B. F. Goodrich made a full pressure suit for pioneering aviator Wiley Post. It was of double ply rubberized parachute fabric, with pigskin gloves, rubber boots, and aluminium helmet, pressurized to 0.5 bar. The pressure suit used a liquid oxygen source and had arm and leg joints that permitted easy operation of the flight controls and also enabled walking to and from the aircraft. In his Lockheed Vega, the "Winnie May", Post set unofficial altitude records (as high as 15 km), discovering the jet stream in the process. In March 1935, Post flew from Burbank California to Cleveland Ohio in the stratosphere using the jet stream. At times, his ground speed exceeded 550 kph in a 290 kph aircraft. Post's pioneering accomplishments were the first major practical advance in pressurised flight. Ten flights were made in the suit before Post's death in 1935.

The Germans designed a full pressure suit of laminated silk and rubber, with a reinforced net of silk cord. Several models were covered with a metallic outer covering to prevent ballooning. Suit pressures of 0.75 bar were achieved without 'sacrificing mobility', but the suit was very heavy. By the end of the war suits were in use with separate oxygen breathing and suit gas systems.

The first Italian pressure suit was used during 1934/37 by the "Regia Aeronautica" (Royal Air Force) to break altitude records with the Caproni 161, 161bis and 113 aircraft. The suit was made of several layers of canvas and rubber, with a metal collar to fit a cylindrical metal helmet with square view ports. The suit was worn by Colonel Mario Pezzi and Countess Carina Negroni in their attempts to reach altitudes over 6,000 m. The Italian suit was worn on a record altitude flight to 15,500 m in 1937.

As England continued its work with derivatives of the Ridge-Haldane-Davis suit, in the United States the US Army finally recognized, albeit somewhat belatedly, the potential importance of a fully pressurized protective garment for military aviators and started a classified research program in 1939, designated Project MX-117. Soon several US companies had been drawn into pressure suit developmental investigations; these included the B.F.Goodrich Company (Russell Colley's engineering group), Bell Aircraft Company, the Goodyear Rubber Company, the US Rubber Company, and the National Carbon Company. From 1940 through 1943 a number of original designs were produced. Generally speaking, they uniformly featured transparent dome-like plastic helmets and airtight rubberized fabric garments which markedly restricted mobility and range of motion when fully pressurized. A major breakthrough came in the development of segmented, bellows-like joints at the knees, hips and elbows, which improved use of the limbs. This striking visual aspect of the early 40s suits resulted in their being termed "Tomato worm suits," after the distinctive convolutions of the Tomato Hornworm's body which had inspired the idea.

David Clark Company developed Dr. Henry's original capstan partial pressure suit. The first operational capstan partial pressure suits (PPS) were produced in custom sizes for early rocket powered X-Plane test pilots, by the David Clark Company. They produced the T-1 capstan pressure suit in standardized sizes made of nylon cotton twill. It was chamber tested to 32 km and subsequently flown in a variety of high altitude aircraft. The T-1 Capstan suit (5 to 1 ratio), incorporated an anti-G suit, no chest bladder, and came in 12 standardized sizes for fighter aircraft.

The Model 4 Full Pressure Suit was developed for D-558-2 Douglas Skyrocket test pilots. It was first flown by Navy test pilot Marion Carl for a 26 km altitude record flight. Integrated arm scye bearings (non-sealed) provided improved mobility. Custom sizing was required to tailor the suits to individual test pilots. This was th forerunner of the X-15 full pressure suit and was developed by the David Clark Company and Scott Crossfield at NACA.

The S-2 was a modified capstan partial pressure suit evolved from the T-1 with no anti-G and no chest bladder. It was produced in 12 sizes for bomber aircraft. It used the K-1 helmet, A2 adapter, and C-1 assembly with an F-1 regulator (0.87 l bottle at 120 bar) as an oxygen source. Fired automatically by aneroid at 13 km. Used T block to hook aircraft oxygen system with C-1 assembly backup. Hawks pressure compensated valve in K-1 helmet assembly. David Clark Company.

