The robotic hand designed to collect samples on other worlds is getting its mechanical fingers assembled.

This picture shows the mechanism that allows ESA’s Sample Transfer Arm to pick up tubes filled with precious regolith – the dust, soil and rock on the martian surface – for analysis back on Earth.

The “hand” of the robotic arm, or end effector, uses two tools to seize its treasure: fingers to grip sample tubes tightly but with care, and a plunger to insert them into a container destined for Earth. In this image, a technician holds the black gripping jaws together during assembly.

A clever mechanism allows the robot to switch between tools, despite both being driven by a single motor – an efficient design that reduces mass and volume, critical factors for any space mission.

European engineers at Added Value Solutions (AVS) from Spain assembled the end effector for testing and keep building expertise for future missions. This engineering model confirms that the mechanism works as intended.

Initially designed for Mars Sample Return to transfer samples to a rocket for the journey home, the technology behind this robotic helping hand also has high potential for applications on the Moon and in low Earth orbit.

Watch the prototype in action in the article “Grip on Mars”.