Eurobot takes the plunge

European engineers recently put a multi-jointed, three-armed robot, dubbed Eurobot, through a series of trials in a pool at the European Astronaut Centre.

Eurobot, which has been under development since 2003, is expected to eventually handle some of the more routine tasks now undertaken by astronauts. One possible application is to help astronauts during spacewalks, but the robot may also be used during human expeditions to the Moon or Mars.

In space, the Eurobot will find its way to a work site on the International Space Station (ISS), perform an inspection and carry out any initial preparatory work, such as the transfer of tools and equipment. Remotely controlled by an operator inside the ISS, Eurobot will, say its developers, be able to multi-task, providing extra hands and eyes for the spacewalkers. Once the astronauts are back inside the ISS, Eurobot will remove the tools and equipment.

'There is a shortage of crew time during all missions, so anything that improves the use of astronaut time is very desirable,' said Gianfranco Visentin, head of ESA's automation and robotics section.

The version of Eurobot being used in exercises is an early prototype called the Weightless Environmental Test (WET) Model, which has been developed for operation in a water tank where the microgravity conditions found in space can be simulated.

Developed for ESA by a consortium led by Thales Alenia Space, the WET Model is similar in size and configuration to the planned Flight Model. It consists of a central 'body' structure with three identical arms, each with seven joints.

Each arm is equipped with a camera and an 'end-effector' which acts as a hand. The WET model has only one type of hand, but the real Eurobot will have a set of three or four interchangeable hands. A head camera on a pan-and-tilt mechanism provides a global monitoring view of the worksite.

In the latest trials, the WET Model was used to verify the operational concept for Eurobot. During tests of its ability to move and manipulate objects, the project team gained hands-on experience of the robot's capabilities, trying out multi-arm control and co-ordination, along with visual recognition of obscured targets.