The USAF Mark I Extravehicular and Lunar Surface Suit, designed and built by Litton Industries, predated both the launch of Sputnik I by the Soviet Union and the creation of the National Aeronautics and Space Administration (NASA) by the United States. Based on a Litton "constant-volume" concept for a so-called "hard suit" in early 1955, the Mark I was tested during 1958-59 for more than 600 hours at simulated altitudes exceeding 100 miles. The unique construction of this suit permitted almost a full range of body motions by the person wearing it. The great success of the Mark I led to the subsequent development of a more refined and satisfactory RX-series "Moon Suits" for NASA. On June 9, 1958 Captain Iven C. Kincheloe Jr., USAF test pilot, tested the Mark I in a simulated flight to 100 miles and found it completely satisfactory.

The RAF Jerkin System conmprised a pressure vest used with a P/Q mask and anti-G suit. Several variations included unsleeved, sleeved and integrated garments proven for short term protection to 18 km. Mk-1 Taylor and M.L. clam shell pressure helmets were used with the sleeved variant for short term protection to 30 km.

Most of the emphasis in the newly formed USAF was directed towards partial pressure suits while the USN placed their emphasis on omni-environmental full pressure suits to combine altitude and immersion protection. The Mark 1 Mod III Suit-Omni-Environmental full pressure Suit was the result of these USN developments. The suit was made in many modifications over a ten year period by B.F. Goodrich. Suits had been developed earlier by Goodrich for the 1942 Doolittle mission against Tokyo.

The Canadian Waistcoat-Mask/Vest/G-Suit was a partial pressure assembly. The Canadians studied variants of this assembly as far back as the early 1940's. Newer variants were studied for short term protection to altitudes of 24 km with the G suit pressurized to 4 times breathing pressure.

MB-1 & 2 were experimental test pilot's partial pressure suits using the K-1 helmet. Chest and abdominal bladders were added to produce the G4A anti-G suit for the Air Defense Command, which provided 5-6 protection to 30 km, used no capstans, and with the MA-1 helmet rather than the K-1.

A capstan partial pressure suit with horizontal shoulder zipper, sewn breaklines, no anti-G, height/weight sizing criteria, used on bomber and reconnaissance aircraft, came in 12 sizes. The MA-2 helmet was by ILC Dover. Many variants of this suit were used for special projects such as the XS-1, X-1A, and X-2 rocket aircraft, the Project Man High balloon flights and Kittinger's Project Excelsior stratosphere parachute jump from 31.3 km in1960.

A partial pressure capstan suit, with vertical shoulder laces, adjustable break lines, anti-G suit, MG-1 Berger Bros. gloves, MA-2 helmet by ILC Dover. Suits by produced by David Clark and Berger Brothers, adapters by Airlock, seat kit and oxygen panel by Firewell. 12 sizes.

By the early 1960s, the US Navy had progressed through a series of developmental models of the full pressure suit that would ultimately take final form in the Mark IV, Model 3, Type 1, a production suit which US Navy aircrew wore on high altitude flights during its cold weather operations.

The XMC-2 full pressure suit developed in the mid-1950s jointly by Wright Field personnel and the David Clark Company for X-15 pilots. It represented a major advance in pressure suit technology, serving as prototype for those used later by Mercury and Gemini astronauts. The suit included an integrated parachute harness. It required custom sizing and was produced in many variants by the David Clark Company as Model S794-5. It allowed the wearer freedom of movement while keeping him comfortable and protected in the event of cabin pressure failure or emergency ejection from the X-15 at extreme altitudes. The suit incorporated a ventilation layer to cool the user and an outer heat resistant layer. The helmet was built by the Bill Jack Company and contained oxygen equipment, microphone and earphones, and an anti-fogging feature.

The David Clark XMC-2-DC prototype, although still in need of substantial development, evolved into the MC-2 suit and then into a standardized Air Force high altitude, full pressure garment known as the A/P 22S-2. This provided greater mobility than the Goodrich A/P22S-3 full pressure suit. 4 layers, 8 sizes, suit controller, oxygen regulator inside helmet, outer layer nylon/polyurethane, dacron link net restraint second layer, third layer silicon impregnated nylon / neoprene pressure bladder, inner fourth diffusion layer was oxford weave. Many variants, used in bombers, the X-15, and other high altitude aircraft.

