The European Space Agency has convened a gathering of more than 60 experts in different areas of science and engineering to design a mission to enter a pit on the Moon’s surface and explore the entrance to a lunar cave.
The Moon is dotted with numerous pits that scientists believe could lead to enormous underground tunnels. Lunar caves such as these offer a geologically pristine record of the Moon’s history and could also provide a safe home for future missions to the Earth’s satellite.
‘A view into the interior of a lunar cave would be true exploration – it would reveal unexpected scientific information,’ said Francesco Sauro, a cave scientist and planetary lava tube expert, and the technical course director of ESA CAVES and PANGAEA.
The ESA kick-started such a mission in 2019, with the launch of a public Open Space Innovation Platform (OSIP) call for ideas to detect, map and explore lunar caves. Five of the submitted ideas were then chosen to be studied in more detail through an ESA Discovery SysNova challenge.
Most recently, the two winning SysNova studies – dubbed RoboCrane and Daedalus – were united and expanded into a single complete mission plan through the ESA’s Concurrent Design Facility (CDF). The mission would use a robotic crane (RoboCrane) to lower a cave explorer (Daedalus) into a lunar pit. On its way down, Daedalus would explore and document the entrance to the cave, before mapping the closest part of the cave at the bottom.
‘The OSIP campaign and SysNova challenge paved the way to the CDF mission analysis,’ said Loredana Bessone, CAVES and PANGAEA project lead and technical officer for the studies. ‘They allowed us to identify the interest in lunar cave missions from European and Canadian industry and research institutes, as well as revealing their expertise. It allowed industry and academia to confront the challenges of such missions and learn from lunar cave scientists about constraints, opportunities and potential mission scenarios.’
By bringing together experts from many different areas of science and engineering – including specialists from the RoboCrane and Daedalus teams, as well as ESA experts – the CDF study came up with a complete vision of a lunar-caves exploration mission, confirming that the mission is both feasible and potentially very interesting, scientifically.
The experts who took part in the CDF study came up with rough designs for the rover that would carry the equipment to the pit, as well as concrete designs for RoboCrane and Daedalus themselves. They also studied the environment of the pit, created models of the Moon’s subsurface and the mission elements, generated roadmaps for developing the technologies that will be needed to make the mission a success and assessed the main challenges that the mission will face.
‘A mission like this would require the development of innovative technologies, encouraging the space sector to develop new solutions compared to previous lunar missions,’ said Sauro. ‘This advancement in technology would be a big step forward for lunar and Martian exploration.’
The teams behind RoboCrane and Daedalus will continue to work on their ideas. Led by the University of Oviedo in northern Spain, RoboCrane researchers published a paper in December 2021 describing their system to provide a power and communication link between the lunar surface and lunar caves for exploration robots.
‘The mission will need to be defined in even more detail during the coming years,’ said Bessone. ‘The rover that will carry RoboCrane and Daedalus to the pit will need to be described and a lunar test range would be required to try out the techniques planned for the mission.’
A ‘Topical Team’ consisting of 17 experts from universities and research institutes across Europe and Canada has now been established to support ESA in the development of a strategy that includes lunar caves in the framework of European lunar exploration. The team is organising a planetary caves conference for 2023.
The mission itself could launch on an Ariane 6 rocket in 2033 at the earliest and would use the European Large Logistic Lander to reach the Moon’s surface. It would target the Marius Hills pit and last a fortnight – equivalent to one day on the Moon.