Moon crane to take a load off lunar landers

The European Space Agency’s Argonaut landers will bring up to 1500 kg of cargo to the Moon. Ranging from rovers and science instruments to building blocks for lunar infrastructure, the weighty goods will need to be offloaded from the lander onto the lunar surface.

Some cargo, like sensitive science instruments, will need to be placed metres away from the lander for uninterrupted measurements, far beyond the reach of robotic arms.

Romanian research institute COMOTI, together with Initium Space, developed a specialised lunar crane that can lift up to 1000 kg of cargo off a lunar lander like Argonaut and place it up to six metres away. The project, called Loader, is supported by ESA’s Technology Development Element.

A scaled model of the crane was tested in ESA’s Planetary Robotics Laboratory in the Netherlands. Watch it move a payload mock-up around the lab.

“This scaled model is only able to lift 30 kg under Earth gravity, equivalent to a little over 180 kg on the Moon, but it allows us to test the functionality and accuracy of the device in a lab environment,” comments Gunter Just, ESA’s robotics engineer. “Ultimately, the crane will be more than twice as big, and with the Moon’s gravity being six times weaker than on Earth, it will be able to lift up to a tonne of material.”

Daniel Useriu from COMOTI explains: “The crane will be launched in a folded configuration on the lander’s payload deck and will deploy once it reaches the lunar surface. A dedicated cable-management system and a carefully defined unfolding sequence ensure that the crane is very compact when stowed while still easy to control and deploy.”

A special levelling system keeps the crane vertical even if the lander comes to rest on sloped terrain. Above the base, a long arm connected by two joints ends in a set of grippers – a passive, spring-loaded one that can lock into place without power, and a battery-powered one that can rotate the load for more precise positioning.

“I am very proud of what the COMOTI team, in collaboration with Initium Space, has achieved with this demonstrator,” concludes Daniel. “We have successfully met, and in some areas exceeded, our initial expectations. There is still a great deal of work ahead to refine the crane, but this demonstrator gives us a strong foundation for the next steps.”

[Image description: A wide view of the European Space Agency’s Planetary Robotics Lab, showing the lab’s indoor test area designed to resemble a rocky planetary surface. The ground is covered in orange sand. In the centre, a wheeled platform supports a long crane arm, which stretches above the test area and holds a metal cube suspended above the ground. A bright light illuminates the crane, while the surrounding areas remain dim. A blue banner overhead displays the ESA logo and the name of the Planetary Robotics Lab.]