USAF version of the USN Mark IV suit (B. F. Goodrich and Arrow Rubber Company). Full pressure, two layers, oxygen regulator exterior of helmet, 12 torso sizes, 7 gloves sizes, 2 helmet sizes, pressure relief set in the 0.23 to 0.27 bar range. Helenca coated neoprene material used in mobility areas, nylon impregnated chloroprene in non-mobility areas.

For sustained operation on the lunar surface Project Horizon advocated a 'body conformation suit' having a substantial outer metal surface. This was considered a necessity for several reasons: (1) uncertainty that fabrics and elastomers could sustain sufficient pressure differential without unacceptable leakage; (2) meteoroid protection; (3) provision of a highly reflective surface; (4) durability against the abrasive lunar surface; (5) easy cleansing and sterilisation. It was noted that while movement and dexterity were severe problems in suit design, the earth weight of the suit could be allowed to be relatively substantial. For example, if a man and his lunar suit weigh 120 kg on earth, they would only weigh 20 kg on the moon.

The Mercury spacesuit was a custom-fitted, modified version of the Goodrich U.S. Navy Mark IV high altitude jet aircraft pressure suit. It consisted of an inner layer of Neoprene-coated nylon fabric and a restraint outer layer of aluminized nylon. Joint mobility at the elbow and knees was provided by simple fabric break lines sewn into the suit; but even with these break lines, it was difficult for a pilot to bend his arms or legs against the force of a pressurized suit. As an elbow or knee joint was bent, the suit joints folded in on themselves reducing suit internal volume and increasing pressure.

For the "Vostok" spacecraft, Zvezda developed the KP-V-3A pilot seat, which provided for an emergency escape in the ascent phase and normal ejection of the cosmonaut before landing (there was no soft landing system on Vostok). The SK-1 full-pressure space suit, equipped with an auxiliary life support system and survival features, provided for cosmonaut safety under all expected environmental conditions of flight and after landing.

Hamilton Standard had overall development responsibility for the Apollo suit and associated portable life support system. A subcontract was awarded to International Latex Corporation for development of this suit. After suit development was completed, the production contract was awarded to International Latex, and the initial suit was designated A5L. The A6L design incorporated a thermal/ meteoroid garment. This was never flown. Following the Apollo fire, the suit was redesigned to eliminate flammable materials and was designated A7L (designation A8L was never used). Each Apollo astronaut had three custom fitted A7L suits - one for flight, one for training, and one for flight back-up. The Apollo suit weighed 22 kg and its PLSS Portable Life Support System, 26 kg. The A7LB modification was used for Apollo J series lunar landing missions. The A7LB with an additional thermal garment was used for Skylab. Apollo ASTP, with no EVA requirements, reverted to the original design.

Dave Clark G4C flight suits were designed for wear by Gemini astronauts. Spacesuit designers followed the U.S. Air Force approach toward greater suit mobility when they began to develop the spacesuit for the two-man Gemini spacecraft. The suit was used for the first American spacewalk on Gemini 4, and on all subsequent flights except the Gemini 7 long-duration mission.

A-12, YF-12A and SR-71 full pressure suit with integrated subsystems, parachute harness, automatic flotation system, urine collection device, redundant pressure control and breathing system, thermal protective garment. Custom fitted or in 12 standard sizes and various models.

Between 1964 and 1968 two hard suit assemblies were developed at NASA-ARC, identified as the AX-1 (Ames Experimental) and AX-2. These suits were the first to demonstrate multiple bearing technology. The AX-3 was an 0.5 bar suit, 23 kg, 0.5 to 0.7 bar operational pressure, with improved mobility and was completed in 1977. The program culminated in the development of the prototype AX-5, an all hard suit for high pressure application and zero prebreathe in the 1980's. The AX-5 shared common design goals with the ILC Mark III. For example, they had to be easy to get into and out of, be comfortable to wear, and allow adequate mobility and range of motion for the jobs to be performed. Both were designed to be altered to fit different size astronauts

RX-1 Litton full pressure hardsuit, weighed 40 kg, rolling convolute joint technology, 2-plane enclosure, modular sizing, 1964. Followed by RX-2, 40 kg. in 1964 and RX-2A, 36 kg in 1964. RX-3 and RX-4 versions were down to 27 kg in 1966. The suits were pressurized to 0.34 bar but adaptable to 0.48 bar with an oxygen/nitrogen mixture. The RX-5A was the final configuration of this series.

