Pulsar-based Navigation and Time Keeping for Space Exploration

Workshop Overview:

As the United States and its international partners prepare to expand human and robotic exploration of the Moon, Mars, and beyond, the need for precise, autonomous timekeeping and navigation has become critical. Current approaches rely on Earth-based infrastructure such as GPS constellations, radio ranging, and communications links — systems that are costly to deploy, degrade with distance from Earth, and are vulnerable to communication disruptions. Millisecond pulsars, rapidly rotating neutron stars that emit highly regular pulses across radio, X-ray, and gamma-ray wavelengths, offer a compelling alternative. With long-term fractional frequency stability rivaling that of atomic clocks and microsecond timing precision, pulsars can serve as cosmic, natural, universal timing beacons accessible anywhere in the solar system and beyond, providing autonomous positioning, navigation, and timing (PNT) independent of Earth-based systems.

The overall goal of the workshop is to define potential operational systems that incorporate either X-ray or radio sensors to provide pulsar measurements that enable autonomous navigation and timekeeping for interplanetary (or interstellar) spacecraft or lunar surface systems. We will also scope out the science and technology roadmap to develop them and understand the potential performance and niche’s they occupy in a complete navigation system.

The five-day program will open with short courses to establish common vocabulary across disciplines, followed by morning presentations and afternoon breakout sessions addressing instrument design, mission architectures, technology gaps, and pathways to demonstration missions. Early-career participants will contribute through poster sessions and direct involvement in study activities.

Some of the key objectives are to:

• Identify concrete use cases of pulsar-based navigation and timekeeping, and assess regimes where pulsar navigation provides an advantage relative to other techniques
• Define two strawman instrument concepts, one in the X-ray band and one in the radio
• Characterize the optimal performance of a pulsar navigation/timing system based on the properties of known pulsars and ensembling techniques
• Define a roadmap for operational instrument development and engender collaborations among participants to write funding proposals.
• Evaluate use cases for relevant scientific applications (e.g., Earth-Moon VLBI, BHEX), as well as for current and future NASA missions spanning Moon, Mars, and beyond.
• Seek out mission opportunities for technology demonstration flights

We will produce a final report summarizing the key findings of this workshop for NASA, ESA, and other key stakeholders, and intend to publish results in a peer-reviewed journal. Our findings will establish a clear implementation plan, outlining actionable steps for development of operational systems in both the radio and X-ray band.