for accurate timekeeping. Precise measurements of time, usually supplied by atomic clocks, are key to space navigation. The SEXTANT is part of NASA's Neutron star Interior Composition Explorer (NICER) mission, which studies neutron stars from an external module on the International Space Station.
LunaNet
LunaNet is a developing interoperable network architecture designed to deliver continuous communications and positioning, navigation, and timing (PNT) services for Artemis mission crews and spacecraft assets. The navigation engineers at ESC lead the development of LunaNet navigation standards, leveraging Delay/Disruption Tolerant Networking and other innovative capabilities to ensure lunar users can retrieve GPS-like position fixes anywhere on and around the Moon.
Navigation Benefits
Innovation at Home and Beyond
Exploration and Space Communications provides missions with onboard and on Earth navigation support and technology innovations, enabling new mission capabilities including distributed space missions, in-space assembly, low-latency operations, lower reliance on ground assets, and reduced operations costs. In addition to its essential role in coordinating mission positioning and communications, ESC’s navigation project significantly benefits space exploration by reducing mission cost, schedule, and risk and increasing scientific return.
quick facts
Beyond low Earth orbit, spacecraft navigate using specialized equipment and expanded signals from the Global Navigation Satellite Systems (GNSS), including GPS and similar satellites operated by the EU, Russia, China, India, and Japan.
Simulations developed by Goddard Space Flight Center navigation engineers show that GPS and GNSS signals could help navigate the Gateway, NASA’s planned lunar outpost.
Before NASA’s Lunar GNSS Receiver Experiment (LuGRE), the Magnetospheric Multiscale (MMS) mission captured a GPS fix at over 116,300 miles from Earth, or about halfway to the Moon.
Below an altitude of approximately 1,860 miles, spacecraft in low Earth orbit can rely on GPS for navigation data, just as users on Earth use their phones to navigate highways.
NASA’s Lunar GNSS Receiver Experiment (LuGRE) made the first GNSS position fix on the surface of the Moon in March 2025.
In 2017, Goddard Space Flight Center demonstrated navigation by X-ray emissions from rapidly rotating neutron stars called pulsars. This technology may hold practical applications for upcoming missions to the Moon, Mars, and beyond.
The Flight Dynamics Facility at Goddard Space Flight Center plays a pivotal role in launches for crewed and robotic missions, assisting Near Space Network personnel with critical insights and navigation data.
NASA’s Lunar Communications Relay and Navigation System (LCRNS) project is verifying and validating the commercial services that will provide Artemis astronauts and rovers continuous communications and positioning data anywhere in lunar orbit.
Navigation News
NASA Explores Upper Limits of Global Navigation Systems for Artemis
Record-Breaking Satellite Advances NASA’s Exploration of High-Altitude GPS
NASA Navigation Tech Shows Timing Really Is Everything
NASA Tests Atomic Clock for Deep Space Navigation
The Lunar GNSS Receiver Experiment (LuGRE)
This technical paper provides an overview of LuGRE, a joint NASA-Italian Space Agency (ASI) payload, including its design, concept of operations, objectives, and simulated performance results. Written and presented in 2022 for the ION GNSS+ conference held in Denver, Colorado.
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