For the initial Block I Apollo missions a modification of the Gemini G4C suit was to have been flown. After the death of the Apollo 1 crew on the pad, Block I missions were cancelled and the suit never flew. The A1C was a full pressure suit featuring a closed loop system and custom sizing.

Berkut was a modified Vostok Sokol space suit. The needs of the cosmonaut were supplied not through the umbilical cord, but rather through a simple open-cycle environmental control system. Oxygen, used for both breathing and cooling, was contained in a metal backpack. A relief valve vented the suit into space, carrying away heat, moisture, exhaled carbon dioxide, and unconsumed oxygen. There were two relief valve pressure settings - 0.27 atmosphere or 0.40 atmosphere. Sufficient oxygen was carried for 45 minutes of depressurised activity. It was only worn on the Voskhod 2 flight, when Leonov had great difficulties in getting back into the airlock due to the suit's stiffness. It was only after switching to the lower relief valve pressure setting that, bathed in sweat, he was able to get the hatch of the inflatable airlock closed.

A bladder type partial pressure suit, with quick don, 8 sizes, separate garment (CWU-4/P) for immersion protection, inverted neck seal, HGU/8/P helmet, front entry, get-me-down altitude protection, no ventilation initially. Gloves were needed for longer term exposure to high altitude. Used by Kittinger in USAF stratosphere jump, later used by Japanese.

The David Clark G5C lightweight space suit was developed for long duration Project Gemini missions. It was designed to be easily removed during flight and to provide greater comfort than the standard Gemini space suit. Astronauts Frank Borman and James A. Lovell used suits of this type during their 14 day Gemini VII mission in December 1965.

A favourite of Life magazine in the 1960's, this Grumman / Space General design for extended lunar surface operations allowed the astronaut to withdraw his arms from the flexible manipulators and work within the pressurised 'cabin' of the can enclosing his upper torso and head.

Pressure suit which introduced many modifications from the early MC-3A capstan suits. A torso bladder used a redundant full pressure controller and full pressure helmet (1972), 12 sizes, used for high altitude reconnaissance aircraft, exterior cover of various colors worn over pressure suit, This was the last capstan partial pressure suit in operational service - retired with the U-2C aircraft in 1989.

Concept by Otto Schueller, patented by Davis, Moore, Ritzinger and Whitmore at USAFSAM. Passive suit design with pressurization bladders containing closed gas cavities and a breathing bladder connected through the helmet regulator and aneroid-operated visor. Studies to 23 km using the system. Further developed by David Clark Company.

This space suit was designed to provide thermal protection to astronauts using the Astronaut Manoeuvring Unit (AMU). The suit was basically a David Clark Gemini G4C suit with leg covers of aluminised material added to prevent heat damage from the AMU thrusters. Astronaut Eugene Cernan wore the suit during the Gemini IX-A mission in June 1966 in an unsuccessful attempt to test the AMU during extravehicular activity.

The Yastreb suit was the first suit designed in the Soviet Union for extra-vehicular activity. Design began in 1965, and it was initially to be worn on the aborted Soyuz 1/2 1967 crew transfer mission. It was only worn on the Soyuz 4/5 mission, the EVA on Soyuz 7/8 having been cancelled when the spacecraft failed to dock. Yastreb's regenerative life support system was small, designed to be worn on the chest or on the shin, in order to allow the cosmonaut to get through the relatively small Soyuz orbital module hatch. A complex pulley system was used to provide the suit with flexibility.

This suit was one of several concepts leading to the Manned Maneuvering Unit used with the Space Shuttle. The maneuvering apparatus was part of the suit assembly rather than a separate unit as in the MMU. The suit used a cold gas propulsion system which was fed through an umbilical line to the spacecraft.

The NAZ-3 emergency-landing kit was used in cosmonaut training in all seasons and extremes of temperature, and on all manner of terrain: mountains, steppes, tundra, desert, taiga, and in water. The survival kit was designed to gain the attention of rescue crews rather than for long-term use, containing enough supplies for three men over a 72-hour period. The triangular shape of the carrying cases allowed them to be secured snugly in the cramped space between the seats of the cosmonauts onboard the Soyuz craft.

