The Mark III or MK III (H-1) is a

NASA The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the federal government of the United States, US federal government responsible for the United States ...

space suit A space suit (or spacesuit) is an environmental suit used for protection from the harsh environment of outer space, mainly from its vacuum as a highly specialized pressure suit, but also its temperature extremes, as well as radiation and ...

technology demonstrator built by

ILC Dover ILC Dover is a special engineering development and manufacturing company, globally headquartered in Frederica, Delaware. It specializes in the use of high-performance flexible materials, serving the aerospace manufacturer, aerospace, personal pr ...

. While heavier than other suits (at , with a Primary Life Support System backpack), the Mark III is more mobile, and is designed for a relatively high operating pressure. The Mark III is a rear-entry suit, unlike the

EMU The emu (; ''Dromaius novaehollandiae'') is a species of flightless bird endemism, endemic to Australia, where it is the Tallest extant birds, tallest native bird. It is the only extant taxon, extant member of the genus ''Dromaius'' and the ...

currently in use, which is a waist-entry suit. The suit incorporates a mix of hard and soft suit components, including hard upper torso, hard lower torso and hip elements made of

graphite Graphite () is a Crystallinity, crystalline allotrope (form) of the element carbon. It consists of many stacked Layered materials, layers of graphene, typically in excess of hundreds of layers. Graphite occurs naturally and is the most stable ...

epoxy Epoxy is the family of basic components or Curing (chemistry), cured end products of epoxy Resin, resins. Epoxy resins, also known as polyepoxides, are a class of reactive prepolymers and polymers which contain epoxide groups. The epoxide fun ...

composite Composite or compositing may refer to: Materials * Composite material, a material that is made from several different substances ** Metal matrix composite, composed of metal and other parts ** Cermet, a composite of ceramic and metallic material ...

, bearings at the shoulder, upper arm, hip, waist, and ankle, and soft fabric joints at the elbow, knee, and ankle. The Mark III was originally designed to an operating pressure, which would make the Mark III a "zero-prebreathe" suit. For a vehicle with a one atmosphere, mixed-gas environment, such as that on the

International Space Station The International Space Station (ISS) is a large space station that was Assembly of the International Space Station, assembled and is maintained in low Earth orbit by a collaboration of five space agencies and their contractors: NASA (United ...

, the suit could be donned and ready for an EVA within the normal donning and checkout period without risk of the bends, which can occur with rapid depressurization from an atmosphere containing

nitrogen Nitrogen is a chemical element; it has Symbol (chemistry), symbol N and atomic number 7. Nitrogen is a Nonmetal (chemistry), nonmetal and the lightest member of pnictogen, group 15 of the periodic table, often called the Pnictogen, pnictogens. ...

or another inert gas. Currently, ISS astronauts must spend several hours in a reduced pressure, pure

oxygen Oxygen is a chemical element; it has chemical symbol, symbol O and atomic number 8. It is a member of the chalcogen group (periodic table), group in the periodic table, a highly reactivity (chemistry), reactive nonmetal (chemistry), non ...

environment before EVA to avoid these risks.

Testing

The Mark III, as well as ILC's I-Suit, has been involved in field testing during NASA's annual Desert Research and Technology Studies (D-RATS) field trials, during which suit occupants interact with one another, and with rovers and other equipment. Subjects wearing the Mark III were able to kneel to pick up objects, a task which would be difficult in either the Apollo A7L or Shuttle

suit. Dean Eppler, a geologist at NASA's

Johnson Space Center The Lyndon B. Johnson Space Center (JSC) is NASA's center for human spaceflight in Houston, Texas (originally named the Manned Spacecraft Center), where human spaceflight training, research, and flight controller, flight control are conducted. ...

who wore the suit during testing, commented that "the Mark III in many cases has almost shirtsleeve-equivalent mobility." Eppler has spent more than 100 hours in the Mark III. As a result of the success of zero- and partial-gravity testing on the

KC-135 The Boeing KC-135 Stratotanker is an American military aerial refueling tanker aircraft that was developed from the Boeing 367-80 prototype, alongside the Boeing 707 airliner. It has a narrower fuselage and is shorter than the 707. Boeing gave ...

Vomit Comet A reduced-gravity aircraft is a type of fixed-wing aircraft that provides brief near-weightless environments for training astronauts, conducting research, and making gravity-free movie shots. Versions of such airplanes were operated by the NA ...

and in 1g field tests in Arizona and at Johnson Space Center, the EVA Project Office at Johnson Space Center is currently looking toward a soft suit design for future astronauts that incorporates the enhanced mobility features of the Mark III, but with a lower weight penalty. This new pressure garment design will provide greater surface mobility for planetary surface exploration than was available with the Apollo Program A7L and A7LB pressure garments.

References

{{space suit American spacesuits