Lunar Pathfinder

An artist impression of Lunar Pathfinder connecting to Earth navigation satellites from lunar orbit.

Lunar Pathfinder is the first element of Moonlight, ESA’s future communications and navigation service for the Moon. The mission will provide Europe’s first dedicated lunar communications infrastructure while paving the way for a future lunar service constellation.

Lunar Pathfinder will carry RADMON – a radiation monitor developed by Thales Alenia Space in Switzerland that will characterise radiation conditions around the Moon – and demonstrate, for the first time on a lunar-orbiting spacecraft, the simultaneous use of radio, a Global Navigation Satellite System (GNSS) and laser-ranging techniques. To this end, the satellite contains: 

• A GNSS receiver developed by SpacePNT in Switzerland under an ESA navigation contract to investigate whether Earth navigation satellite systems can be used from the Moon.  

• A NASA laser retroreflector to support laser ranging measurements between Earth and lunar orbit. 

• An X-band transponder developed by Thales Alenia Space in Spain to investigate two-way radio ranging measurements using ground stations such as ESA’s ESOC site.  

Together, these demonstrations will contribute to the technologies needed for precise positioning and navigation around the Moon.