Figure A


Figure B


Figure C
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Engineers and technicians prepare NASA's Cold Operable Lunar Deployable Arm (COLDArm) robotic arm system for testing in a thermal vacuum chamber at the agency's Jet Propulsion Laboratory in Southern California in November 2023.

Successful testing in this chamber, which was reduced to minus 292 F (minus 180 C), demonstrates the arm can withstand the conditions it would face on the surface of the Moon.

Figures A and B show different angles of engineers and technicians preparing the arm for testing in the chamber.

Figure C is a close-up of the arm, in its stowed position, mounted on a cold plate inside the chamber. During the test, liquid nitrogen flows through the plate to keep the temperature low.

To operate in the cold, COLDArm combines several key new technologies: gears made of bulk metallic glass, which require no wet lubrication or heating; cold motor controllers that don't need to be kept warm in an electronics box near the core of the spacecraft, and a cryogenic six-axis force torque sensor that lets the arm "feel" what it's doing and make adjustments.

A variety of attachments and small instruments could go on the end of the arm, including a 3D-printed titanium scoop that could be used for collecting samples from a celestial body's surface. Like the arm on NASA's InSight Mars lander, COLDArm could deploy science instruments to the surface.

Motiv Space Systems, which is collaborating with JPL on COLDArm, developed the cold motor controllers and built sections of the arm, assembling it from JPL-supplied parts at the company's Pasadena, California, facility. The COLDArm project is funded through the Lunar Surface Innovation Initiative and managed by the Game Changing Development program in NASA's Space Technology Mission Directorate.