Extravehicular Mobility Unit (EMU)

8/7/2019 Extravehicular Mobility Unit (EMU)

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EXTRAVEHICULAR MOBILITY UNIT

(EMU)

Crew and Thermal Systems Division, NASA

Johnson Space Center

2101 NASA Road 1

Houston, Texas 77058

281-483-9230


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INTRODUCTION

The Extravehicular Mobility Unit (EMU) provides a crewmember with the life support

equipment and mobile pressure enclosure necessary to perform Extravehicular Activity

(EVA) while in an earth orbit. The EMU consists of two major subsystems; the Life

Support Subsystem (LSS) and the Space Suit Assembly (SSA).

SPACE SUIT ASSEMBLY (SSA) provides:

Atmosphere containment

High mobility body joints

Thermal insulation

Cooling distribution Drinking water

Waste collection

Sunlight and solar radiation protection

Micrometeoroid/Orbital Debris (MMOD) protection

Interfaces for attachment of other EVA-related equipment

LIFE SUPPORT SUBSYSTEM (LSS) provides:

Primary oxygen supply

Suit pressurization and ventilation

Communications

Breathing gas purification

Temperature control

Power

An interface for servicing

Interfaces for attachment of other EVA-related equipment

Suit health display feedback

Independent emergency oxygen supply

Suit health check instrumentation and telemetry data

The Shuttle Extravehicular Mobility Unit (EMU) has dramatically demonstrated theability of humans to work effectively in space. EVA highlights include the refueling and

repair of satellites on orbit, retrieval of satellites for refurbishment on earth, and the

assembly of Space Station structures. The EMU has and will continue to play a vital role

in allowing Americas Space Shuttle to fulfill a wide spectrum of space tasks such as

inspection, maintenance, repair, construction and if necessary, rescue operations. In

addition, the present Shuttle EMU is used for International Space Station (ISS) EVA

activities assembly and operations.


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The EMU is designed to fit both men and women. The space suit/life support system,

which serves as a one-person spacecraft, provides protection and earth-like mobility for

astronauts working in space.

The EMU is designed to accommodate an EVA mission consisting of the followingcharacteristics:

a) Total duration of 7 hours maximum or 6 hours maximum under the worst-casesolar exposure.

b) An average metabolic rate of 1000 Btu/Hr for 7 hours.

c) Peak metabolic rates of 2000 Btu/Hr for 15 minutes and 1600 Btu/Hr for 1 hour atanytime within the EVA.

d) Minimum rate of 400 Btu/Hr for 30 minutes after an average work rate of 1000Btu/Hr and followed by a rate of 700 Btu/Hr for up to 30 minutes.

e) Prebreathe (a process which flushes Nitrogen from the blood, thereby reducing therisk of experiencing Decompression Sickness (DCS)) can be as short as 40 minutes

with a 10.2 psia cabin pressure or as long as 4 hours with a 14.7 psia cabin

pressure.

f) System will provide 2 hours DCS Treatment with a cabin pressure of 14.7 psia.

LIFE SUPPORT SUBSYSTEM (LSS)

The Life Support Subsystem (LSS) consists of subsystems, which are briefly described in

the following paragraphs:

1) Primary Life Support Subsystem (PLSS)

2) Secondary Oxygen Pack (SOP)

3) Display and Control Module (DCM)

4) Service and Cooling Umbilical (SCU)

5) EMU Electrical Harness (EEH)

6) Airlock Adapter Plate (AAP)

7) Contaminant Control Cartridge (CCC)


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8) Battery

9) Bends Treatment Adapter (BTA)

10)Secondary Oxygen Pack Checkout Fixture (SCOF)

11)Helmet Holding Fixture (HHF)

12) Power Harness

PRIMARY LIFE SUPPORT SUBSYSTEM (PLSS)

The PLSS is made up of four distinct circuits:

