Lift Off with SuperLimbs

As America plans its return to the moon after more than fifty years, a great many technological advancements will need to be made to ensure a successful mission. The most visible of these technologies are the rockets that will carry the crew to their destination a quarter of a million miles from Earth. This is unsurprising given how awe-inspiring the test launches of NASA’s Space Launch System and SpaceX’s Starship have proven to be.

But getting to the moon is only one small part of the equation. There are thousands of other considerations, and many unsung engineers are working around the clock to address them. Consider the challenges associated with getting around the moon after the astronauts arrive. The light gravity of the moon makes it very difficult for them to move about — if you need any convincing of that fact, look up some clips of previous moonwalks. They are fit to be on America's Funniest Home Videos.

Of course it is not all fun and games in reality. Those constant falls will take a toll on the space suit, so it must be rugged enough to withstand the abuse. Perhaps somewhat less obvious is the toll that it will take on the astronauts themselves. Frequently falling and having to get back up — in a bulky space suit, no less — is exhausting. Time is precious on a moon mission, so the crew needs to work fast. As such, this stumbling around is counterproductive to accomplishing the objectives of the mission.

MIT engineers have put forward a potential solution to this problem that would make Doctor Octopus proud. They have developed a backpack with what they call SuperLimbs, or robotic arms that can give astronauts a hand (literally) in getting back on their feet after a fall. The ultimate goal is to build SuperLimbs into the same backpack that carries an astronaut's life support system.

The SuperLimbs backpack contains motors to control the movements of a pair of multi-jointed robotic arms. When extended, the arms can support the weight of an astronaut. A controller was also built into the device to direct the movements of the robotic arms. The algorithm that drives this controller was designed after conducting experiments in which the team evaluated how people stand up from a lying position. This enabled them to define a series of waypoints that guide the process.

In a series of trials, volunteers were given bulky clothing somewhat like a space suit to wear and were outfitted with a SuperLimbs backpack. They were then asked to lie down on their back, front, or side, then try to stand up. The robotic system’s controller would determine the best way to provide assistance, and the robotic arms would then help them up. It was found that the volunteers could get back up with much less effort when SuperLimbs was providing help.

At present, the researchers are continuing to fine-tune their design and reduce its weight. They hope that one day their system might be used on a mission to the moon or Mars. Until then, they believe that it will also be useful right here on Earth, perhaps to assist workers in manufacturing or construction.