A new robot, dubbed “E-walker,” with greater dexterity than any before, has been designed to help in construction projects such as the assembly of telescopes and maintenance of space stations in orbit.
More than ever before, as humanity spreads our collective wings, we need to build and maintain facilities in space. Off world, conditions are pretty extreme, and our technology has a limited lifespan due to cosmic rays and solar storms from the sun.
Extravehicular activities (endeavours performed by astronauts outside their spacecraft), robotics and autonomous systems already play a role in servicing and maintenance missionsincluding manufacturing, assembly, maintenance, astronomical and Earth observations, and debris removal.
But advances in robotics and autonomous systems are being pushed in the hope of reducing the risk to humans.
See, we’re not very well built for space. Not being able to breathe without very expensive machinery strapped to a very expensive spacesuit is a problem to begin with. Add to that the harmful rays, lack of gravity, isolation, and any number of things which can go wrong (just watch the film Gravity…) and you have yourself a pretty stressful construction site.
A team of engineers has designed a state-of-the-art ‘walking robot’ that could transform the way we do large construction projects in space. They tested their robot for the building in space of a 25-metre Large Aperture Space Telescope (LAST). Their findings are published in the Frontiers of Robotics and AI journal.
“We need to introduce sustainable, futuristic technology to support the current and growing orbital ecosystem,” explains corresponding author Manu Nair, a PhD candidate at the University of Lincoln in the UK. “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.”
Space construction has become especially topical with the launch of the Hubble Space Telescope and its successor the James Webb Space Telescope. The things we’re putting into space (which require in-space assembly and maintenance) are getting bigger and more complex.
Large telescopes like these can’t be assembled on Earth and launched due to their size. They have to be assembled in space.
“The prospect of in-orbit commissioning of a LAST has fuelled scientific and commercial interests in deep-space astronomy and Earth observation,” says Nair. “Although conventional space walking robotic candidates are dexterous, they are constrained in manoeuvrability. 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.”
Nair’s team has proposed a robot with seven degrees of freedom, coming from seven joints in its limbs. The robot can move along a surface to perform different task and has been dubbed an “E-Walker”.
Simulations of the E-Walker’s capabilities were compared to the existing Canadarm2 and European Robotic Arm on 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” Nair says.
A scaled-down prototype for Earth-based tests has also been developed.
“The analysis of the prototype identifies it to be an ideal candidate for servicing, maintenance, and assembly operations on Earth, such as carrying out regular maintenance checks on wind turbines,” Nair says.
Having done the design engineering analysis, the next steps include verifying whether the robot actually works in a space build.
The E-Walker prototyping work is now in progress at the University of Lincoln which hopes the experimental verification and validation will be published separately.