1) Oxygen Ventilation Circuit

2) Primary Oxygen Circuit3) Feedwater Circuit4) Liquid Transport Circuit

These circuits provide suitable breathing environment and

thermal control for the crewmember inside the Space Suit

enclosure. The Primary Oxygen Circuit supplies oxygen at

regulated pressure to the Oxygen Ventilation Circuit for

crewmember breathing, SSA pressurization, and Water

Tank water expulsion. The fan portion of the

Fan/Pump/Separator, located in the Oxygen Ventilation

Circuit, circulates the oxygen and gas exhaled by thecrewmember through connecting ducts and items. The

exhaled CO2 is removed from the breathing environment by

a CCC or a METOX cartridge. Cooling and humidity

removal occurs as the oxygen circulates through the

sublimator. Additionally, primary oxygen is also directed

through ducting to pressurize the water storage tanks

located in the Feedwater Circuit. The water storage tanks

supply expendable water at regulated pressure to the

sublimator. The feedwater circuit in the sublimator is open

to atmosphere (vacuum), and, as the expandable water is

fed into the sublimator, it freezes and then sublimates to

space. This sublimation removes heat from the Liquid

Transport Circuit. The pump circulates cooling water

through the Liquid Transport Circuit, which includes the

Liquid Cooling and Ventilation Garment of the SSA, worn

by the crewmember. The water removes heat from the

crewmember and is cooled by the sublimator.


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SECONDARY OXYGEN PACK (SOP)

The SOP attaches to the bottom of the PLSS and

provides 30 minutes of back-up pressure regulated

oxygen in the event that:

1) The primary oxygen supply is exhausted

2) Primary pressure regulation is lost, via a regulator failure of excessive oxygendemand

3) One of the Purge Valves are opened due to: a) The PLSS fails to removecontaminates in the ventilation circuit, heat, or humidity; b) Ventilation flow

drops below acceptable levels.

DISPLAY AND CONTROL MODULE (DCM)

The DCM provides EVA crewmembers electrical and

mechanical controls required for one person operation

of the EMU, and contains a Liquid Crystal Display

(LCD). The LCD, in conjunction with the Cautions

and Warning System (CWS) displays EMU operational

information in alphanumeric format to the EVA

crewmember.

SERVICE AND COOLING UMBILICAL (SCU)

The SCU connects the EMU to the orbiter service panel

and is used to 1) replenish PLSS consumables, 2) supply

cooling and expendables during umbilical operations,

and 3) allow wastewater drainage. The CCC is the only

consumable not recharged by the SCU.

EMU ELECTRICAL HARNESS (EEH)

The EMU Electrical Harness is located within the Hard Upper

Torso (HUT) and connects the Communication Carrier

Assembly (CCA) and the biomedical sensors to the EMU

Electrical System.


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AIRLOCK ADAPTER PLATE (AAP)

The AAP is a mounting structure used to attach the EMU to the

orbiter airlock wall. The EMU is secured to the AAP by four

mounting pins and the AAP is retained to the orbiter airlock wall

by three supports.

CONTAMINATION CONTROL CARTRIDGE (CCC)

The CCC is a crewmember replaceable module used in the

PLSS to remove CO2, odors, particulate and other

contaminants from the Oxygen Ventilation Circuit.

BATTERY

The battery supplies all power to the EMU excluding EMU

lights when it is not operating on vehicle power via the SCU.

BENDS TREATMENT ADAPTER (BTA)

The BTA is an emergency device, which is used on orbit in the

event of an EVA crewmember contracting decompression sickness.

It permits EMU usage as a hyperbaric (8 psi above airlock

pressure) bends treatment chamber.

SECONDARY CHECKOUT FIXTURE (SCOF)

The SCOF is a device used in place of the Helmet to seal

off the Oxygen Ventilation Circuit and provide over

pressurization protection during pre-EVA activity (SOP

checkout, fan checkout and water discharge/recharge).


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HELMET HOLDING FIXTURE (HHF)

The HHF provides for the storage of a Helmet/EVVA. The HHF

mounts to the airlock floor during launch and landing.

