countdown nasa space shuttles and facilities

8/7/2019 Countdown NASA Space Shuttles and Facilities

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National Aeronautics and Space Administration

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wn!

NASA Space Shuttles and Facilities


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The rst fight o the commercially developed SPACEHAB laboratory module begins with the fawless lito o the Space Shuttle Endeavour rom

Launch Pad 39B on June 21, 1993.

Countdown c InformationSummary


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Space Shuttles

NASA explores or answers that power our uture.Te space shuttle is NASAs reusable manned spacevehicle designed or the transport o people, spacecraand equipment to and rom the International Space Sta-tion. Te shuttle comprises three major ight elements:

1) Te orbiter, which is a reusable delta-winged space-plane, is about the size and shape o a DC-9 jet, with threereusable liquid-ueled main engines. It has a design lie o100 missions.

Te original eet in the order the orbiters were rstown are Columbia , OV-102, (1981); Challenger, OV-099, (1983); Discovery, OV-103, (1984); Atlantis, OV-104,(1985); and Endeavour, OV-105, (1992). Challenger wasdestroyed Jan. 28, 1986, during launch. Columbia waslost Feb. 1, 2003, while returning rom research mission

SS-107.Te orbiters are named aer pioneering sea vesselsthat established new rontiers in research and exploration.Only the orbiters have names, and an orbiter alone is not aull space shuttle.

2) Te external tank contains liquid hydrogen andliquid oxygen or the orbiters three main engines. It is theonly major element not recovered and reused.

3) wo solid rocket boosters, called SRBs, lled withsolid propellant burn in unison with the orbiters enginesat lio. Tey are designed or reuse on at least 20 mis-

sions, and are recovered at sea aer separation.Te space shuttle has remained the only NASA-op-

erated manned space vehicle into the 21st century.In addition to its normal workload o scientic satel-

lites and space science missions, the shuttle eet o threevehicles is the primary transport into orbit or the seg-ments o the International Space Station.

Russia has used its own vehicles to launch some spacestation components, and so may some o the otherpartners.

Te space station has been continuously mannedsince Nov. 2, 2000. Prior to that time, America had main-tained a continuous presence in space on Space StationMir by an agreement with Russia that allowed astronautsto rotate turns o duty.

Te rst space shuttle li ed o rom Pad A onLaunch Complex 39 at Kennedy Space Center on April12, 1981.

Aer a two-day, test-ight mission that veried theability o the orbiter Columbia to unction in space, itlanded at Edwards Air Force Base in Caliornia. Tevehicle was piloted by John Young and Robert Crippen.Te SS-1 mission marked the rst time that a new spacevehicle carried a crew on its initial ight.

An assembled space shuttle is approximately 184 eet(56 meters) long, 76 eet (23 meters) high to the tip o theorbiters vertical tail , and 78 eet (24 meters) wide, mea-sured across the orbiters wingt ips. Lio weight is usuallyabout 4.5 million pounds (2,041,200 kilograms).

An orbiters three liquid-ueled engines drawing

propellants rom the external tank and the two solidpropellant rocket boosters burn simultaneously or therst two minutes. ogether, they produce almost 7 millionpounds (31.1 million newtons) o thrust at lio.

Aer two minutes o ight, a space shuttle reaches analtitude o 32 miles (51 kilometers) and the boosters haveburned all their propellant. Tey then detach and para-chute into the ocean. wo waiting ships recover them orreurbishment and reuse on later missions.

Te orbiter and external tank continue on towardEarth orbit. When the orbiters main engines cut o, the

external tank is jettisoned, to re-enter the atmosphere andbreak up over a remote ocean area.

On most missions, the orbiter continues to coast,while still gaining altitude rom the initial thrust, until itreaches the other side o the Earth rom where the exter-nal tank was discarded.

Ten the on-board orbital maneuvering engines reto place the vehicle in a near circular, low-Earth orbit.Most operational missions last rom seven to 10 days,though two weeks or more are not uncommon.

