ESA is working with Russia’s Roscosmos space agency to venture to the Moon on their Luna missions. Three missions are planned in the next few years and European technology will pilot them and drill into the lunar surface, as well provide ground support with ESA’s network of satellite dishes.
When Luna-25 lands near the south pole, it will scan the terrain with Europe’s “Pilot”. Two cameras and a laser-radar – lidar – will image the landscape to test the system for future landings. Luna-25 will land using its own systems but the data collected by Pilot will be used to prepare for the real thing: autonomous landing of a spacecraft on the Moon with European technology.
Two years after Luna-26, Luna-27 will be sent into lunar orbit for observations, sending its data back to ground stations that include ESA’s network.
Luna-27 will be larger than its predecessor and will land closer to the south pole under Pilot’s guidance and navigation.
Similar to face recognition software on a mobile phone but far more difficult, Pilot identifies landmarks such as craters during descent and matches them to a set of landmarks stored in an onboard database.
Pilot will also use the motion of the terrain observed by the camera to improve its estimate of the lander’s velocity.
Two minutes before touchdown, the landing site will come into Luna’s field of view and Pilot’s detailed analysis will begin. Think of automatic car parking but travelling at high speeds and the parking place is on the Moon in partial darkness – with no second chance.
At this stage, the navigation camera will be supported by a scanning lidar sensor, which uses laser pulses to reconstruct landing site topography.
Whereas the camera needs light to capture images of the Moon, the lidar is impervious to the harsh lighting conditions in the polar region. Similar technology was demonstrated with the last Automated Transfer Vehicle when it docked with the International Space Station in 2014. Laser beams scan the view and report to a computer to avoid hazards and choose the ideal landing or docking approach.
Many questions need to be answered by Pilot’s computer. Is the designated landing site sunlit or shaded? Are there large boulders, craters or slopes that could threaten a safe touchdown? Is enough fuel left to change course and reach a safer site?
Prospecting the Moon
Once on the Moon, Luna-27 will deploy the European-built Prospect drill to search for water ice and other chemicals under the surface. Operating at temperatures of –150°C and drilling over a metre down, Prospect first needs to penetrate the frozen surface.
Prospect includes a miniature laboratory to analyse the materials it finds. Precise measurements of the elements it digs up will help to reveal the Moon’s history and indicate whether future explorers could use local resources on their missions to help set up a base.
The south pole region is of great interest to researchers and explorers because the low angle of the Sun over the horizon leads to areas of partial or even complete shadow. These shadowed areas and permanently dark crater floors, where sunlight never reaches, are believed to hide water ice and other frozen volatiles that could be used for fuel.
Last update: 18 April 2018