POWER HARNESS

The Power Harness is designed to reduce the profile of

the glove by moving the power source for the heating

elements from its original location on the back of the

EMU glove to the PLSS. Each glove contains one heater

element per fingertip powered by the Rechargeable EMU

battery Assembly (REBA) located on the right side of

the PLSS. The battery, which will provide up to eighthours of operation, is connected to the heater elements

via 8 to 10 feet of copper cabling that runs under the

TMG from the battery, down through the arms of the

EMU. The Power Harness provides an electrical

connection between the Electronic Cuff Checklist, TV

Camera, and the REBA.

SPACE SUIT ASSEMBLY (SSA)

The Space Suit Assembly (SSA), consists of nine subassemblies which are describedbelow:

1) Communications Carrier Assembly (CCA)

2) Hard Upper Torso (HUT)

3) Arm Assembly

4) Lower Torso Assembly (LTA)

5) Helmet

6) Gloves

7) Liquid Cooling and Ventilation Garment (LCVG)

8) Extravehicular Visor Assembly (EVVA)


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9) Disposable In-Suit Drink Bag (DIDB)

The SSA interfaces with the Primary Life Support Subsystem (PLSS) and the Display and

Controls Module (DCM) at the HUT. The PLSS provides mechanical, electrical, and

fluid interfaces where it joins the HUT.

The SSA components are designed to closely approximate the natural anthropometric

joint movements. This is accomplished with low-torque mobility joints at the hip, knee,

ankle, and hand and with low-torque mobility bearings at the shoulder, waist, elbow and

wrist.

COMMUNICATIONS CARRIER ASSEMBLY (CCA)

The CCA is a cloth aviator-type cap worn under the pressure suit

helmet. It fits over the crewmembers head and snaps into place

with a chin or neck strap. It contains microphones and

headphones for communicating with crewmembers and receivingcaution and warning tones.

HARD UPPER TORSO (HUT)

The HUT is the portion of the pressure suit that

encloses the upper torso of the body. It provides

the structural mounting interface for most of the

EMU; Helmet, Arms, Lower Torso Assembly,

Primary Life Support Subsystem, Display and

Control Module, Power Harness, and the Electrical

Harness. It is made of a fiberglass shell. Integral

to the HUT are passageways for fill and drain

water, vent air, and cooling water. Tubing for vent

air and cooling water is attached to these

passageways, leading to the Multiple Water

Connector. The Multiple Water Connector

interfaces to the Liquid Cooling Vent Garment

(LCVG) with its cooling water and vent systems.

The Thermal Micrometeoroid Garment (TMG)

provides protection for the HUT.


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ARM ASSEMBLY

The left and right Arm Assemblies are

flexible, anthropomorphic pressure

vessels made of heat sealed, urethane-

coated, nylon bladder fabric enclosed inpolyester restraint fabric. The assembly

contains the shoulder joints, upper arm

bearings, elbow joints, and wrist bearings

that permit joint mobility. Thermal

protection for the arm assemblies is

provided by TMG.

The lower arm assembly uses adjustable

arm brackets as well as a metal Arm

Sizing Ring for sizing. These items were

designed to allow crewmembers toperform sizing tasks on-orbit. There are

four adjustable arm brackets (cams), two

at each end of the arm segment. Each

cam can adjust .025 for a total of .5.

The Arm Sizing Ring adds an additional

0.5 of length to the lower arm.


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LOWER TORSO ASSEMBLY (LTA)

The LTA encompasses the lower torso, legs, and feet of the

crewmember. It is composed of an Adjustable Waist

Assembly, Trouser Assembly, Leg Assembly and BootAssembly. The adjustable waist allows the crewmember to

make two, one-inch adjustments to the length of the waist on

orbit, when other crewmembers need to wear the same suit.

