The New Apollo And Skylab Space Suits

ILC Industries, Inc., through its Dover/Frederica Division in Delaware, Is the prime NASA contractor for design, development, and manufacture of space suits for the Apollo and Skylab Programs. These suits afford the necessary safety, comfort and mobility to the astronauts during Apollo and Skylab missions.

Space suit development is a tribute to American Industry. For Instance, Du Pont, the world's largest chemical corporation, developed materials used in 20 of the 21 layers In the ILC Industries space suit. None of these materials were developed with the moon in mind. Some were new materials, like "Kapton" film. Others, such as nylon, were discovered more than thirty years ago by scientists who had no Idea of the distance the results of their research would travel some day. Achievements In science are often put to use in unexpected places. In the case of the space suit, materials which were developed for use on earth ultimately found a place on the moon.

The space suit is an air-tight anthropomorphic structure called the Pressure Garment Assembly or PGA. In the space suit, the astronaut is protected from the extreme range of temperatures, the near vacuum of space and the micrometeoroid flux density that might be encountered in space or on the moon's surface. Without this protection, a man could not live, and would die within seconds after being exposed to such hostile environments.

There are two basic configurations of the suit used to support Apollo Missions: an In-travehicular (IV) configuration designated as the CMP A7LB PGA, and an Extravehicular (EV) configuration identified as the EV A7LB PGA. The CMP A7LB pressure garment configuration is worn by the Command Module

Pilot. The EV A&B configuration is worn by the Crew Commander and the Lunar Module Pilot. A slightly modified version of the EV A7LB PGA is planned for use during Skylab missions.

The complete Extravehicular Mobility Units used for Apollo and Skylab missions are shown on the front cover. The Extravehicular Mobility Unit or EMU configured for Skylab missions, shown in the foreground, is the most current space suit configuration for use in space programs.

The pressure garment assembly interfaces with the spacecraft environmental control system, or the Apollo Portable Life Support System (PLSS) or the Skylab Astronaut Life Support Assembly (ALSA). The pressure garment is operational at differential pressures of 3.70 to 3.90 pounds per square Inch; In temperatures of -290 to +310 degrees Fahrenheit for Apollo missions or -180 to +277 degrees Fahrenheit for Skylab missions; and In micrometeoroid flux densities normally expected within the lunar orbit perimeter about the earth or a 300,000 mile orbit. The pressure garment permits low torque body movements for operating spacecraft controls and specially designed devices required for space exploration or traversing the lunar surface.

When pressurized, the differential pressures Impose stress or tension on the suit wall. The "soft" suit becomes very rigid or stiff, and almost impossible to bend except in those areas where specially designed joints are provided to accommodate normal body flexure. An example of this stiffness: inflate a large cylindrical balloon or the inner tube of a tire, the balloon or tube will become very stilt and almost Impossible to twist or bend. Without these specially developed joints for the space suit, It would be virtually impossible for the astronaut to do useful work on the moon's surface. These special joints are installed Into the CMP A7LB suit at the knees, wrist, shoulders, elbows, ankles, and thighs. The EV

A7LB suit was further modified to include special joints at the neck and waist to allow bending movements in those areas. This added suit flexibility permits the astronaut to conserve his energy, reduce fatigue and to work for longer periods on the lunar surface. Normal body movements in the suit cause the suit joints to bend. The force required to flex these joints is applied against the inner suit wall or gas retaining layer. To preclude direct wear on the gas-retaining layer, the suit is fitted with an inner scuff layer of nylon fabric.

Astronaut Lcvg

Entrance Into the suit is made through restraint and pressure- sealing zippers. The entrance opening used In the CMP A7LB assembly extends down the center of the back, from the neck area to the front crotch area. The EV AMB suit employs entrance zippers that extend from the let t side of the waist, around the back to the right side of the waist, and diagonally up to the right chest area of the suit. Routing of the zippers in the EV A7LB suit was changed from that employed in the CMP model to accommodate the new neck and waist joints. The entrance zippers can be operated by the crewman if required, but zipper actuation is normally done with the assistance of a fellow crewmember.

