A mix-and-match kit could allow astronauts to build a collection of lunar exploration bots
By Jennifer Chu | MIT News Agency
When astronauts start building a permanent base on the moon, as NASA plans to do in the coming years, they will need help. Robots have the potential to do the heavy lifting by laying cables, installing solar panels, erecting communication towers and constructing habitats. But if each robot is designed for a specific action or task, the moon base could be overrun by a zoo of machines, each with their own unique parts and protocols.
To avoid bot jams, a team of MIT engineers is devising a universal robot parts kit that astronauts can easily mix and match to quickly configure different “species” of robots to suit various missions on the moon. Once a mission is completed, the robot can be disassembled and the parts used to configure a new robot to fulfill a different task.
The team calls the system WORMS, for the Walking Oligomer Robot Mobility System. The system parts include worm-inspired robotic limbs that astronauts can easily attach to the base, and which work together as a walking robot. Depending on the mission, parts can be configured to create, for example, large “package” bots capable of carrying heavy solar panels up hills. Those same parts can be reconfigured into a six-legged spider bot that can be lowered into a lava tube to drill into frozen water.
“You can imagine a warehouse on the moon with shelves of worms,” said team leader George Lordos, a PhD candidate and graduate instructor in MIT’s Department of Aeronautics and Astronautics (AeroAstro), referring to the independently articulated robots that carry their own robots. motors, sensors, computers, and batteries. “Astronauts can go into the storeroom, pick up the worms they need, along with the proper boots, bodies, sensors, and equipment, and they can put it all together, then take it apart to make new ones. The design is flexible, sustainable and cost effective.”
The Lordos team has built and demonstrated the six-legged WORMS robot. Last week, they presented their results at the IEEE’s Aerospace Conference, where they also received the Best Paper Award at the conference.
MIT team members include Michael J. Brown, Kir Latyshev, Aileen Liao, Sharmi Shah, Cesar Meza, Brooke Bensche, Cynthia Cao, Yang Chen, Alex S. Miller, Aditya Mehrotra, Jacob Rodriguez, Anna Mokkapati, Tomas Cantu, Katherina Sapozhnikov, Jessica Rutledge, David Trumper, Sangbae Kim, Olivier de Weck, Jeffrey Hoffman, along with Aleks Siemenn, Cormac O’Neill, Diego Rivero, Fiona Lin, Hanfei Cui, Isabella Golemme, John Zhang, Jolie Bercow, Prajwal Mahesh, Stephanie Howe, and Zeyad Al Awwad, as well as Chiara Rissola of Carnegie Mellon University and Wendell Chun of the University of Denver.
WORMS was conceived in 2022 in response to NASA’s Breakthrough, Innovative and Game-changing (BIG) Ideas Challenge — an annual competition for college students to design, develop, and demonstrate game-changing ideas. In 2022, NASA is challenging students to develop a robotic system that can move across extreme terrain, without the use of wheels.
The team from MIT Space Resources Workshop take on the challenge, which is dedicated specifically to the design of a lunar robot capable of navigating the extreme terrain of the lunar South Pole — a landscape characterized by thick and fine dust; steep and rocky slopes; and deep lava tubes. The environment also hosts “permanent shadow” areas that can contain frozen water, which if accessible would be critical to sustaining astronauts.
As they figure out how to navigate the moon’s polar terrain, students draw inspiration from animals. In their initial brainstorming, they noted certain animals could conceptually be suited for certain missions: A spider could descend and explore a lava tube, a line of elephants could carry heavy equipment while supporting each other down a steep slope, and a goat, tethered to an ox, could help get larger animals up the hillside while transporting a series of solar panels.
“When we thought about these animal inspirations, we realized that one of the simplest animals, worms, perform movements similar to arms, or legs, or spine, or tail,” said co-lead team leader and AeroAstro graduate student Michael Brown. “And then the light bulb went out: We can build all these animal-inspired robots using worm-like appendages.’”
Lordos, who is of Greek descent, helped create WORMS coins, and chose the letter “O” to stand for “oligomer”, which is Greek for “several parts”.
“Our idea was, with just a few pieces, put together in different ways, you can mix and match and get all these different robots,” said AeroAstro scholar Brooke Bensche.
The main body of the system includes an appendage, or worm, which can be attached to the body, or chassis, via a “universal interface block” that holds the two halves together via a turn-and-lock mechanism. The parts can be removed with a small tool which removes the spring block pins.
Attachments and bodies can also be incorporated into accessories such as a “shoe”, which the team engineered in the shape of a frying pan, and a LiDAR system that can map the environment to aid the robot’s navigation.
“In future iterations, we hope to add more snap-on sensors and tools, such as cranes, balance sensors, and drills,” said AeroAstro scholar Jacob Rodriguez.
The team developed scalable software to coordinate multiple complements. As a proof of concept, the team built a six-legged robot the size of a go-cart. In the lab, they demonstrated that once assembled, the autonomous robotic limbs worked to walk on level ground. The team also demonstrated that they could quickly assemble and disassemble the robot in the field, in a desert location in California.
In its first generation, each WORMS frill was about 1 meter long and weighed about 20 pounds. In the moon’s gravity, which is roughly one-sixth of Earth’s gravity, each limb would weigh about 3 pounds, which an astronaut could easily handle building or disassembling a robot in the field. The team has planned the specs for a larger generation with longer and slightly heavier appendages. These larger parts can be joined together to make a “package” boat, which is capable of hauling heavy loads.
“There are many popular terms used to describe effective systems for future space exploration: modular, reconfigurable, scalable, flexible, cross-cutting, etc,” said Kevin Kempton, an engineer at NASA’s Langley Research Center. , who served as a judge for the 2022 Big Idea Challenge. “The MIT WORMS concept incorporates all of these qualities and more.”
This research was supported in part by NASA, MIT, the Massachusetts Space Grant, the National Science Foundation, and the Fannie and John Hertz Foundation.