Robots to Build Underground Habitats on Mars

Although NASA has sent several rovers to Mars, they have yet to send humans. Why? Several reasons exist, like the need for improved transport to Mars and habitats for when humans do arrive. Researchers have released a report that says they can use swarms of robots to build underground habitats for humans. The habitats would allow surface exploration and protect from long-term radiation exposure.

Underground Habitats

The idea for humans to live subsurface is not new. Other researchers have developed concepts for living on the side of hills in caves. It’s getting to what will work best that drives plans for these habitats. The European Space Agency put forward grants for ideas on how to make underground habitats. Students at the Robotic Building lab (RB) at TU Delft focused on off-Earth construction resources. The students were led in their research by directed by Dr. Henriette Bier. They worked together with experts in material science, robotics, and aerospace engineering to create their proposal. The European Space Agency liked their idea and gave them a grant of €100k to develop a sample habitat.

Concept of a underground habitat and the robots and energy sources that will build and power it. Credit: Bier et al.

          Concept of an underground habitat and the robots and energy sources that will build and power it. Credit: Bier et al.

Regolith for Habitats

Utilizing the robotics lab, the proposal seeks to do the following.

1. Dig out the regolith, the dusty, pulverized rock layer deposited throughout the solar system over billions of years by asteroid collisions. “It’s a ready-made construction material. It’s crushed rock sitting on the surface of the planet,” says Robert P. Mueller. Mr. Meuller is the senior technologist for advanced products development at the Swamp Works, an innovation laboratory he cofounded at NASA’s Kennedy Space Center.
2. Print a new habitat using an additive manufacturing process. “All we have to do is develop the technology to use that aggregate that already exists and somehow bind that aggregate together.”  Mars regolith is mostly silicon dioxide and ferric oxide, with a fair amount of aluminum oxide, calcium oxide, and sulfur oxide.

Robots Digging and Creating

1. Coordinate the work between all the robots that would be needed to complete the tasks. Researchers state that the robots will excavate the ground in a sloped downwards spiral movement. Then, utilizing a “cement” mixture, the robots will spray that onto the cave walls they dug. In order to regulate the indoor pressurized environment, an inflatable structure is placed in the 3D printed cavity. This inflatable structure is made of materials, which can also be at some point reproduced on Mars.
2. Power the robots as well as the habitat. Will the lab utilize the same power technology that NASA uses for their Perseverance Rover? The rover uses a Radioisotope Thermoelectric Generator, which uses radioactive pellets to generate electricity. According to the report, they may utilize solar or kite power. The European Space Agency suggests using a giant kite flown by robots to harness high Martian wind speeds. They believe this could provide enough energy to sustain several astronauts in their everyday work.

All of these concepts lead to the same conclusion. Humans will live either in caves on the sides of hills or several meters below the Martian surface in the years of early exploration. However they achieve their goals, let us hope their structures will keep humans safe.