3 minute read
Astronaut suits
SPACE
Advertisement
Inside a spacesuit
What’s so special about an astronaut’s outfi t that it can keep them alive in space?
It’sprobablybesttothinkofa spacesuit not as an item of clothing – like a jumper you’d put on when it’s cold or a pair of wellies to keep your feet dry – but as a habitat or a small personal spaceship astronauts wear. Two of the main threats to human life in space are the lack of oxygen and the extreme range of temperatures, which can fl uctuate from below -100 degrees Celsius (-150 degrees Fahrenheit) to in excess of 120 degrees Celsius (242 degrees Fahrenheit). But they can face other dangers, too: the extremely low pressure, micrometeorites travelling several times the speed of a bullet and exposure to high levels of radiation, unfi ltered by any planetary atmosphere like Earth’s, travelling from the Sun and deep space.
Astronauts need protection from these dangers while on an extravehicular activity (EVA) in space, so the modern spacesuit is designed to do just that. The outer section is divided into several main pieces with fl exible and rigid parts, designed to provide mechanical protection from impact and a pressurised, oxygenated environment within the suit.
Underneath that, the astronaut wears a garment that helps regulate their body temperature with tubes that are woven into it, inside which water circulates for cooling. The astronaut’s chunky backpack carries the primary life support subsystem, which pumps the oxygen into the astronaut’s helmet for them to breathe and ‘scrubs’ the excess carbon dioxide out of the air they exhale. It also holds the electricity supply required to run the suit’s systems and a water tankforthecoolingsystem.
Extravehicular Mobility Unit
The space suit born in 1981 is still used outside the ISS today
Heavyweight
Acomplete EMU weighs over 100kg (220lb) but fortunately, the microgravity of space makes this feel nowhere near as much.
Gold layer
An astronaut’s visor is covered with a thin layer of gold, which is transparent but fi lters out harmful rays from the Sun.
Protection
A Hard Upper Torso (HUT) assembly provides a rigid base for the rest of the EMU to connect to and some protection from micrometeoroids.
Undergarments
Underneath the spacesuit, are Urine Collection Devices (UCDs) and a series of tubes that assist in cooling the astronaut.
The Z-suit
NASA’s prototype Z-suit is a work in progress on an update to the current incarnation of the spacesuit, whose basic structure has been used for 30 years, ever since the Extravehicular Mobility Unit (EMU) was fi rst made in 1981. At a glance, it doesn’t look radically different to contemporary space suits, but it’s been designed to include several key features that will allow it to be used in both the microgravity of space and for future missions to planets such as Mars, which the Apollo-era spacesuit isn’t capable of. It canbe quickly put on and taken off (current spacesuits can take an hour or more to puton) and include a suitport dock, which replaces the airlock on a spacecraft. This means the spacecraft and space suit would be kept atthe same pressure, so astronauts wouldn’t need to pre-breathe oxygen for at least 30 minutes before an EVA as they do now to prevent decompression sickness. The Z-2 prototype should be completed by the end of 2014.
Life support
The heavy backpack contains power for the spacesuit, air and a water tank for cooling.
Control module
The Display and Control Module gives the astronaut easy access to suit controls and communication.
Jetpacks
Astronauts only use jetpacks in emergencies. The Manned Manouvering Unit (MMU) shown here was replaced by the Simplifi ed Aid for EVA Rescue (SAFER) system in 1994.
