A diminutive four-legged robot looks set to become the UK’s first visitor to the moon. Jon Excell reports
From the 2016 Rosetta comet landing, to the development of the Mars rover for ESA’s forthcoming mission to the red planet, British space scientists and engineers are at the heart of some of the world’s most ambitious and challenging space-exploration efforts. Which makes it all the more surprising that our nearest cosmic neighbour – the moon – has never been visited by a UK developed probe or robot. Until now that is.
Because in the summer of 2021 – if all goes according to plan – this notable gap in the sector’s CV looks set to be plugged when a small rover developed by UK startup Spacebit becomes the first British built craft to reach the lunar surface.
Perhaps even more intriguingly , this diminutive robot (which weighs around 1.3kg and is built on a 10x10cm cube sat frame) will break the mould for planetary rovers, which typically move about on tracks, and instead scuttle across the moon’s surface on four spider-like legs. According to Spacebit CEO Pavlo Tanasyuk, the autonomous battery-powered rover – known as “Asagumo” – will be the first legged robot to explore anywhere other than Earth.
The curious looking system will hitch a ride aboard one of the first new wave of commercial lunar spacecraft; Astrobotic’s Peregrine lunar lander – currently scheduled to launch in June 2021 – where it will share the journey with around 30 other payloads including a number from NASA, with whom Astrobotic has a $79.5m contract.
On arrival, Asagumo’s initial aims are modest: demonstrate the core technology by crawling a few metres over the lunar surface and use a suite of cameras and LIDAR sensors to gather data. But if this first mission is a success, Tanasyuk hopes that the rover could put the UK firmly at the forefront of a lunar resources market that is expected to be huge in the years ahead.
Talking to The Engineer late last year, Tanasyuk explained that whilst he has always had a fascination with the moon, Spacebit – which was founded in 2014 – originally started out as an effort to build a decentralised organisation that uses blockchain technology for space-based data applications. Whilst this remains a key aim, the recent emergence of private space organisations with the capability to deliver payloads to the moon has, he said, accelerated ambitions to actually put a vehicle on the lunar surface.
He added that a walking vehicle has been chosen because it is thought to represent the best option for accessing hard to reach crevices and tunnels, and gathering valuable data that could be key to enabling humans to both tap into the moon’s mineral resources and identify natural structures and materials that could one day be used to build a sustainable habitat.
The team is particularly interested in using the robot to explore the moon’s lava tubes: natural tunnels formed in its geological past that are thought to hold promise for future human habitations. “Astronauts, when they go back, will have to build structures on the lunar surface, or underneath it, so that you can sustain life or a colony on the moon,” said Tanasyuk. “If you have a lava tube, you already have an environment that is shielded from radiation and many other things. You are getting an environment where you can already store stuff, and you can live and work there.”
Tanasyuk admits that it is unlikely that the rover will get an opportunity to explore these sub-surface tunnels during its maiden mission, but is confident that the group has overcome many of the key challenges that will make this possible in future visits.
One of these is the development of robotic legs that are able to cope with the varied depth and consistency of the lunar regolith (or soil) which feature snowshoe like footers to prevent the rover from sinking into the surface. Tanasyuk said that the team is also experimenting with different gaits for different ground conditions. “Altering the gait, we can choose the optimal parameters for a particular area, manage the balance between speed, stability, energy consumption,” he said.
Another key challenge has been around packaging all of the system’s electronics and sensor payload into such a small and lightweight design, something that Tanasyuk said has led to a number of trade-off and compromises in terms of things like battery weight.
However, whilst the rover’s relatively small size does present some major challenges, it could also prove to be its biggest advantage, said Tanasyuk, who believes the concept could fundamentally change the approach to planetary exploration. “The reason it is small is that ultimately we believe it can change the approach to space exploration,” he said. “If you can send something which is smaller and cheaper then you can send multiple systems and you can also allow for risk. We can have more data and more exploration at lower cost,” he said
Whilst Asagumo’s unusual appearance and unconventional method of locomotion means that it’s destined to grab many of the headlines, Spacebit is not pinning all of its hopes on a legged rover. Indeed, at the time of writing it had announced plans to send a second wheeled rover, aboard another privately developed lander – this time Intuitive Machine’s Nova-C vehicle, which is due to arrive at the moon’s Vallis Schroteris in September or October of next year.