New Delhi: More than 50 years ago, humans first walked on the moon. Since then, several feats have been achieved in space exploration. Now NASA plans to send humans to the Moon again, via the Artemis mission.
Therefore, researchers are trying to design more advanced spacesuits and create a more suitable environment for astronauts during spacewalks.
Scientists at Texas A&M University in the United States are working on a new spacesuit architecture called “SmartSuit”. According to scientists, SmartSuit would create a safer and better spacesuit environment for extravehicular activity (EVA) on planetary surfaces.
The results of their research were recently published in the journal npj Microgravity, aerospace medicine and human performance.
What is SmartSuit?
The SmartSuit is a spacesuit architecture that focuses on three key improvements to the current suit design, namely increased mobility, increased safety and informed interaction between the environment and the astronaut, according to the study.
SmartSuit is offered by Ana Diaz Artiles, one of the authors of the study. Texas A&M researchers recently collaborated with Robert Shephard, an associate professor at Cornell University, to develop prototype soft robotic assist actuators for knee joints. An actuator is a device that produces motion by converting energy and signals entering the system. The movement can be rotary or linear.
How are current spacesuits designed?
In a statement released by Texas A&M University, Diaz Artiles said the current spacesuit was designed for microgravity conditions. She explained that in these conditions astronauts don’t need to walk or move using the lower body, they usually translate using the upper body.
Diaz Artiles added that when astronauts are on a planetary surface, they have to walk, bend, kneel, pick up rocks, and many other similar activities that require better lower body mobility.
How do Soft-Robotic knee prototypes work?
According to the study, flexible robotic knee prototypes work by using gas pressure to expand internal chambers, so they push against each other.
As each internal chamber expands, the actuator bends. By using soft material, the actuator adapts to the human body. This creates a more comfortable fit and potentially reduces the risk of injury.
Logan Kluis, the study’s lead author, said soft robotics would allow actuators to conform to the astronaut’s body. This would greatly increase their comfort compared to stiffer hard surface actuators.
Robotic Actuators Reduce Metabolic Costs
Astronauts wearing the current space suit feel like they are in a pressurized balloon. They have to fight against the suit, which is not only difficult, but also expends energy that they will want to conserve when conducting EVA missions. According to the study, the energy expended to move against the suit contributes to the metabolic cost. Assistive robotic actuators are able to reduce metabolic cost by 15%, according to simulations specifically developed to study the effects of these actuators.
Kluis said a lot of energy is expended when astronauts collect samples and perform tests. He said that when astronauts are sent on missions to the Moon and Mars, they will either have to take all the food with them or grow it. Therefore, any form of energy saving that can be achieved will be very helpful, he added.
How will a full layer help astronauts?
Recent work by scientists has focused on actuators for knee joints. However, their ultimate goal is to integrate actuators into a full body layer. This will improve the movement of several joints in the body, according to the study.
The full body layer would press relatively hard against the astronaut, providing additional mechanical counter pressure (MCP), which increases mobility.
In the late 1950s, NASA and the United States Air Force had developed a Mechanical Counter Pressure (MCP) suit that applied stable pressure against the skin by means of tight-fitting elastic garments. It was developed again in the late 1960s, but the designs were never used.
Diaz Artiles said pressure and mobility have an inverse relationship. The more pressure there is in a spacesuit, the lower the mobility. The less pressure an astronaut has, the easier it is to move.
The authors noted in the study that pressure refers to the gas pressure provided by the spacesuit to protect the wearer. Atmospheric pressure is about 14.7 pounds per square inch, and the current spacesuit provides a pressure of about 4.3 pounds per square inch, which pulsates against the astronaut’s body and contributes to the effect of ball. However, if a soft full-body robotic diaper could deliver one psi, it would reduce the amount needed for the suit to just 3.3 psi. This means there will be less pressure and more mobility.
Kluis said that when you wear very tight armor or very tight leggings, you feel extra pressure. The idea with the SmartSuit is that it would use both mechanical pressure and gas pressure.
What is decompression sickness?
Mechanical back pressure can reduce the risk of decompression sickness (DCS), which refers to injuries caused by a rapid decrease in air or water pressure surrounding a person. It can also happen when traveling in an unpressurized plane. When an astronaut steps into a spacesuit at low pressure, bubbles of inert gas form in human tissue. According to NASA, astronauts should take precautions to avoid decompression sickness that could occur during spacewalks.
According to the study, decompression sickness can occur when the gas pressure surrounding a person decreases relatively quickly, as a result of which nitrogen in the body emerges as bubbles inside body tissues.
Breathing pure oxygen for up to four hours before performing an EVA is the current solution to avoid spacesuit decompression sickness. With the implementation of mechanical back pressure, astronauts can spend less time on pre-breathing requirements and more time on space exploration. Plus, they won’t have to worry about decompression sickness.
According to the release, researchers are still working on the SpaceSuit architecture. The actuator prototypes will help create a more accommodating and resourceful spacesuit for future planetary missions.
The main goal of the researchers is to create a spacesuit that will make astronauts feel like they are moving around without a spacesuit.