Mark III (space suit)
Encyclopedia
The Mark III or MK III (H-1) is a NASA
space suit
technology demonstrator built by ILC Dover
. While heavier than other suits (at 59 kilograms (130.1 lb), with a 15 kilograms (33.1 lb) 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
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
/epoxy
composite
, bearing
s at the shoulder, upper arm, hip, waist, and ankle, and soft fabric joints at the elbow, knee, and ankle.
The 8.3 pound per square inches (57.2 kPa) operating pressure of the Mark III makes it a "zero-prebreathe" suit, meaning that astronauts would be able to transition directly from a one atmosphere, mixed-gas space station environment, such as that on the International Space Station
, to the suit, without risk of the bends
, which can occur with rapid depressurization from an atmosphere containing nitrogen
or another inert
gas. Currently, astronaut
s must spend several hours in a reduced pressure, pure oxygen
environment before EVA to avoid these risks.
, 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 EMU
suit. Dean Eppler, a geologist at NASA's Johnson Space Center 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.
Despite the success of zero- and partial-gravity testing on the KC-135 Vomit Comet
, the EVA Project Office at Johnson Space Center is currently looking toward a soft suit design for future astronauts.
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...
space suit
Space suit
A space suit is a garment worn to keep an astronaut alive in the harsh environment of outer space. Space suits are often worn inside spacecraft as a safety precaution in case of loss of cabin pressure, and are necessary for extra-vehicular activity , work done outside spacecraft...
technology demonstrator built by ILC Dover
ILC Dover
ILC Dover, LP is an engineering development and manufacturing company based in Frederica, Delaware. ILC specializes in the use of high-performance flexible materials, serving the aerospace, personal protection, and pharmaceutical industries.Best known for making space suits for NASA, ILC...
. While heavier than other suits (at 59 kilograms (130.1 lb), with a 15 kilograms (33.1 lb) Primary Life Support System
Primary Life Support System
A Primary Life Support System , is a device connected to an astronaut's or cosmonaut's spacesuit, which allows extra-vehicular activity with maximum freedom, independent of a spacecraft's life support system. The PLSS is generally worn like a backpack...
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
Extravehicular Mobility Unit
The Space Shuttle/International Space Station Extravehicular Mobility Unit is an independent anthropomorphic system that provides environmental protection, mobility, life support, and communications for a Space Shuttle or International Space Station crew member to perform extra-vehicular activity...
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 Upper Torso
A Hard Upper Torso Assembly, or HUT, is a central component of several space suits, notably Roscosmos' Orlan and NASA's Extravehicular Mobility Unit . The fiberglass HUT forms a rigid enclosure about the upper body of the occupant, providing pressure containment for this part of the body...
, hard lower torso and hip elements made of graphite
Graphite
The mineral graphite is one of the allotropes of carbon. It was named by Abraham Gottlob Werner in 1789 from the Ancient Greek γράφω , "to draw/write", for its use in pencils, where it is commonly called lead . Unlike diamond , graphite is an electrical conductor, a semimetal...
/epoxy
Epoxy
Epoxy, also known as polyepoxide, is a thermosetting polymer formed from reaction of an epoxide "resin" with polyamine "hardener". Epoxy has a wide range of applications, including fiber-reinforced plastic materials and general purpose adhesives....
composite
Composite material
Composite materials, often shortened to composites or called composition materials, are engineered or naturally occurring materials made from two or more constituent materials with significantly different physical or chemical properties which remain separate and distinct at the macroscopic or...
, bearing
Bearing (mechanical)
A bearing is a device to allow constrained relative motion between two or more parts, typically rotation or linear movement. Bearings may be classified broadly according to the motions they allow and according to their principle of operation as well as by the directions of applied loads they can...
s at the shoulder, upper arm, hip, waist, and ankle, and soft fabric joints at the elbow, knee, and ankle.
The 8.3 pound per square inches (57.2 kPa) operating pressure of the Mark III makes it a "zero-prebreathe" suit, meaning that astronauts would be able to transition directly from a one atmosphere, mixed-gas space station environment, such as that on the International Space Station
International Space Station
The International Space Station is a habitable, artificial satellite in low Earth orbit. The ISS follows the Salyut, Almaz, Cosmos, Skylab, and Mir space stations, as the 11th space station launched, not including the Genesis I and II prototypes...
, to the suit, without risk of the bends
Decompression sickness
Decompression sickness describes a condition arising from dissolved gases coming out of solution into bubbles inside the body on depressurization...
, which can occur with rapid depressurization from an atmosphere containing nitrogen
Nitrogen
Nitrogen is a chemical element that has the symbol N, atomic number of 7 and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless, and mostly inert diatomic gas at standard conditions, constituting 78.08% by volume of Earth's atmosphere...
or another inert
Inert
-Chemistry:In chemistry, the term inert is used to describe a substance that is not chemically reactive.The noble gases were previously known as inert gases because of their perceived lack of participation in any chemical reactions...
gas. Currently, astronaut
Astronaut
An astronaut or cosmonaut is a person trained by a human spaceflight program to command, pilot, or serve as a crew member of a spacecraft....
s must spend several hours in a reduced pressure, pure oxygen
Oxygen
Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...
environment before EVA to avoid these risks.
Testing
The Mark III, as well as ILC's I-SuitI-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....
, has been involved in field testing during NASA's annual Desert Research and Technology Studies
Desert Research and Technology Studies
NASA's Desert Research and Technology Studies is a group of teams which perform an annual series of field trials seeking to demonstrate and test candidate technologies and systems for manned exploration of the surface of the Moon, Mars, or other rocky bodies.Desert RATS began in 1997, reviving...
(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
Apollo/Skylab A7L
The A7L Apollo & Skylab spacesuit is the primary pressure suit worn by NASA astronauts for Project Apollo, the three manned Skylab flights, and the Apollo-Soyuz Test Project between 1968 and the termination of the Apollo program in 1975. The "A7L" designation is used by NASA as the seventh Apollo...
or Shuttle EMU
Extravehicular Mobility Unit
The Space Shuttle/International Space Station Extravehicular Mobility Unit is an independent anthropomorphic system that provides environmental protection, mobility, life support, and communications for a Space Shuttle or International Space Station crew member to perform extra-vehicular activity...
suit. Dean Eppler, a geologist at NASA's Johnson Space Center 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.
Despite the success of zero- and partial-gravity testing on the KC-135 Vomit Comet
Vomit Comet
A Reduced Gravity Aircraft is a type of fixed-wing aircraft that briefly provides a nearly weightless environment in which to train astronauts, conduct research and film motion pictures....
, the EVA Project Office at Johnson Space Center is currently looking toward a soft suit design for future astronauts.