One of Lunar Link’s antennas during vibration testing at Thales Alenia Space in Cannes, France.

Lunar Link, ESA’s telecommunications contribution to the Gateway, will provide vital communications between the future station, astronauts and infrastructure on the Moon’s surface. NASA’s HALO habitation module will host it, and it will form a key part of humankind’s return to deep space exploration.

Lunar Link’s two antennas were built by Spanish company Sener in Bilbao before being transported in November to prime contractor Thales Alenia Space in France for their assembly, integration and testing campaign.

Mounted on one-metre deployable booms, the antennas will unfold once in space. In December, engineers rehearsed this delicate deployment using a four-metre-wide balloon to simulate weightlessness, to ensure the booms will extend smoothly in space.

The recently completed environmental test campaign verified that the antennas can withstand the extreme stresses of launch and spaceflight. Vibration and acoustic testing exposed them to the intense shaking and sound pressure they will experience during liftoff. Thermal vacuum testing then recreated the harsh condition of space – extreme temperatures and near-vacuum – inside a vacuum chamber large enough to house both 1.25-metre-diameter antennas at once.

With testing complete, the antennas are now safely stored in Cannes while Lunar Link’s central section, the ‘baybox’, finishes its own integration campaign. The baybox houses critical subsystems, including the flight computer that controls Lunar Link’s operations.

Around summer, the antennas and baybox will be integrated to form the complete Lunar Link element. Following final verification tests, it will travel to Northrop Grumman in the United States for installation onto HALO, ahead of launch to lunar orbit aboard a Falcon Heavy rocket.

Step by step and test by test, ESA’s Lunar Link is taking shape, preparing to keep Gateway connected to the Moon.