These fabric elements are joined through attachment to

hardware, and in all cases the attachment is by flange

mounting. Boots are joined to the Trousers by the Boot

Disconnects; Trousers are joined to the Waist Assembly

through the Waist Bearing, and the Waist Assembly is

attached to the Body Seal Closure (BSC). Interface of the

LTA to the HUT is accomplished via the BSC. Thermal

protection for the LTA is provided by TMGs. The TMGelements for the LTA are the Boot, Leg, Brief, and Waist

TMG Assemblies. The TMG components are sized to fit the

corresponding Restraint Assemblies.

The LTA can be sized with adjustable le brackets and sizing rings. The leg assemblies

contain brackets that can be adjusted in .5 increments for a total of 1.0. Crewmembers

with long legs can be accommodated by adding a 0.5 Thigh Sizing Ring. The distance

between the knee and the foot can also be adjusted with Leg Sizing Rings in 0.5

increments from 0.5 to 1.5 rings.

HELMET

The Helmet is the portion of the pressure suit providing a

pressure vessel for the head. It is made of clear

polycarbonate bubble with a neck disconnect and

ventilation pad. The Helmet contains the following

subassemblies: Bubble, Neck Ring, Combination Purge

Valve (CPV), and Vent Pad. The Bubble, Neck Ring and

Vent Pad are permanently secured while the CPV, attached

to the left side of the Bubble with three screws, is

removable. The Neck Ring provides for quick disconnect

of the Helmet from the HUT. The Vent Pad, mounted inthe back of the helmet, directs vent flow oxygen from the

HUT to the front areas of the Helmet Bubble. The CPV

provides redundancy for O2 circulation in the event that

your O2 vent flow fan fails. The Helmet provides for semi-

permanent attachment of a supplemental Extravehicular

Visor Assembly (EVVA) for all extravehicular operations.


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GLOVES

The Gloves are the active interface between the

crewmember and the work being performed. As

such, they must perform a variety of functionswhile preserving an effective degree of tactility.

The glove must also provide a protective barrier

against the natural environment, as well as work

place hazards. The gloves have electrical heaters

in the tips of the fingers that can be turned on by

the crewmember, when desired. The EV glove is

comprised of the following basic components:

Restraint, Bladder, and TMG.

LIQUID COOLING AND VENTILATION GARMENT (LCVG)

The LCVG is a conformal garment worn under the pressure suit to

maintain body temperature. It has ethylene vinyl acetate tubing woven

through the spandex restraint cloth. Cooling water LCVG also

contains the ducts for returning vent air to the HUT for transfer to the

PLSS, and retains the dosimeter, signal conditioner, biomedical leads,

and an electrical grounding lead for the crewmember. The multiple

water connector interfaces to the HUT with its cooling water and vent

systems.

EXTRAVEHICULAR VISOR ASSEMBLY (EVVA)

The EVVA fits over and attaches to the Helmet to

provide the crewmember with visual, thermal,

impact, and micrometeoroid protection in space. It

has a polycarbonate shell, stationary polycarbonate

Protective Visor, movable polysulfone Sun Visor,

and movable fiberglass/epoxy Center and Side

Eyeshades. The Sun Visor and the Center Eyeshade

are manually adjustable by rotating the supporting

hubs. Grasping a tab with the hand moves each Side

Eyeshade. A Thermal Micrometeoroid Garment

covering is attached to the outside of the shell.


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IN-SUIT DRINK BAG (DIDB)

The IDB is a re-useable heat-sealed, flexible

container made of polyester based polyurethane film

and comes in two sizes. It can hold up to either 21

oz. Or 32 oz. of drinking water for use during EVA.It is mounted to the inner front wall of the HUT with

Velcro and has a tube extending to the neck area.

There is a Drink Valve, which can be adjusted to a

position within reach of the lower right corner of the

mouth. Sucking on the mouthpiece opens the valve

and permits the crewmember to drink water from the

IDB.

