The Future of Spacesuits – Biosuits with Memory
It’s official, we have a Mars mission in sight. NASA is making provisional plans to send humans on an exploration mission to one of the most notable planets in our solar system. By 2030 we may be answering some of the most fundamental scientific questions that have puzzled all of humankind, and start to put into perspective some of the calamities our planet has outmanoeuvred to be able to sustain all of life as we know it.
But, before we can start to answer those questions we will need to figure out how to get them there. The vast emptiness of space takes its toll on the human body, without the warm blanket that Earth’s atmosphere provides, the human body will ultimately perish. The best answer to this problem has always been to take a part of that atmosphere with you, and recreate the effects of Earth in the form of a pressurised suit.
Over the course of some 500 extravehicular activities – spacewalks, that is – most have been performed in the Extravehicular Mobility Unit (EMU pictured right). This is a remarkable bit of kit, coming in at $10 million, it is the smallest spacecraft in the world. The suit is designed to provide everything you will need to survive the harsh void of open space, from temperature control to scrubbing CO2, it even comes fitted with an adult-sized diaper, and is pressurised to one third of Earth’s atmosphere (33.77 kPa). However, the one main drawback to this design has always been mobility. The suit weighs in at around 140kg (308lb), no ordeal when you are in zero-gravity, but a major issue when you wish to explore the planet surface – lots of astronauts return from space missions that have involved EVA’s with damaged shoulders and other ligaments that have come under prolonged strain whilst in an EMU.
So a 3 to 4 year mission to Mars which could contain double the amount of all EVA’s ever conducted in space combined, needs to be more flexible, durable and practical than ever before – and it seems there may be a suitor. Lead researcher, Dava Newman the Professor of Aeronautics and Astronautics and Engineering Systems at MIT, has devoted the past decade to designing the next-generation spacesuit and describes the garment in detail within the Musculoskeletal Human-Spacesuit Interaction Model journal.
Newman’s Biosuit is following on from the work of Arthur Iberall, who developed the concept of lines of non-extension during the 1940’s, these lines denote the areas of the human body along which any body movement causes neither stretching nor contraction. Along these lines are coils of shape-memory alloys, which when a specific temperature is applied, will remember their engineered shape and spring back – and that is how you can produce the same one third of atmosphere of pressure without using an atmosphere.
We want to achieve that same pressurization, but through mechanical counterpressure – applying the pressure directly to the skin, thus avoiding the gas pressure altogether. We combine passive elastics with active materials. … Ultimately, the big advantage is mobility, and a very lightweight suit for planetary exploration.
The trouble with these suits has always been, what the procedurally minded like to call, donning and doffing – that is, getting in and out of the thing. Applying a third of the atmospheric pressure makes any garment a very tight squeeze, even though it is possible to squeeze into such an extraordinary suit, the effort required would most definitely need the hand of a couple of wardrobe assistants – a luxury lost in deep space. This is where the use of shape-memory alloys comes in, as the suit can be donned on loose and then an electric current can be passed through the coils to cause them to snap back into the remembered shape.
This sort of technology has a lot more potential than just recreating atmospheric pressure. Disregarding the lines of non-extension, the use of compression has lots of lifesaving applications within the military and medical profession.
If your suit happens to have sensors, it could tourniquet you in the event of injury without you even having to think about it.
With more research this sort of technology could help people with motor function disorders, like cerebral palsy, to help sufferers learn to walk at a very early age. That sort of thinking is currently in its infancy, but if the same significance of lines of non-extension are practised – where a co-operative force is applied upon the posture, to support the person – then the brain may be able to learn how to move the body with greater ease and increase the quality of life for everyone.