Dressed to kill: 50 years of the spacewalk

Abstract

The ISS has the equipment necessary to support controlled decompression. Future human missions to the moon or Mars, using smaller spacecraft, may have to dispense with it. Suits and ships alike will have to operate at the same pressure. The problem of ballooning will be overcome by a suit design that, at first glance, seems a retrograde development. NASA's latest prototype, known as the Z-suit, looks like an armoured robot from 1950s science fiction. Recent publicity photos show an astronaut wearing a white Z-suit uncannily like Buzz Lightyear's, but the outer fabric is a superficial layer of micrometeorite protection. Inside, there's a shell of hard composites tough enough to withstand contact with jagged rocks and abrasive surface dust on the moon and Mars. Whenever an astronaut on a planetary mission climbs out of a suit, there will be a danger of inhaling potentially toxic dust particles from outside the lander or habitat. The simple solution is to never expose astronauts to the suit's mucky exterior. Actually, this is easier than it sounds. The rear of the Z-suit features an airlock. When not in use, the entire thing is stored on the outside of a rover, docked to a 'suit portal'. Essentially a Z-suit is like a miniature spacecraft in its own right. Astronauts can swap at will between the suit and the airlock areas of a habitat or rover without waiting for the pressures to equalise. Ballooning is eliminated by pushing the rigidity of the suit to the logical extreme, until its fabric has no flexibility at all, except in the gloves and at the limb joints.