Header Bar Graphic
Space Image and IconSpace HeaderKids Image
Spacer Space IconHomepage ButtonWhat is NASA Quest ButtonSpacerCalendar of Events ButtonWhat is an Event ButtonHow do I Participate ButtonSpacerBios and Journals ButtonSpacerPics, Flicks and Facts ButtonArchived Events ButtonQ and A ButtonNews ButtonSpacerEducators and Parents ButtonSpacer
Highlight Graphic
Sitemap ButtonSearch ButtonContact Button

The Space Shuttle Extravehicular Mobility Unit (EMU)

As NASA changed from launching astronauts on expendable rockets to the Space Shuttle system with its reusable orbiter and solid rocket boosters, spacesuit engineers began development of a reusable EMU. Previously, all spacesuits were one-time garments. Spacesuits were custom-built to each astronaut’s body size. In the Apollo program, for example, each astronaut had three custom suits- one for flight, one for training, and one for flight backup. Shuttle suits, however, are tailored from a stock of standard-size parts to fit astronauts with a wide range of measurements.

In constructing the Shuttle spacesuit, designers were able to concentrate all their designs toward a single function- going EVA. Suits from earlier manned spaceflight programs had to serve multiple functions. They had to provide backup pressure in case of cabin pressure failure and, on Gemini missions, protection if ejection became necessary during launch. They also had to provide an environment for EVA in microgravity and in low gravity while walking on the Moon (Apollo missions). Suits were worn during lift off and reentry and had to be comfortable under the high-g forces experienced during acceleration and deceleration. Shuttle suits are worn only when it is time to venture outside the orbiter cabin. At other times, crew members wear comfortable shirts and slacks, or shorts. For launch and reentry, special orange-colored flight suits with helmets are worn.

drawing of EMU

Many Layers

The Shuttle EMU has 14 layers to protect astronauts on EVAs. The inner layers comprise the liquid-cooling-and-ventilation garment. First comes a liner of Nylon tricot over which is a layer of spandex fabric laced with plastic tubing. Next comes the pressure bladder layer of urethane-coated nylon and fabric layer of pressure-restraining Dacron®. Above the bladder and restraint layer is a liner of Neoprene coated Nylon Ripstop. This is followed by a seven-layer thermal micrometeoroid garment of aluminized Mylar®, laminated with Dacron® scrim. The outer layer of the suit is made of Ortho-Fabric which consists of a blend of Gortex®, Kevlar®, and Nomex® materials


2. Liquid Cooling and Ventilation Garment Liner Outer Layer (Nylon/Spandex)


1. Liquid Cooling and Ventilation Garment Liner (Nylon tricot)


14. Thermal Micrometeoroid Garment Cover (Ortho-Fabric)


3. Liquid Cooling and Ventilation Garment Liner Water Transport Tubing

drawing of insulation






7-13. Thermal Micrometeoroid Garment Liner (Multi-layered Insulation&endash;Aluminized Mylar®)

4.Pressure Garment Bladder (Urethane Coated Nylon)

5. Restraint (Dacron®)

6. Thermal Micrometeoroid Garment Liner (Neoprene Coated Nylong Ripstop)

 go to next page  /   return to contents


Footer Bar Graphic
SpacerSpace IconAerospace IconAstrobiology IconWomen of NASA IconSpacer
Footer Info