Research Explainer

by Dennis Meredith, author, Earthbound: The Obstacles to Human Space Exploration and the Promise of Artificial Intelligence.

Reprinted from SpaceNews

When the Artemis astronauts step onto the lunar surface, they will have spent considerable time and effort installing themselves in their bulky, heavy spacesuits. They will lumber onto the surface having limited mobility and time, struggling to accomplish their assigned tasks. Their activities will kick up clinging, razor-sharp lunar dust that they will invariably carry back into their capsule on their suits. And they will enter that capsule exhausted, perhaps even injured.

Even as bulky and uncomfortable as they are, these spacesuits, the modern-day equivalent of the massive medieval armor, required many years and billions of dollars to develop. And even then, they will have had to undergo extensive re-engineering to adapt the early design for the lunar surface.

But what if astronauts didn’t even have to don spacesuits to explore the lunar or Martian surface? While the Artemis astronauts will be required to use spacesuits, future astronauts need not be. Why couldn’t they instead carry out their missions using remotely operated vehicles (ROVs) fitted with cameras and manipulators? Or, for longer forays across the lunar and Martian terrain, why couldn’t they explore ensconced in mobile habitats (MoHabs), operating attached manipulators?

Former astronauts who have done spacewalks and studied the Artemis spacesuits don’t have much good to say about them. In a  presentation to the National Academies, former astronaut Kate Rubin said, “When we get to the lunar surface, people are going to be sleep shifting. They’re barely going to get any sleep. They’re going to be in these suits for eight or nine hours. They’re going to be doing EVAs every day. The EVAs that I did on my flights, it was like doing a marathon and then doing another marathon when you were done.”

She added, “I think the suits are better than Apollo, but I don’t think they are great right now. . . . They still have a lot of flexibility issues. Bending down to pick up rocks is hard. The center of gravity is an issue. People are going to be falling over. I think when we say these suits aren’t bad, it’s because the suits have been so horrible that when we get something slightly less than horrible, we get all excited and we celebrate.”

Mike Barratt, a NASA astronaut and medical doctor, said that EVA suit accommodation has resulted in “everything from skin abrasions to joint pain to—no kidding—orthopedic trauma. You can potentially get a fracture of sorts. EVAs on the lunar surface with a heavily loaded suit and heavy loads that you’re either carrying or tools that you’re reacting against, that’s an issue.”

Astronauts would be more productive if they didn’t have to spend time donning, doffing, cleaning, and servicing spacesuits. They would experience less fatigue and a lower risk of injuries if they spent their exploration time in a comfortable shirtsleeve environment. Less energy expended would mean lower consumption of oxygen, water, and food.

Their explorations and other operations would be safer. There would be lower risk of malfunction due to the complexity of the suits. And AI could enable the ROVs and MoHabs to automatically navigate the safest terrain far more effectively than could an astronaut encased in a suit.

Astronauts would be arguably healthier because exposure to lunar dust would be all but eliminated. Apollo astronauts all developed “lunar hay fever” from the dust, even on their short missions. They were assailed by the dust’s cloying smell they described as like burnt gunpowder. Imagine how much more toxic dust exposure would be on long missions. A report on the lung effects of lunar dust concluded that, “The combination of altered pulmonary deposition of extraterrestrial dust and the potential for the dust to be highly toxic likely makes dust exposure the greatest threat to the lung in planetary exploration.^”

All these advantages would likely engender a higher morale among astronauts confined to surface habitats for long periods.

Technologies to create lunar ROVs and MoHabs either already exist or are on the drawing board. NASA plans to develop a pressurized rover for extended exploration. Such a rover, fitted with manipulators, could be accessible through an airlock and serviced via built-in connectors.

For decades, ocean explorers and engineers have used underwater ROVs fitted with dexterous manipulators to carry out their missions. And manipulators such as those used in robotic surgery can perform even the finest procedures. Such control technologies would seem to be adaptable to lunar and Martian exploration.

Engineers could also go beyond the traditional wheeled vehicles in creating such systems. For example, agile, legged robots could provide the basis for an ROV or even MoHab that could traverse terrain inaccessible by wheeled vehicles. To that end, NASA’s Jet Propulsion Laboratory and Boston Dynamics are developing the legged robot NeBula-SPOT for such a role. One can envision future astronauts guiding such a legged ROV or even riding in a legged MoHab down a precariously steep slope not traversable by a wheeled vehicle into a lunar crater.