DISPOSABLE IN-SUIT DRINK BAG (DIDB)

The DIDB is an expendable heat-sealed flexible

container made of polyethylene film. It holds 32 oz. of

drinking water for use during EVA and is mounted to the

inner front wall of the HUT with Velcro. There is a tube

extending from the drink valve to the neck area that can

be placed in either the lower right or lower left corner of

the mouth. Netting in the bag creates a wicking action in

0-G so water propagates to the drink valve. Sucking on

the mouthpiece opens the diaphragm valve and permits

the crewmember to drink water from the DIDB.


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SUPPORT AND ANCILLARY EQUIPMENT

EMU Support and ancillary equipment includes:

-EMU light An incandescent lamp and batteryassembly that mounts on the EVVA to provide

the EVA crewmember with light as needed.

- EMU TV A small EVVA mounted

modularized television transmission assembly,

including camera that provides the EVA

crewmember with mobile camera capability.

- Electronic Cuff Checklist a computer-based device attached to the glove garmentthat provides menu driven instructions and information to the crewmember.

- Tethers Strap like devices used to tether tools and other items to the EMU and theEMU to anchor points on the Orbiter and the International Space Station (ISS).

35 Foot Tether Waist Tether Wrist Tether

- Airlock stowage bag A bag used to store items during suit donning or doffing.

- EMU prep kit A kit containing items used in preparing the EMU for EVA or for

storage after an EVA.

- Antifog wipes

- Package of tissue-type wipes

- Scissors with a lanyard


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- EMU maintenance kit A kit containing items used in normal and contingency

maintenance of the EMU as well as spares for some items in the prep kit.

- Valsalva devices

- Stericide wipes

- Lubricant wipes- Antifog wipes

- SOP removal tool

- Thermal cover lacing cord and needle

- LTA Donning handles Devices used during suitdonning to aid the crewmember in mating the lower torso

to the upper torso.

- Wrist mirror A mirror attached to the wrist of the EMUfor viewing EMU controls out of crewmembers normal

field of view.

- Cuff checklist A short form checklist of EVAprocedures and EMU malfunction procedures attached

to the wrist of the EMU for use during EVA.

- EMU scissors A pair of scissors located in an EMUpocket. They are tethered to the EMU for use as

needed to cut tethers, thermal blankets and other

items.

- Adjustable Thermal mittens Mittens

that fit over the gloves of the EMU to

provide additional thermal protection.


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- Mini-work station (MWS) A device

that attached to the HUT and is used in

the transport and management of tools.

- Maximum Absorbency Garment (MAG)

- A disposable device used for collecting

crewmember urine.

- Thermal Comfort Undergarment (TCU) -A crewmember garment worn under the LCVG

used to enhance physical comfort and to allow

LCVG to remain clean for a longer period of

time.


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NASA EVA PATCH

The theme of the patch is Extending the Dimensions of Man. It is derived from the

Leonardo da Vinci sketch entitled The Dimensions of Man and is meant to be an

expansion of the dimensional, medical, and scientific aspects of the original work. It is

fitting that the theme of the patch is associated with the original da Vinci work since the

evolution of the Space Shuttle EMU from its Gemini, Apollo, and Skylab originsrepresents the closest achievement of the ultimate EMU design goal. That of providing

EVA mobility limited not by hardware but by mans natural range.

The three stars represent the three historic milestones in U.S. extravehicular activity

Americas first EVA by Ed White during Gemini IV, mans first steps on the lunar

surface by Neil Armstrong and the EVAs performed by Pete Conrad and Joe Kerwin to

repair and eventually save the Skylab Space Station. The NASA EVA patch is located on

the right shoulder of the space suit and represents the EVA community.


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EMU CONTRACTORS

The EMU design, development and manufacturing program is being accomplished by

many companies located across the United States with all of them working closely with

the NASA. Four of the major contractors are:

Prime contractor for the EMU:

Hamilton Sundstrand

One Hamilton Road

Windsor Locks, Connecticut 06096

Phone: (860) 654-2854

Contact: Bob Poisson

Subcontractor for the Space Suit:

ILC Dover, Inc.