A special variant of the S901, designated the S1010 PPA, was developed specifically for use in the U-2R aircraft in the mid-1960s. This special projects full pressure suit was equipped with integrated subsystems including parachute harness, automatic flotation, redundant pressure control and breathing system, thermal protection. Custom fitted or in 12 standard sizes. Various models used in the U-2R.

Partial coverage garment - two pressure flying suit with diaphragmatic bladder, used with high pressure mask equivalent to A-13 with Hardman kit. Anti-G suit at 3.2 times breathing pressure, get-me-down protection to 20 km. Mask automatically tightened by gas filled expansion pad in back of helmet.

Two hard-shell, constant-volume suits entered development for the Apollo Applications Program. An extravehicular suit was being developed by Litton Industries, and an intravehicular suit was being developed by AiResearch Corporation. Due to budget cutbacks, it was decided to use the A7LB suit instead for Apollo J series lunar landing missions, Skylab and Apollo ASTP.

The Krechet spacesuit was designed by the Zvezda OKB for use on the lunar surface. It consisted of flexible limbs attached to a one-piece rigid body / helmet unit. The suit was entered through a hatch in the rear of the torso. The exterior of the hatch housed the life support equipment. Maximum operation time was ten hours. The Krechet space suit was designed for use on the lunar surface. As in the Orlan suit still used on Mir, the cosmonaut entered the suit by swinging open a hatch in the hard abdomen of the suit at the rear. The backpack containing the life support system was integrated with the hatch. As in Apollo, the gold-coated outer visor of the helment reflected ultra-violet radiation. The integrated Kretchet design meant that no external hoses were required as in the American Apollo suit.

An Air Force orbital space station, the Manned Orbiting Laboratory (MOL), was to place a two-man crew in orbit for extended periods and allow them to work in a shirtsleeve environment. A series of suits were developed specifically for MOL crews. The MD1, MD2, MD3, and MD4 were full pressure suits, closed loop system, in 12 sizes, produced for the MOL definition program by David Clark and Hamilton Standard. The SPD-117, a prototype full pressure suit for the MOL definition phase, included a thermal garment and PLSS by ILC Dover and Firewell. The MOL program was cancelled in 1969. The

In an emergency the 10 kg suit could protect the wearer in open space. The suit included the 2AC-9000-0 pressure suit without the integral helmet, 2AC-9001-00 inner pressurized bladder, and 2AC-9009-00 soft helmet

High Altitude Protective System (HAPS). Hybrid get-me-down system assembled for NASA Dryden Flight Research Center test pilots. Consisted of cut-away anti-G suit with dual bladders (altitude and G), torso counter-pressure garment (Jerkin) and British P/Q type oxygen mask. Breathing pressure to 70 mm Hg at 18 km. Combined effort between DFRC (Barnicki), Edwards AFB (Melvin), RAFIAM (Ernsting), USAFSAM (Morgan), and David Clark Company.

The Orlan spacesuit was used for Russian EVA's on Salyut, Mir, and the International Space Station. It was designed by the Zvezda OKB, and derived from the Kretchet suit intended for use on the lunar surface. It consisted of flexible limbs attached to a one-piece rigid body / helmet unit. The suit was entered through a hatch in the rear of the torso. The exterior of the hatch housed the life support equipment. Maximum operation time was three hours when the Orlan-D version of the suit was first used on Salyut 6. Later Orlan-DM versions of the suit increased this period to nine hours. The integrated design meant that no external hoses were required as in the American space suits. The suit standard pressure was 0.40 atmospheres, so that a prebreathe period of only 30 minutes was required. Electrical power and communications were via an umbilical cord to the station. Control of the suit was via a panel on the chest, with the markings in mirror image. The cosmonaut viewed the panel using a mirror on the wrist of the suit.

The initial series of shuttle flights were equipped with specially adapted SR-71 ejection seats for the two crew. The crew were provided with space suits, derived from the USAF SR-71 suits, which provided them with some protection in the event of ejection or cabin depressurization. The suit was a modified S1030A with an anti-G system. After the initial flights, and until the Challenger disaster, the crew was provided only with oxygen masks.

