Construction Robots Will Have to Colonize Mars Before Humans
When the first humans finally set foot on Martian soil, it’s unlikely they will find themselves standing in an empty landscape like the crew of Apollo 11. Any future off-world colony will be prepared first by robotic workers who will gather building materials, construct habitats, and undertake dozens of other tasks necessary for paving the way for human arrival.
Uncrewed Cargo Missions
NASA has already proven its ability to autonomously land cargo on Mars, successfully landing the Curiosity Rover which weighs in at 2,200 pounds or one metric ton. A 2019 paper from the University of Illinois College of Engineering predicted that “sending more ambitious robotic missions to the surface of Mars, and eventually humans, will require landed payload masses in the 5- to 20-ton range.”
What would we need to send? Everything necessary for a colony to survive that cannot be constructed from materials found on Mars itself. In 2016, Elon Musk surmised that the equipment, habitats, and supplies needed to build a rudimentary base would include “machines to produce fertilizer, methane, and oxygen from Mars' atmospheric nitrogen and carbon dioxide and the planet's subsurface water ice, and materials to build transparent domes for crop growth.”
Construction materials such as concrete would be prohibitively expensive to lift into Earth’s orbit, let alone transport to Mars, which is why engineers are focused on using regolith (Martin soil) as a building material.
Finally, cargo missions would need to deliver the robots that will put it all together before humans arrive.
What Would Construction Robots Look Like?
Robots on Mars won’t all be built like the Opportunity and Curiosity rovers. Instead, they will differ in design depending on functionality. The task of gathering regolith might best be done by a robot that looks like an excavator, while the robot that builds the habitat itself may look more like a 3D printer.
For a multi-functional robot that can do everything, the best approach may be to send humanoid robots such as NASA’s R5 (Valkyrie) that can grasp human tools while operating in harsh environments.
Xavier De Kestelier, head of design technology and innovation at Hassell, told B1M that sending one or two robots to Mars would be risky, as robotic failure would mean the end of the mission. Instead, he recommends sending loads of small robots that would work together on the same task.
“It’s like an ants’ nest: take half of the ants away, and the nest would still get built, but a bit slower,” he said. “It’s the same thing here – if not all of our robots arrive on Mars, [the habitat] would still get built – it would just take a bit longer.”
Building the Habitat
Most habitats are inflatable in design to minimize payload weight, but an inflatable dome offers little protection from the constant bombardment of ultraviolet radiation on the Martian surface. Therefore, many habitat designs involve an inflatable dome housed inside a thicker protective covering constructed from regolith.
In partnership with structural engineers Eckersley O’Callaghan, Hassell designed an external, cave-like shell that could be constructed entirely from regolith using autonomous robots equipped with cameras and sensors. Once the shell is constructed, the human mission can arrive with inflatable pods to be set up inside the cave structure, while the robots take on new roles such as scouting for new locations. The design was shortlisted for NASA’s international 3D Printed Habitat Challenge.
The winning entrant, AI SpaceFactory, designed a tall and slim habitat that would be built on a telescoping arm attached to a rover.
The now-abandoned plans for the Mars One project included a long-armed rover depositing Martian soil on top of the mission’s inflatable domes to protect them from radiation.
Other tasks that could be undertaken by robots before human arrival on Mars include:
Preparation of the landing ground for a crewed ship to touch down safely.
Construction of an automated processing plant to manufacture fuel (propellant), water, and oxygen.
Preparation of greenhouses or hydroponic chambers for growing enough food to support a human crew.
Drilling or hollowing out underground spaces for further protection from UV radiation.
Some of the hurdles to overcome include refining robotic construction techniques that require no human intervention, and working on ways to turn Martian regolith into a viable material for 3D printing.
It’s unlikely that a human mission will get to Mars before 2037, but before that point – two, five, or 10 years earlier – a team of robotic builders will cross the 33.9 million miles and get to work on making Mars habitable.