One Moonwalker RoadFrederica, Delaware

Phone: 302-335-3911

Contact: Phil Spampinato

Subcontractor for the Space Suit Hardware:

Air-Lock Inc.

Wampus Lane

Milford, Connecticut 06460

Phone: (203) 878-4691

Contact: Jim Edwards

Subcontractor for the Space Suit Visor Coatings:

Deposition Research Laboratory, Inc.

530 Little Hills Blvd.

St. Charles, Missouri 63301

Phone: (314) 940-0768

Contact: Steve Chelli

The following four pages contain additional information on these companies.


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SPECIFICATIONS

Mission Duration: 7 hours EVA

Operating Environment: 0 psia (pounds per square iabsolute) to 14.7 psia

Suit OperatingPressure: 4.3 psid (pounds per squareinch differential)

Emergency Life Support: 30 minutes

Useful Life: Up to 30 years with appropriate

maintenance

Modular Components: 18 different items -7 Life Support System 11 Space SuitAssembly

Sizing: Modular assembly fits5th to 95th percentile maleand female astronauts

Construction: Space Suit Assembly Urethane-coated, nylon pressurebladder Orthofabric and aluminized mylarthermal/meteoroid garment Fiberglass hard upper torso Ball-bearing joints

Polycarbonate helmet and visors On-orbit resizingLife Support System Interchangeable subsystem modulefor ease of maintenance and servicin Expendables replaceable orrechargeable on orbit

Weight: Approximately 275 pounds

Donning: 15 minutes

Workaids: Compatible with

- Work stations- Manual and power tools- Helmet-mounted videocamera and lights- Tethers- Foot restraints- Simplified Aid for EVARescue (SAFER)- Electronic Cuff Checklist(ECC)

Hamilton Sundstrand provides theExtravehicular Mobility Unit for NASA. Thisintegrated space suit/ life support systempermits astronauts to work comfortably andsafely in space.

The EMU is modularized to fit both men andwomen. The space suit/life support system,which serves as a one-person spacecraft,provides protection and earth-like mobility forastronauts working in space.

Space Suit Assembly (SSA) provides: Atmosphere containment High-mobility and Iow-torque body joints Thermal insulation Cooling distribution Drinking water Waste collection Sunlight and solar radiation protection Micrometeoroid and debris protection

Life Support System (LSS) provides:

Oxygen supply Suit pressurization and ventilation Communications Breathing gas purification Temperature control Independent emergency life support

For safety, the EMU is constantly monitored bya Caution and Warning System, which

monitors 17 sensors, contaminant levels andremaining expendables such as oxygen, waterand power.



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Apollo Used for IVA During Trans Lunar Flight Used for All Lunar EVA & Transfer Vehicles Custom Fit, Pure O2, Water Cooled, 3.8 psi 160 hrs on Lunar Surface Operational Environment: -250F to +250F,

Dust

Shuttle Designed for Standard Sizing, 4.3 psi Continuing Glove Improvements Operational Environment: Payload Bay - Deep

Space

Cross Section of Ex erience

NASA Space Suit Design Highlights

Space Station Redesigned for Higher Mobility, On Orbit

Changeout

Heated Glove with Better Tactile Capabilities Greatly Increased Cycle Life

Mark III TechnologyDemonstrator

Benchmark Suit for Mobility High Pressure 8.3 psi Hardsuit (No Prebreathing

Lunar/Mars Suit Prototype Designed for Lightweight, High Mobility Operational Environment: Fractional Gravity,

Dust


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AIR-LOCK, INC.EXTRA VEHICULAR ACTIVITY SUPPORT

DESIGN & MANUFACTURING EXPERTISE

-GEMINI

Air-Lock's design and manufacturing expertise was

directed towards supplying Gemini Suit Hardware, whichincluded Glove and Helmet Disconnects, Wrist Bearings as

well as Oxygen and Biomedical Connectors.