Skylab Space Suit Photo

There are two protective envelopes employed in the space suit: an Inner pressurizable envelope, and an outer thermal and micrometeoroid protective envelope. The inner pressurizable envelope Is called the Torso and Limb Suit Assembly (TLSA); this assembly Interfaces with a detachable helmet, and a pair of removable gloves. The outer envelope used for thermal and micrometeoroid protection Includes an Integrated Thermal Micrometeoroid Garment (ITMG), a Lunar Extravehicular Visor Assembly (LEVA) or Skylab Extravehicular Visor Assembly (SEVA), and a pair of lunar boots that are used for Apollo Lunar missions only.

The torso and limb suit consists of an inner comfort liner, a rubber-coated nylon bladder, and an outer nylon restraint structure with the exception of the shoulder, elbow, wrist, thigh and knee joints. These joints are single wall, integrated restraint and bladder, bellows-like structures.

The Thermal Micrometeoroid Garment (ITMG) Is composed of an inner layer of rubber-coated nylon, alternate layers of aluminized material separated by a low-heat-conducting spacer fabric, and an outer layer of fire and abrasion resistant material. This thermal cross section employs the same Insulation principle as the "Thermos" bottle when the suit is exposed to the near vacuum of space.

The Lunar Extravehicular Visor Assembly (LEVA) or Skylab Extravehicular Visor Assembly (SEVA) includes a shell assembly that fits over the helmet, and that clamps around its base. Two visors, two side-eyeshades, and a center eyeshade are supported by the shell. The outer sun visor employs a gold coating that reflects solar heat and light from its surface. The inner protective visor is transparent, although it includes an Inner coating that retains heat being emitted from the face. The protective visor is used without the sun visor during operations in shadow areas where visibility through the dark sun visor would not be adequate. The visors and eyeshades are adjustable and can be moved to positions selected by the crewman for his comfort and safety.

The Lunar Boots are slip-on assemblies that include a cross section of materials similar to those In the ITMG. There are additional layers of materials used in the boot sole as necessary to reduce the transfer of heat from the lunar surface to the foot. Metal-woven fabric or "Chromel-R" forms the outer shell of the boots to resist high lunar surface temperatures and surface abrasion. The outer structure of the boots in the sole consists of silicone rubber that is sewn to the outer metal fabric shell and affords Improved wear and thermal protection to the boots.

For each PGA, there are two pairs of gloves used to support Apollo and Skylab missions: Intravehicular (IV) Gloves and Extravehicular (EV) Gloves. The IV Glove is a single-wall restraint and bladder structure formed to fit the crewman's hand. For scuff protection and added structural support, an outer gauntlet and palm restraint system is fitted over the glove. The palm restraint affords Improved hand dexterity for operating spacecraft controls and special devices. The EV Glove Includes an IV Glove that Is fitted with an outer thermal glove that employs a similar cross section to that of the ITMG. For abrasion and thermal protection, the outer shell is constructed of metal-woven fabric, and the fingertips are fitted with silicone rubber caps. The outer thermal glove extends well back over the IV glove-TLSA juncture.

Gaseous oxygen is circulated through the suit by the PLSS (backpack) or ALSA, or the spacecraft environmental control system for respiration, pressurization, and ventilation purposes. The oxygen is directed to the helmet from Inlet gas connectors on the suit, down over the body, to the arm and leg extremities, and then is directed through ducts to the exhaust gas connectors. The Impurities are removed from the gas stream as it passes through the spacecraft environmental control system or portable life support system, and then is recirculated through the suit.

The ventilation system removes body heat from within the suit during lV operations, or when free space EV activities are performed remote from the spacecraft. During lunar surface excursions the metabolic heat generated by the body exceeds the capability of the ventilation system, so a liquid cooling system Is employed which removes the major portion of body heat from within the PGA;

thereby reducing fatigue as a result of body dehydration through perspiration. The Liquid Cooling Garment (LCG) consists of a network of polyvinyl tubing that is supported by spandex fabric. The garment is worn next to the skin and covers the entire body exclusive of the head and hands. A liquid coolant or water is circulated through the tubing from the portable life support system. In the suit, heat is transferred from the body to the liquid through the tubing wall, and in the portable life support system, the heat is removed from the liquid before it is re-circulated back to the LCG.