When the mission has been completed, the orbiterre-enters the atmosphere and returns to Earth, gliding toan unpowered landing at the Shuttle Landing Facility, orEdwards AFB i bad weather or other circumstances pre-clude landing at Kennedy.

Countdown 1 InformationSummary


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Solid propellants are stable and easily storable. Unlikeliquid-propellant engines, though, a solid-propellant mo-tor cannot be shut down. Once ignited, it will burn untilall the propellant is exhausted.

Solids have a variety o uses or space operations.Small solids oen power the nal stage o a launch vehicle,or attach to payload elements to boost satellites and space-cra to higher orbits.

Medium solids such as the payload assist module, orPAM, and the inertial upper stage, or IUS, provide theadded boost to place satellites into geosynchronous orbitor on planetary trajectories.

Te PAM-DII provides a boost or space shuttle pay-loads. Te IUS goes on the space shuttle.

Te space shuttle uses the largest solid rocket motorsever built and own. Each reusable booster contains 1.1million pounds (453,600 kilograms) o propellant, in theorm o a hard, rubbery substance with a consistency like

that o the eraser on a pencil.Te our center segments are the ones containingpropellant. Te uppermost one has a star-shaped, hollow

channel in t he center, extending rom the top to abouttwo-thirds o the way down, where it gradually roundsout until the channel assumes the orm o a cylinder. Tisopening connects to a similar cylindrical hole throughthe center o the second through ourth segments. Whenignited, the propellant burns on all exposed suraces, romtop to bottom o all our segments.

Since the star-shaped channel provides more exposedsurace than the simple cylinder in the lower three seg-ments, the total thrust is greatest at lio, and gradually

decreases as the points o the star burn away, until thatchannel also becomes cylindrical in shape. Te propellantin the star-shaped segment is also thicker than that in theother three.

A solid propellant always contains its own oxygensupply. Te oxidizer in the shuttle solids is ammonium per-chlorate, which orms 69.93 percent o the mixture. Teuel is a orm o powdered aluminum (16 percent), with aniron oxidizer powder (0.07 percent) as a catalyst. Te bind-er that holds the mixture together is polybutadiene acrylicacid acrylonitrile (12.04 percent). In addition, the mixturecontains a n epoxy-curing agent (1.96 percent). Te binderand epoxy also burn as uel, adding thrust.

Te specic impulse o the space shuttle solid rocketbooster propellant is 242 seconds at sea level and 268.6seconds in a vacuum.

Atlantis is in the Vehicle Assembly Building, where it has been

stacked with the external tank and solid rocket boosters.

A solid rocket

booster is

seen on

the mobile

launcher

platorm aspart o the

stack or

Discovery

and shuttle

mission

STS-92.



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Kennedy Space Center is the primar y NASA centeror the test, checkout and launch o space shutt levehicles and their payloads, as well as the turnaround oorbiters between missions. It is the primary landing site

or the shuttle.Manned space shuttles launch rom KennedysLaunch Complex 39, located on Merritt Island, Fla., justnorth o Cape Canaveral. Te Launch Complex 39 acili-ties originally supported the Apollo lunar landing pro-gram. From 1967 to 1975, 12 Saturn V/Apollo vehicles,one Saturn V/Skylab workshop, three Saturn 1B/Apollovehicles or Skylab crews , and one Saturn 1B/Apollo orthe joint U.S.-Soviet Apollo-Soyuz mission ew intospace rom Launch Complex 39.

Tese acilities underwent modications to process

and launch the space shuttle. Modiying existing acilitieswas ar less expensive than building all new structures.

Tere were two major new additions a specialrunway to land returning orbiters and an orbiter checkouthangar called the Orbiter Processing Facility. During the1980s and 1990s, several new acilities were added or solidrocket booster processing, shuttle logistics, orbiter modi-cation and reurbishment, and repair and nal manuac-ture o thermal protection system materials.