- APOLLO/SKYLAB

Air-Lock designed and manufactured all of the suit

hardware for the Apollo program. Additionally, when the need

became apparent in the beginning of the Apollo Program for

an advanced helmet. Air-Lock using'lR&D funds, over a 12

month period, designed and fabricated the equipment required

to manufacture polycarbonate helmets. This R&D effort

produced functional helmets which were flown on all of the

Apollo and Skylab missions. They are still manufacturing

these helmets today in support of the Shuttle Program.

- SHUTTLE

All of the Wrist, Arm, Scye and Waist Bearings,

Wrist Disconnects, Helmet Assemblies, Suit Side Neck Ring

Assemblies. Waist Disconnect (Body Seal Closure), EWA

(Extra Vehicular Visor Assembly) and many of the valve, gas

and electrical connectors currently used on the Space Shuttle

were designed and manufactured by Air-Lock.

ADVANCED EVA R&D HARDWARE

JOINT NASA/AIR-LOCK EFFORTS

Experimental space suit proto-types were designedand manufactured by Air-Lock for both the Johnson Space

Center and the Ames Research Center. In 1977, Air-Lock

designed and manufactured a Bi-planar suit closure for the

Ames Research Center. Over that past twenty years, All of the

Hard Upper Torso (HUTs) suits made for NASA, including

the Space Shuttle Suit, the ILC ZPS, ZPS Mark III, and the

Ames AX5, have closure systems designed and manufactured

by Air-Lock. In 1987 the high costs associated with machining

a HUT from a solid aluminum billet and the long lead times

associated with the hand lay up of fiberglass epoxy HUT

assemblies, prompted Air-Lock into using IR&D funds to

independently developed a Iow cost HUT by utilizing

investment casting technology. This

process was used to produce the Cast Aluminum MK I

HUT and Hatch which was delivered to Lockheed in 198

This technology gained the interest of NASA and in tur

they directed Hamilton Standard to purchase a Shutt

compatible unit from Air-Lock. A second cast aluminuHUT was furnished to Hamilton Standard in 1990. Th

HUT, a proto-type for the Shuttle EMU, is still successfull

being used in the WETF at NASA/JSC.

In 1990, in an unsolicited proposal, Air-Locattempted to convince NASA to consider an advanceIow cost solution to the 'pivoted shoulder" problemThey submitted a pivotless planar HUT model with nearm hole geometry to NASA and Hamilton StandardAs a direct result of this submission, the Shuttprogram is now replacing all Shuttle pivoted flight HUTwith planar HUTs.

NASA became interested in a developmeeffort for overall weight reduction of future HUstructures. In 1990, Air-Lock independently establisheon-site capabilities to support the fabrication of carbofiber/graphite composite hardware. In 1991 NASselected Air-Lock as the sole source for the design anfabrication of a carbon composite rear entry HUTUnder a January 1992 CPFF contract to NASA, AiLock designed, manufactured, tested and delivered thall composite Bi-planar rear entry HUT/Hatcassembly. This HUT is currently in use in JSCAdvanced Suit Laboratory.

From the beginning of the Shuttle program, AiLock's ideas have consistently contributed to thimprovement of the hardware used on the Shuttle SuAssembly. These design improvements include thLow Torque Lip Seals, the cast aluminum Shuttle HUTthe Acme Threaded Sizing Elements, (used in the Arand LTA of the SSA), and the current In-suit Drink BaValve Assembly.

In 1994 Air-Lock began a joint IR&D programwith Deposition Research Laboratory, Inc., to developenvironmentally robust Sun Visor coating which alshad exceptional optical/thermal properties. This coatindesign was subsequently delivered to NASA and hasince flown on STS-76, 79, 86, 88, and 90. This coatindesign has been certified for flight and replaced thprevious Sun Visor design in April 1999.


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Extravehicular Mobility Unit (EMU)

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