The S1010 and several S1010 dash variants were later replaced by a further advanced model, the S1031 PPA. The S1031 special projects full pressure suit came in 12 sizes and was used in the TR-1 and U-2R. In the early 1980s efforts to produce a standard single suit capable of being used by both SR-71 and U-2 crews, yielded the S1031C suit, replacing earlier suits on an attrition basis.

The Space Shuttle Extravehicular Mobility Unit (EMU) was a reusable space suit. For a particular crew member and mission it would be tailored from a stock of standard-size parts. Many variants were fabricated over the years. The suit was certified for eight EVA's, and its modular design allowed it to fit 90% of the male/female population. It featured an integrated hard torso with a portable life support system, RF sealed bladder, fabric mobility joint elements, waist bearing, and improved pressure gloves.

Tactical Life Support System. Developed by the USAF and Boeing/Gentex et. al. to provide get-me-down protection from 18 km. Incorporated many new features - including a modular mask, vest, and anti-G suit ensemble integrated to provide PBG for high G maneuvers and PBA for altitude. G trousers provided 4 times the breathing pressure from a molecular sieve oxygen concentration system. There were updated variants of this system in the United Kingdom, Canada, Sweden, and an Advanced Oxygen System for France.

The MMU propellant - non-contaminating gaseous nitrogen stored under high pressure - could be recharged from the orbiter. The reliability of the unit was guaranteed with a dual parallel system rather than a backup redundant system. In the event of a failure in one parallel system, the system would be shut down and the remaining system would be used to return the MMU to the orbiter cargo bay. The MMU, which weighed 140 kg, included a 35-mm still photo camera that was operated by the astronaut while working in space.

NASA Zero Pre-breathe full pressure Suit developed to preclude the need for denitrogenation prior to EVA. The Mk-I ZPS was the precursor to the Mk-3 and was based on shuttle suit geometry with several rigid components for use at a pressure of 0.56 bar. The MK-3 contained both machined/cast aluminum and composite graphite Hard Upper Torso and modular sections for arms and legs to fit 90% of male and female population. Used rolling convolutes at shoulder, and waist; bearings in hips; fabric elbows, knees and ankle joints, ILC Dover, Airlock Corp. and Hamilton Standard.

After the Challenger disaster, it was decided to provide the crew with pressure suits to be worn during launch and re-entry. The Shuttle launch/entry suit (LES) was a partial-pressure suit designed to protect shuttle crew in the event of loss of cabin pressure at altitudes up to 30 km. It also served to insulate the crew from cold air or water temperatures after a bail out from the shuttle. The suit was a modified CSU-4/P with non-conformal full pressure helmet, dual neck dam, integrated exposure suit, parachute harness and flotation equipment. During re-entry, an anti-G protection system consisting of pressure bladders in the legs and lower abdomen fought pooling of blood in the lower body after prolonged exposure to microgravity. The suit also protected the crw from any contamination in the cabin atmosphere. The LES was replaced by the Shuttle ACES suit from 1995 on.

The Soviet Union developed a manned maneuvering unit and flew it from Mir in 1990. The UMK weighed 218 kg. In case of a malfunction, it remained connected by a tether attached to a winch on an EVA mast installed near the Kvant-2 exit hatch of Mir. The UMK was used on only two EVA's, at distances of up to 45 m from the station. Unlike the shuttle MMU, it was only flown tethered to the station. Like the shuttle MMU, it was retired after a few tests.

The Advanced Pressure Suit (APS) was a bladder type partial pressure suit designed and developed by Northrop and ILC Dover for the F-23 Advanced Tactical Fighter. Integrated high altitude, anti-G, Immersion, thermal air cooling and chemical defense protection. Suit bladder had pressure booties and oronasal/full head pressure for PBA and PBG. Breathing bladder/helmet/suit pressurized to 0.24 bar for altitudes above 11 km and 60 mmHg breathing/0.70 bar suit at +9z for anti-G protection. 6 each purchased by USN.

