MIT researchers are developing a "second skin" space suit lined with tiny coils that contract when switched on, tightening the garment around the body.
The coils (image below) in the "BioSuit" are made from shape-memory alloy that "remembers" its shape when bent and returns to its original form if 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 Dava Newman, MIT professor of aeronautics and astronautics and engineering . “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."
"Shrink-wrapping spacesuits" (MIT)