Thursday 25 September 2025
As space agencies and private companies continue to push the boundaries of exploration, a new technology is being developed that could revolutionize our ability to navigate through deep space. Stellar occultations, or the timing of stars disappearing behind the Moon’s limb, have long been used as a way to determine the position of spacecraft in lunar orbit. But researchers are now exploring whether this technique can be applied to even more challenging environments, such as near small bodies like asteroids and comets.
The Lunar Meteoroid Impact Observer (LUMIO) mission is a CubeSat that will be launched into a quasi-Halo orbit around the Earth-Moon L2 point in the coming years. Its primary goal is to observe and characterize micro-meteoroid impacts on the lunar far side, providing valuable insights into the Moon’s composition and geological history.
But LUMIO also presents an opportunity to test the use of stellar occultations for navigation in deep space. By monitoring the precise timing of stars passing behind the Moon’s limb, researchers can determine the spacecraft’s position with much greater accuracy than traditional methods. This is particularly important during periods when radiometric tracking data is limited or unavailable.
A team of scientists from the University of Bologna has been working on developing a simulation tool to identify valid occultation events and exclude non-observable cases. They used JPL’s MONTE library to create a batch least-squares filter that incorporates these measurements alongside conventional radiometric data. The results show that incorporating occultation observables reduces the transverse and normal position uncertainties of LUMIO by up to a factor of two, especially during tracking gaps or occultation-rich arcs.
One of the key challenges in using stellar occultations for navigation is the need for accurate timing data. Any errors in measuring the time it takes for a star to disappear behind the Moon’s limb can significantly impact the accuracy of the spacecraft’s position determination. However, recent advancements in clock technology have made it possible to achieve sub-second accuracy, which is essential for this technique.
The potential applications of stellar occultations go far beyond the LUMIO mission. As space agencies and private companies continue to explore the solar system, they will need more accurate and reliable methods of navigation. This technique could be used to determine the position of spacecraft near small bodies like asteroids and comets, which are notoriously difficult to navigate.
In addition, stellar occultations could potentially be used for autonomous onboard navigation, allowing spacecraft to determine their own positions without relying on external tracking data.
Cite this article: “Stellar Navigation: A New Frontier in Deep Space Exploration”, The Science Archive, 2025.
Here Are The 10 Keywords: Spacecraft Navigation, Stellar Occultations, Lunar Orbit, Asteroids, Comets, Deep Space, Cubesat, Lumio Mission, Radiometric Tracking, Autonomous Onboard Navigation