The Strizh full-pressure suit was developed for the Buran programme. It was qualified to protect the cosmonaut in ejections from the spaceplane at altitudes up to 30 km and speeds of up to Mach 3. The suit and the K-36RB (or K-36M-11F35) ejection seat were tested during ascent of a Soyuz booster in a series of five Progress launches (Progress 38 through 42) in 1988-1990.

The David Clark model S1034 PPA was an advanced lightweight full pressure suit which replaced the S1031C (common SR-71/U-2 design) suit and offered significant performance improvements, including enhanced pilot comfort, ease of donning and reduced stress-fatigue. First flown on 20 June 1991, the S1034 PPA was meant to ultimately replace all earlier David Clark S-series suits in use by the US Air Force (which were designed for an approximate 10 year use/life-span). The suit featured integrated life support subsystems to include breathable pressure bladders.

The NASA Mark III was an advanced NASA space suit design of the 1990's. The Mk III hybrid advanced suit assembly consisted of a hard upper torso, brief and hip transition elements, and rolling convolute shoulder, waist and hip abduction/adduction joints. It also offered upper arm, shoulder, hip, waist, and ankle bearings. The Mk III was intended to be pressurized at the relatively high pressurization of 0.56 atmospheres. Although heavier than other suit designs, it offered superior mobility. By combining soft suit joints, hard joints, and bearings, all of the expected lunar or Martian surface mobility tasks could be performed within acceptable levels of effort. The task of kneeling and picking up an object could only be done by the Mk III in comparison with the Apollo A7L or Shuttle EMU suits. Handstands and somersaults could also be performed in the suit. Despite the success of the tests aboard a KC-135 on zero- and reduced-G flights, the NASA EVA Project Office at Johnson Space Center made the decision to pursue a soft suit design (the M-Suit) for future astronauts. The Mark III suit weighed 59 kg and its PLSS Portable Life Support System, 15 kg.

The Shuttle Advanced Crew Escape Suit (ACES) replaced the Launch/Entry Suit (LES) from 1995 on. The ACES fulfilled the same functions as the LES. It was designed to protect shuttle crew in the event of loss of cabin pressure at altitudes up to 30 km, but unlike the LES it was a full-pressure suit. It also served to insulate the crew from cold air or water temperatures after a bail out from the shuttle. During re-entry, the same anti-G protection system used in LES, consisting of pressure bladders in the legs and lower abdomen, fought pooling of blood in the lower body after prolonged exposure to microgravity. The suit also protected the crew from any contamination in the cabin atmosphere. ACES also provided a liquid cooling undergarment.

The D-1 (S1035X) space suit assembly was developed to provide a functional all-soft suit technology demonstrator prototype model to be used for mobility system testing and evaluation. The design of the suit was based on the S1035 Advanced Crew Escape Suit (ACES) worn by Shuttle crew-members during launch and re-entry phases of flight, but was upgraded with specific mobility enhancements. The design objective for the D-1 suit was for a predominantly "all-soft" (i.e., fabric) suit system which incorporated minimal bearings and could operate at 3.75 psi pressure. The shoulder joint incorporated a cable-assisted, flat-patterned fabric joint system with an upper arm bearing. The upper arm bearings were the only bearings used in the D-1 suit. The waist/hip joint arrangement was similar in nature to the shoulder joint in the use of a flat-patterned fabric element coupled with a cable-assisted system. The elbow, knee, and ankle joints all utilized fabric, flat-patterned joint elements. The suit incorporated a horizontal, mid-body closure ring for donning and doffing. Additional ancillary items that were representative of an extra- vehicular suit configuration would be integrated into the D-1 configuration. The prototype D-1 suit assembly weighed 12 kg., exclusive of the ancillary extravehicular items.

In the fall of 1998, two soft suit prototypes were delivered to NASA by two companies, ILC Dover and David Clark. ILC Dover's M-Suit operated at a pressure of 0.26 atmospheres and weighed 30 kg. In comparison to the Apollo and Shuttle suits, the M-suit had a greatest range of motion and the smallest joint torque. It utilized as government furnished equipment the shuttle helmet, neck ring, and wrist disconnects and was designed to interface with the shuttle liquid cooling and ventilation garment, communications carrier assembly, and gloves.