Well, the new MARM robot is a bit reminiscent of them – except it has three limbs, for optimum dexterity and mobility.

Currently in functional prototype form, MARM was created by a team at the Istituto Italiano di Tecnologia (IIT), led by Nikolaos Tsagarakis. He previously brought us the WALK-MAN firefighting humanoid robot, along with the two-armed/four-legged Centauro.

Its name an acronym for Multi-Arm Relocatable Manipulator, MARM was developed as part of the European Space Agency's MIRROR (Multi-arm Installation Robot for Readying ORUs and Reflectors) project. And while the robot could conceivably perform a wide variety of tasks, it was designed first and foremost to make its way across the outside of spacecraft, installing and/or removing orbital replacement units. Called ORUs for short, the latter are essentially any modular spacecraft components that can be readily replaced as needed.

In a nutshell, the robot consists of a swiveling pelvis-like base and three articulated limbs that are used as both arms and legs.

A latching mechanism on the bottom of each foot/hand engages the hexagonal insulating tiles that cover the outside of most spacecraft, keeping MARM securely in place. That same mechanism can be used to replace the tiles if necessary, and to both charge the robot's battery and send/receive data via docking stations on the outside of the spacecraft.

One advantage of MARM's design is that by walking on three legs, the robot maintains at least two points of contact at all times, plus it can easily move in any direction. Additionally, when using one limb and its moveable pelvis to perform a task, the other two limbs both serve as anchors, providing an extra-stable operating platform.