Providing the spacesuit for the Apollo & Skylab Programs is just one part that ILC plays in the role of protecting man from hazardous environments. ILC Industries, Inc. is proud of its role in the space program and vigorously supports the ever-expanding field of aerospace technology. We have over twenty years of experience in research, development, and manufacture of air-inflated assemblies, pressure vessels and life support systems. This experience has provided a sound base for our continuing research, development and design of aerospace life support equipment, and has given ILC its place as the leader in this field.

Although the Apollo and Skylab programs represent a tremendous challenge and a great step forward in aerospace technology, we at ILC Industries see them as the beginning rather than the end of a long line of successful efforts. We plan to utilize our experience and knowledge gained on these programs to advance the state-of-the-art in other products for both government and Industry. The company has already utilized materials applications developed for Apollo and Skylab equipment in other products, which are being manufactured. In this manner, the results of technology gained on space programs are passed along to the consumer and the public. The walk on the moon is truly a step into the future.

0n July 20, 1969, as the world watched in awe when Neil Armstrong made his "One Small Step For A Man" onto the lunar surface, a small engineering company located in Dover, Delaware was beaming with pride. That company was ILC Dover, and the pride felt at ILC was surely justified; they designed and manufactured the space suit astronaut Armstrong wore while making American history on the moon. That same pride was sustained throughout all fifteen Skylab and Apollo/Soyuz Test Project (ASTP) mission, during which ILC produced space suits performed flawlessly. It is of little wonder then, that in 1977 ILC Dover, as part of the Hamilton Standard team, was selected by NASA as Space Suit Assembly (SSA) contractor for the Space Shuttle program.

The MC Shuttle space suit is a pressure retention structure that, together with a life support system provides a life-sustaining environment, which protects the astronaut against the hazards of space. Such hazards include a vacuum environment, temperature extremes of -180 to +277 degrees Fahrenheit, and the impact of micrometeoroids and orbital debris.

Unlike the space suits used in the Apollo or Skylab Programs, where the entire suit was custom manufactured for a specific astronaut, the Shuttle suit is comprised of separate components which can be assembled to make space suits to fit almost anyone (male & female). Several sizes of each component are manufactured and placed on the shelf for future use. When needed, the components are selected from the shelf (depending on the astronaut's size) and assembled into a complete space suit. The SSA and the Life Support System (LSS), when combined, become the Extravehicular Mobility Unit, or EMU. The EMU is used for all Shuttle program extravehicular space activities.

The SSA is designed and has been tested for an eight-year operational life. The design permits low torque body movements required for performance of tasks in space.

When pressurized, the "soft" material portion of the suit becomes very rigid and nearly impossible to bend except where specially designed joints are provided. Such is the case when you inflate the inner tube of an automobile fire.

The tube becomes very stiff and is difficult to twist or bend. Without these joints it would be virtually impossible for the astronaut to do useful work. These special joints are located at the knees, wrists, shoulders, elbows, ankles, thighs and waist of the SSA. Normal body movements by the astronaut cause the suit joints to bend. This flexibility permits the astronaut to conserve energy, reduce fatigue and to work for long periods of time.

A typical cross-section of the SSA is 11 layers deep, consisting of the liquid Cooling & Ventilation Garment (LCVG) (2 layers); pressure garment (2 layers); and the Thermal Micrometeoroid Garment (TMG) (7 layers). Simply stated, the LCVG maintains astronaut comfort, the pressure garment provides containment of the breathing air, and the TMG protects against the micrometeoroids which hit the suit, and insulates the astronaut from the extreme temperatures of space.

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Responses

  • donald
    Where is the pressure control garment on space suit?
    7 years ago
  • AHMED
    Where are space suit made?
    7 years ago
  • maija
    What is an astronaut suit made of?
    6 years ago

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