Lunar Impact Surveyor Eye Test
ESA’s newly approved Lunar Meteoroid Impact Observer, Lumio, is an exciting mission that will orbit an Earth-Moon Lagrange point to detect meteoroid flashes on the night-time lunar farside. This briefcase-sized 12-unit ‘CubeSat’ – a low-cost small spacecraft built up from standardized 10 cm boxes – will be placed in orbit around the Earth-Moon Lagrange Point 2, a point of gravitational equilibrium between the two bodies.
Lumio’s ambitious goals don’t stop there. In addition to its primary objective of detecting meteoroid impacts, the mission will also perform an innovative autonomous navigation experiment. Using its camera images, Lumio will calculate its current orbital position and distance from the Moon, paving the way for low-cost autonomous navigation in cislunar space without relying on ground stations.
The mission was one of two winning concepts from the ESA SysNova Lunar CubeSats for Exploration challenge and has now received funding through the ‘Fly’ Element of ESA’s General Support Technology Programme, aimed at early demonstration of promising technology in space.
Lumio is being developed by a consortium including:
- Politecnico di Milano
- Argotec
- Leonardo
- IMT-Ingegneria Marketing Tecnologia
- Nautilus
- ECAPS
- LMO
- S&T Norway
With its innovative approach to autonomous navigation and its unique mission to study meteoroid impacts on the lunar farside, Lumio promises to be a groundbreaking mission that could pave the way for future low-cost exploration of cislunar space.
To develop and test the necessary vision-based navigation algorithms for Lumio’s ambitious autonomous navigation experiment, a new variable magnification, hardware-in-the-loop testbed called ‘Retina’, or Realistic Experimental FaciliTy for vision-based Navigation, has been developed.
Retina is composed of several opto-mechanical parts installed along two parallel optical lines in an optical bench in a darkroom. Both lines replicate the same setup, consisting of:
- A high-resolution, high dynamic range microdisplay screen displaying synthetic scenes of the Moon
- A ‘collimator’ lens system that can project the observed scenes at infinity
- A relay lens assembly to achieve variable magnification capabilities
- A camera instrument mimicking the characteristics of real vision-based systems
The microdisplay screen is linked to the collimator lens system, which projects the synthetic lunar scenes at an infinite distance, replicating the conditions Lumio will encounter in deep space. The relay lens assembly allows for variable magnification, enabling the simulation of different distances between the spacecraft and the Moon.
Retina has been developed by the Deep-space Astrodynamics Research and Technology (DART) group at Politecnico di Milano’s Department of Aerospace Science and Technology, which is overseeing the Lumio project for ESA.
Francesco Topputo, Professor of Space Science at Politecnico di Milano, explains the significance of this testbed: “If this experiment can indeed determine Lumio’s position without any ground station in the loop, it would pave the way for low-cost autonomous navigation in cislunar space.”
By accurately simulating the visual conditions Lumio will experience during its mission, Retina will play an important role in developing and validating the vision-based navigation algorithms that will enable the spacecraft to autonomously determine its position and distance from the Moon.