Spacesuits have come a long way from their humble origins in the 1960s. But despite decades worth of innovation, the basic design remains the same – large, bulky, and limiting to the wearer’s range of movement. Hence why a number of researchers and scientists are looking to create suits that are snugger, more flexible, and more ergonomic. One such group hails from MIT, with a skin-tight design that’s sure to revolutionize the concept of spacesuits.
The team is led by Dava Newman, a professor of aeronautics and astronautics and engineering systems at MIT who previewed her Biosuit – playfully described by some as a “spidersuit” – at the TEDWomen event, held in San Fransisco in December of 2013. Referred to as a “second skin” suit, the design incorporates flexible, lightweight material that is lined with “tiny, muscle-like coils.”
Speaking of the challenges of spacesuit design, and her team’s new concept for one, Dava Newman had the following to say in an interview with MIT news:
With conventional spacesuits, you’re essentially in a balloon of gas that’s providing you with the necessary one-third of an atmosphere [of pressure,] to keep you alive in the vacuum of space. 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.
Granted, Newman’s design is the first form-fitting spacesuit concept to see the light of day. Back in the 1960’s, NASA began experimenting with a suit that was modeled on human skin, the result of which was the Space Activity Suit (SAS). Instead of an air-filled envelope, the SAS used a skin-tight rubber leotard that clung to astronaut like spandex, pressing in to protect the wearer from the vacuum of space by means of counter pressure.
For breathing, the suit had an inflatable bladder on the chest and the astronaut wore a simple helmet with an airtight ring seal to keep in pressure. This setup made for a much lighter, more flexible suit that was mechanically far simpler because the breathing system and a porous skin that removed the need for complex cooling systems. The snag with the SAS was that materials in the days of Apollo were much too primitive to make the design practical.
Little progress was made until Dava Newman and her team from MIT combined modern fabrics, computer modelling, and engineering techniques to produce the Biosuit. Though a far more practical counter-pressure suit than its predecessor, it was still plagued by one major drawback – the skintight apparatus was very difficult to put on. Solutions were proposed, such as a machine that would weave a new suit about the wearer when needed, but these were deemed impractical.
The new approach incorporates coils formed out of tightly packed, small-diameter springs made of a shape-memory alloy (SMA) into the suit fabric. Memory alloys are metals that can be bent or deformed, but when heated, return to their original shape. In this case, the nickel-titanium coils are formed into a tourniquet-like cuff that incorporates a length of heating wire. When a current is applied, the coil cinches up to provide the proper counter pressure needed for the Biosuit to work.
Bradley Holschuh, a post-doctorate in Newman’s lab, originally came up with the idea of a coil design. In the past, the big hurdle to second-skin spacesuits was how to get astronauts to squeeze in and out of the pressured, skintight suit. Holschuh’s breakthrough was to deploy shape-memory alloy as a technological end-around. To train the alloy, Holschuh wound raw SMA fiber into extremely tight coils and heated them to 450º C (842º F) to fashion an original or “trained” shape.
When the coil cooled to room temperature, it could be stretched out, but when heated to 60º C (140º F), it shrank back into its original shape in what the MIT team compared to a self-closing buckle. As spokespersons from MIT explained:
The researchers rigged an array of coils to an elastic cuff, attaching each coil to a small thread linked to the cuff. They then attached leads to the coils’ opposite ends and applied a voltage, generating heat. Between 60 and 160 C, the coils contracted, pulling the attached threads, and tightening the cuff.
In order to maintain it without continually heating the coils, however, the team needs to come up with some sort of a catch that will lock the coils in place rather than relying on a continuous supply of electricity and needlessly heating up the suit – yet it will still have to be easy to unfasten. Once Newman and her team find a solution to this problem, their suit could find other applications here on Earth.
As Holschuh explained, the applications for this technology go beyond the spacesuit, with applications ranging from the militarized to the medical. But for the moment, the intended purpose is keeping astronauts safe and comfortable:
You could [also] use this as a tourniquet system if someone is bleeding out on the battlefield. If your suit happens to have sensors, it could tourniquet you in the event of injury without you even having to think about it… An integrated suit is exciting to think about to enhance human performance. We’re trying to keep our astronauts alive, safe, and mobile, but these designs are not just for use in space.
Considering the ambitious plans NASA and other government and private space agencies have for the near-future – exploring Mars, mining asteroids, building a settlement on the Moon, etc. – a next-generation spacesuit would certainly come in handy. With new launch systems and space capsules being introduced for just this purpose, it only makes sense that the most basic pieces of equipment get a refit as well.
And be sure to check out this video of Dava Newman showing her Biosuit at the TEDWomen conference last year:
Sources: gizmag.com, motherboard.vice.com, newsoffice.mit.edu