Looking for a good laugh? Watching videos of astronauts stumbling on the moon provides endless entertainment. NASA’s outtakes showcase Apollo astronauts bouncing and tumbling in slow motion, reminding us just how relatable these high-flying heroes can be.
But for engineering minds at MIT, these lunar mishaps are more than just amusing; they present a unique opportunity for innovation.
“Astronauts have remarkable physical abilities, yet they still face challenges on the moon where gravity is only one-sixth of Earth’s, while their inertia remains unaltered. Furthermore, the constraints of spacesuits significantly limit their movements,” explains Harry Asada, a mechanical engineering professor at MIT. “Our goal is to provide a safe mechanism for astronauts to regain their footing after a fall.”
Asada and his team are developing wearable robotic limbs designed to support astronauts and help them stand up after a fall. Dubbed Supernumerary Robotic Limbs, or “SuperLimbs,” this system would deploy from a backpack carrying both an astronaut’s life support equipment and the controls needed to operate the device.
The engineering team has crafted a physical prototype along with a control system that responds to the astronaut’s feedback. Preliminary tests were conducted using healthy participants wearing a suit similar to a constrictive spacesuit. These volunteers found it significantly easier to rise from a sitting or lying position when assisted by SuperLimbs compared to trying to recover independently.
The MIT team envisions that SuperLimbs will not only aid astronauts who fall but will also help them conserve energy for vital tasks. This innovation is particularly timely, with NASA’s Artemis mission set to return astronauts to the moon for the first time in over 50 years. Unlike the primarily exploratory Apollo missions, Artemis aims to establish a permanent lunar base—a task requiring extensive extravehicular activities (EVAs) that will be physically demanding.
Asada, Ballesteros, and their team will showcase their research this week at the IEEE International Conference on Robotics and Automation (ICRA). They are joined by MIT postdoc Sang-Yoep Lee and Kalind Carpenter from the Jet Propulsion Laboratory.
A New Approach to Recovery
This latest application of SuperLimbs marks a significant evolution of a technology Asada initiated nearly a decade ago. Originally designed to assist workers in fields like aircraft manufacturing and construction, the concept is now being tailored for the challenges faced by astronauts.
“In discussions with NASA, we discovered that falling on the moon poses a serious threat to astronaut safety,” says Asada. “We recognized the potential to modify our design to assist astronauts in recovery.”
The team began by analyzing how humans naturally recover from falls. They tasked healthy volunteers with standing up after lying in various positions. To simulate the restricted movement of a spacesuit, the researchers constructed a suit that mimicked the rigidity of traditional spacesuits. They had participants wear it and repeat their attempts to stand.
The analysis revealed a consistent sequence of movements across most individuals when rising from the ground, highlighting that around 80 percent of people follow a similar standing pattern. This understanding allowed the team to design a control system that mirrors these movements.
Technology in Action
The team developed software that generates a trajectory for a robot to support a human during recovery. They tested this controller with a heavy, stationary robotic arm attached to a backpack, designed to help participants stand when they attempted to get up while wearing a bulky suit.
Results showed that participants could achieve a stable standing position with significantly less effort with the robot’s assistance compared to standing unaided in the suit.
“It’s like having an extra force guiding you up,” shares Ballesteros, who experienced the suit and arm assist firsthand. “Imagine wearing a backpack and having someone gently pull you up. It quickly begins to feel instinctive.”
These experiments validated that the robotic system can efficiently assist individuals in standing after a fall. The researchers plan to integrate this control system with the newest iteration of SuperLimbs, comprising two multi-jointed robotic arms that extend from a backpack that also houses the battery, motors, and astronaut ventilation system.
“We engineered these robotic arms using an AI-driven search and design optimization process to create efficient designs under specific engineering constraints,” explains Ballesteros. “We explored numerous designs, ultimately identifying the one that consumes the least energy while aiding a person to stand.”
This summer, Ballesteros will finalize the SuperLimbs system at NASA’s Jet Propulsion Laboratory, aiming to optimize its design and reduce the weight of components using advanced materials. His goal is to couple the limbs with space suits and test them in low-gravity environments, paving the way to assist astronauts on future moon and Mars missions.
“Spacesuits can create a physical load on astronauts,” notes Asada. “Implementing robotic systems could alleviate this burden, empowering astronauts to maximize their productivity during missions.”
This groundbreaking research has received partial support from NASA.
Photo credit & article inspired by: Massachusetts Institute of Technology
