A new spacesuit being designed as the latest in astronaut wear has a new wrinkle, its designers say; it will effectively "shrink wrap" its wearer in what amounts to a second skin.
Researchers at the Massachusetts Institute of Technology say their BioSuit design suit could not only offer support for an astronaut but would provide considerably more freedom of movement for planetary exploration than current gas-pressurized space suits.
Instead of gas pressure, BioSuit would act like a compression garment, with mechanical pressure created by coils containing metal wire that contract when heat is applied, taking advantage of so-called memory alloys that assume a particular shape when they are heated.
"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," says MIT aeronautics and engineering Professor Dava Newman. "We want to achieve that same pressurization, but through mechanical counterpressure -- applying the pressure directly to the skin, thus avoiding the gas pressure altogether."
When cool, she says, the suit would remain loose and flexible, allowing an astronaut to easily don it, then a small amount of heart could tighten the suit, ready for a spacewalk, for example.
Beyond just spacewalking, the technology could provide a lightweight, mobile suit better "suited" for planetary exploration, the researchers say.
At the heart of the suit's "shrinking" ability are coils of a nickel-titanium alloy configured as small-diameter, tightly-packed springs which contract when heated with a significant force compared to their slight mass, they say.
"These are basically self-closing buckles," says MIT postdoctoral researcher Bradley Holschuh, who created the coil design. "Once you put the suit on, you can run a current through all these little features, and the suit will shrink-wrap you, and pull closed."
That does raise one issue the researchers are dealing with: how to keep the suit's coils heated during the period of time it is worn.
Applying constant heat would likely require some bulky batteries, which would cut down on an astronaut's mobility, and the suit might get uncomfortably warm after a long period of wear.
That has led Newman and Holschuh to consider another alternative: finding a way to lock the coils in their tightened position once heated so that constant heating beyond the initial application would not be necessary.
There are possible applications for the technology beyond astronaut suits, they add, for instance in military uniforms.
"You could use this as a tourniquet system if someone is bleeding out on the battlefield," Holschuh says. "If your suit happens to have sensors, it could tourniquet you in the event of injury without you even having to think about it."
