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

NASA The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeeding t ...

space suit A space suit or spacesuit is a garment worn to keep a human alive in the harsh environment of outer space, vacuum and temperature extremes. Space suits are often worn inside spacecraft as a safety precaution in case of loss of cabin pressure, ...

technology demonstrator built by

ILC Dover ILC Dover, LP is a special engineering development and manufacturing company, globally headquartered in Newark, Delaware. ILC Dover specializes in the use of high-performance flexible materials, serving the aerospace, personal protection, and p ...

. While heavier than other suits (at , with a

Primary Life Support System A primary (or portable or personal) life support system (or subsystem) (PLSS), is a device connected to an astronaut or cosmonaut's spacesuit, which allows extra-vehicular activity with maximum freedom, independent of a spacecraft's life support ...

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 the second-tallest living bird after its ratite relative the ostrich. It is endemic to Australia where it is the largest native bird and the only extant member of the genus ''Dromaius''. The emu' ...

currently in use, which is a waist-entry suit. The suit incorporates a mix of hard and soft suit components, including

hard upper torso A Hard Upper Torso Assembly, or HUT, is a central component of several space suits, notably Roscosmos' Orlan space suit, Orlan and NASA's Extravehicular Mobility Unit (EMU). The fiberglass HUT forms a rigid enclosure about the upper body of the o ...

, hard lower torso and hip elements made of

graphite Graphite () is a crystalline form of the element carbon. It consists of stacked layers of graphene. Graphite occurs naturally and is the most stable form of carbon under standard conditions. Synthetic and natural graphite are consumed on large ...

epoxy Epoxy is the family of basic components or cured end products of epoxy resins. Epoxy resins, also known as polyepoxides, are a class of reactive prepolymers and polymers which contain epoxide groups. The epoxide functional group is also coll ...

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 materials ...

, 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 the largest modular space station currently in low Earth orbit. It is a multinational collaborative project involving five participating space agencies: NASA (United States), Roscosmos (Russia), JAXA ...

, the suit could be donned and ready for an EVA within the normal donning and checkout period without risk of

the bends "The bends" is a colloquialism for decompression sickness. The Bends may also refer to: * ''The Bends'' (album), a 1995 studio album by Radiohead * "The Bends" (song), a 1995 song by Radiohead * "The Bends", a song by Mr. Bungle from the 1995 alb ...

, which can occur with rapid depressurization from an atmosphere containing

nitrogen Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at se ...

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

oxygen Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as wel ...

environment before

EVA Eva or EVA may refer to: * Eva (name), a feminine given name Arts, entertainment, and media Fictional characters * Eva (Dynamite Entertainment), a comic book character by Dynamite Entertainment * Eva (''Devil May Cry''), Dante's mother in t ...

to avoid these risks.

Testing

The Mark III, as well as ILC's

I-Suit The I-Suit is a spacesuit model constructed by ILC Dover. The suit began as an EVA mobility demonstrator, developed to meet a contract awarded by NASA to ILC in 1997 for an all-soft suit. The I-Suit is designed for multiple roles, including pl ...

, has been involved in field testing during NASA's annual

Desert Research and Technology Studies NASA's Desert Research and Technology Studies (Desert RATS or D-RATS) is a group of teams which perform an annual series of field trials seeking to demonstrate and test candidate technologies and systems for human exploration of the surface of th ...

(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 (originally named the Manned Spacecraft Center), where human spaceflight training, research, and flight control are conducted. It was renamed in honor of the late U ...

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 aircraft that was developed from the Boeing 367-80 prototype, alongside the Boeing 707 airliner. It is the predominant variant of the C-135 Stratolifter family of transpo ...

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 NAS ...

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