Key points
- Lava tubes exist on Earth and other bodies in our Solar System and could provide shelter for future human space explorers.
- The German Aerospace Centre has specially designed a rover to explore the complex terrain.
- We are working with them to add our Wildcat SLAM technology to help their rover navigate and support lunar science.
What does an ancient lava tube in the Canary Islands have in common with space exploration?
For our robotics teams, it turns out, quite a lot.
A small group of our researchers travelled to Lanzarote, more than 18,000 km from their home base in Brisbane, to test their navigation and mapping technology with the German Aerospace Centre (DLR) in a lava tube – a tunnel through rock, deep underground.
Their purpose? Understand how DLR's SCOUT Rover would perform in lava tubes much, much further away – beneath the surface of the Moon and Mars.
What is a lava tube?
Lava tubes are natural tunnels created by lava flowing along or under the surface. The outer layer of the lava flow cools, forming a crust. As the hotter lava drains away it leaves behind a tunnel. These tunnels can be up to 65 km long and tens of metres wide. The pitch dark, uneven surface and large rocky obstacles pose significant challenges to robotic and human explorers alike.
The Lanzarote lava tube system is an accessible testing ground for DLR’s SCOUT Rover, tailor-made for navigating the complex terrain. Instead of using traditional wheels, the rover deploys novel spoked wheels and flexible back elements to navigate through and around obstacles.
Of course, Earth isn’t the only planet in our Solar System with lava tubes…
Natural protection from cosmic radiation
Space is dangerous. Without Earth’s protective magnetic field, solar and cosmic radiation poses life-threatening danger to human space explorers.
But it turns out you don’t need a magnetic field to shield astronauts and equipment from the worst space has to offer – you just need rocks and dirt.
Ross Dungavell is a Senior Engineer in our robotics team. He said lava tubes provide ideal shelter from the intense conditions of space.
“On the lunar surface, you get 13.8 days of sunlight, then 13.8 days of night – with temperatures ranging from 130°C to -180°C. In comparison, lava tubes are a constant, mild temperature,” he said.
Along with protection from radiation and harsh temperatures, the lava tubes would protect astronauts from micrometeorite impacts.
“They date back to the Moon’s volcanic activity, so if they exist today, they’ve been stable for one to many billions of years,” Ross said.
“You get to have a look at this very old, very untouched lunar geology [that is] by lunar standards, an extremely pleasant environment.”
Fred Pauling, a Principal Engineer in our robotics team, added that lava tubes offer an array of exciting scientific opportunities.
“It’s potentially a pristine way to inspect the subsurface geology without having to drill. [On Mars] these lava tubes could be places that continue to have life, or signs of life,” he said.
Award-winning autonomous navigation
If you’re looking to explore underneath rocks and dirt, CSIRO is a good place to start.
“Lava tubes really represent, from a technical perspective, an extension of the work we’ve done in other subterranean environments, like underground mine sites and caves,” Fred said.
That work includes Wildcat SLAM – a mapping technology that’s also been deployed on the International Space Station – and Navstack, which uses that information to plot a robot’s course in 3D space.
The technology was deployed at the DARPA Subterranean Challenge, where 11 teams used their tech to autonomously navigate a cave. The team’s work attracted the attention of DLR, paving the way for collaboration on extraterrestrial lava tubes.
Dr Roy Lichtenheldt is the project manager of the DLR SCOUT Rover.
“Caves have many obstacles. If you move around, you can see a lot of breakdowns, big piles of rubble, sometimes even hard to get over as a human,” he explained.
“While we are responsible for the locomotion system, CSIRO supplies perception and autonomy with the LIDAR. Our collaboration helps us to let the rover navigate through the cave without human intervention, which is especially important for us.”
“On the Moon and Mars, we have a signal delay and very short mission duration, so any call back to Earth would cost us precious time. For this reason, the rover has to make decisions on its own and be extremely robust. We want to tune the autonomy, enabling the rover to find its path, while not limiting itself by avoiding too many obstacles.”
To the Moon, infinity, and beyond
Our team returned to Australia with plenty of work to do. Fletcher Talbot is a Senior Robotics Research Engineer in the team.
“It was hard in Lanzarote to really pinpoint exactly what was working and what wasn’t working,” Fletcher said.
“Next steps will be to really delve down into the specifics and understand what components work, what don’t work and what needs to be done to make it more performant.”
They hope to bring a model SCOUT Rover to Brisbane to further integrate the technologies.
From there, the sky is not the limit. With an international effort, the team hopes that future funding could bring the technology to lava tubes on the Moon, and one day Mars.
But for each of them, the experience on Lanzarote is one worth cherishing.
“Everywhere you go, you’re completely surrounded by volcanoes and lava flows. You really got a sense of, if you’re on the Moon, this is the kind of environment you might be faced with,” Fred said.
“It’s the best part of the job, honestly. Seeing our tech out in the real world doing real things … you have to accept some humility because something quite often doesn’t work in the real world,” Fletcher said.
“But the best part of any of this development process is to really understand where the technology falls down and where it exceeds expectations.”