THE SPACESUITS
To walk on the Moon obviously requires a spacesuit – and these are not simple items of clothing. Spacesuits have constantly evolved to give astronauts the protection and the usability they need. For the Artemis Moon landings, those will have to be taken to a whole new level.
If you think of a spacesuit not as a garment, but as a flexible spacecraft that you wear, then you get closer to the complexity involved in making one. On top of that, it should hinder the astronaut’s movements as little as possible.
NASA is designing the eXploration Extravehicular Mobility Unit, or xEMU. A big issue for mobility in a spacesuit is the pressure of the air inside. When an astronaut bends a limb, it compresses the material and reduces the volume inside the suit, leading to an increase in air pressure that resists the motion of the astronaut.
Using bearings at the joints rather than compressible fabric helps address this issue. Whereas the Apollo spacesuits worn by Neil Armstrong and Buzz Aldrin on their trip to the Moon in 1969 used bearings only in the arms, the xEMU will use them in the arms, waist, hips, thighs and ankle joints. The suits will also let the astronauts vary the air pressure, allowing them to reduce it in order to kneel down.
All in all, the new innovations should provide far more flexibility for the astronauts and a much more comfortable environment in which to work. It should even allow them to walk more normally than the Apollo astronauts, who developed a kind of loping gait because of the low lunar gravity combined with the inflexibility of the spacesuit.