The future of space construction may have just been revolutionized by a new walking robot

The E-Walker has been tried and tested on Earth, but it's yet to prove itself in space.
Fabienne Lang
Moon tractor
Moon tractor

iStock/Vitaly Kusaylo 

Large construction projects in space may be one step closer to reality, thanks to a new walking space robot.

Researchers have designed the E-Walker – a state-of-the-art walking robot – to take on the behemoth task of space construction. A robot prototype has already been tested here on Earth by assembling a 25m Large Aperture Space Telescope. The telescope would usually be built in space, which is the E-Walker's future duty.

Doubling up on its potential duties, a smaller-scale prototype of the same robot has also been created and shows promise for large construction applications on Earth, such as maintenance of wind turbines.

The team's findings were presented in the journal Frontiers in Robotics and AI.

In-Space construction

It's imminent. In-Space construction has been on the radar for a while. For instance, China and Russia are looking to build a Moon base, while space cement is now ready and could be used in construction projects on the Moon and Mars.

Building, maintaining, and servicing large construction projects could not be any harder or more needed than in space, with the potential exception of deep-ocean ones. Conditions are extreme, and human-made technology deteriorates quickly up there.

This is where robotics and autonomous systems come into play. They have already proved useful for servicing and maintenance missions and have helped the space community conduct ground-breaking research on various space missions.

“As the scale of space missions grows, there is a need for more extensive infrastructures in orbit. Assembly missions in space would hold one of the key responsibilities in meeting the increasing demand," explained the corresponding author of the recent study, Manu Nair, Ph.D. candidate at the University of Lincoln.

In their paper, Nair and his colleagues introduced an innovative, dexterous walking robotic system that can be used for in-orbit assembly missions.

As space missions keep improving and pushing new boundaries, so do their maintenance and construction projects. Space agencies and companies have created bigger and more complex projects, like the James Webb Space Telescope. The telescope has newer and larger apertures than any seen before, and this trend is only set to continue.

Assembling such telescopes on Earth is becoming more and more impossible due to the limited size of current launch vehicles. This is why more of these telescopes need to be assembled in orbit. And this is where autonomous robots, like the one designed by Nair's team, come into play.

“Although conventional space walking robotic candidates are dexterous, they are constrained in maneuverability. Therefore, it is significant for future in-orbit walking robot designs to incorporate mobility features to offer access to a much larger workspace without compromising the dexterity," said Nair.

The new E-Walker robot

The newly-proposed robot is called the E-Walker, and it is a seven-degrees-of-freedom fully dexterous end-over-end walking robot (a limbed robotic system that can move along a surface to different locations to perform tasks with seven degrees of motion capabilities).

The team compared it to the current Canadarm2 and the European Robotic Arm, based at the International Space Station.

“Our analysis shows that the proposed innovative E-Walker design proves to be versatile and an ideal candidate for future in-orbit missions. The E-Walker would be able to extend the life cycle of a mission by carrying out routine maintenance and servicing missions post assembly, in space,” explained Nair.

More has yet to be done before the new E-Walker is shipped off to space, though. The research was limited to the design engineering analysis of a full-scale and prototype model of the E-Walker. Nair explained: “The E-Walker prototyping work is now in progress at the University of Lincoln; therefore, the experimental verification and validation will be published separately.”


The E-Walker’s detailed design engineering includes the structural finite element analysis results for space and earth-analogue design and the corresponding actuator selection methods. Results of the modal analysis demonstrate the deflections in the E-Walker links and end-effector in the open-loop due to the extremities present in the space environment. The design and structural analysis of E-Walker’s scaled-down prototype is also presented to showcase its feasibility in supporting both in-orbit and terrestrial activities requiring robotic capabilities over an enhanced workspace. Further, the mission concept of operations is presented based on two E-Walkers that carry out the assembly of the mirror modules. The mission discussed was shortlisted after conducting an extensive trade-off study in the literature. Simulated results prove the dual E-Walker robotic system’s efficacy for accomplishing complex in-situ assembly operations through task-sharing.

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