Shuttle Landing Facility

When an orbiter lands at the Kennedy Space Center,it touches down on one o the worlds longest runways.Te concrete Shuttle Landing Facility is located north-

west o the Vehicle Assembly Building on a northwest/southeast alignment.

Navigational aids on the ground and on board theorbiter help to direct it to a smooth landing. A microwavescanning beam landing system guides the nal approachand brings the orbiter to the designated point on therunway.

Landings may be made rom the northwest to south-east (Runway 15) or rom the southeast to northwest(Runway 33).

Unlike conventional aircra, the orbiter lacks propul-sion during the landing phase. Its high-speed glide mustbring it in or a landing perectly the rst time there isno circle-and-try-again capability. Te landing speed othe orbiter ranges rom 213 to 226 miles (343 to 364 kilo-meters) per hour. A large drag chute helps slow the orbiterduring rollout, greatly reducing wear on the wheel brakes.

Te runway is about twice the length and width othose at most commercial airports. Te landing strip isconcrete and approximately 15,00 0 eet (4,572 meters)long. It has an asphalt overrun, 1,000 eet (305 meters)

long, at each end.

Facilities and Operations

Space Shuttle Endeavour is towed toward the mate-demate device ollowing landing on runway 15 at KSCs Shuttle Landing Facility atop a

modied Boeing 747 shuttle carrier aircrat.



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Te overruns have been strengthened so that theyalso could support the weight o a shuttle orbiter whenlanding. Te runway is 300 eet (91.4 meters) wide, with50-oot (15-meter) shoulders, also asphalt, which havebeen strengthened to support an orbiter.

Te runway is 16 inches (40.6 centimeters) thick atthe center, and slopes downward 24 i nches (61 centime-ters) both ways to the asphalt on each side. Te concrete

was originally cut with grooves, each 0.25 inch (0.63 cen-timeter) wide and deep, and 1.25 inches ( 3.2 centimeters)apart, rom the center to the edges o the asphalt. Tegrooves and slope were thought to provide a very eec-tive way to shed water, helping to prevent hydroplaningin wet weather. Te grooves also provided a skid-resistantsurace.

Te rst 3,500 eet (1,067 meters) at each end werelater ground down to remove the grooves because o highabrasion levels on the tires at touchdown. Also, improve-

ments were made to the landing zone light xtures. In1994, the entire runway surace was abraded to a smoothertexture to urther reduce tire wear.

A 550-by-490-oot (168-by-149-meter) aircra park-ing apron, or ramp, is located at the southeastern end othe runway. On the northeast corner o the ramp is themate/demate device which attaches the orbiter to or lisit rom the Shuttle Carrier Aircra during erry

operations. Tere are movable platorms or access tosome orbiter components.

Te mate/demate device can li up to 230,000pounds (104,328 kilograms) and withstand winds o up to125 miles (201 kilometers) per hour.

A diesel-driven towing tractor brings the orbiter toits next stop aer landing, the Orbiter Processing Facil-ity. Ground-cooling and air-purging transporters are still

hooked up to the orbiter and t ravel behind the orbiterduring the tow.

Orbiter Processing Facility

An orbiter is towed to the Orbiter Processing Facilitywithin hours o its arrival, either aer landing at Kennedyor returning aboard a erry ight on the shuttle carrieraircra.

Te acility has three almost identical high bays, eacho which is 197 eet (60 meters) long, 150 eet (46 meters)

wide, 95 eet (29 meters) high, and encompasses a 29,000-square-oot (2,694 square-meter) area. A low bay connectshigh bays 1 and 2 . It is 233 eet (71 meters) long, 97 eet (30meters) wide and nearly 25 eet (eight meters) high.

High bay 3, built last, is located to the north and easto the rst t wo; it also has an adjacent low bay. Annexesand portable buildings provide additional shop and

Processing or a mission begins when an orbiter is towed into one o three Orbiter Processing Facility bays at KSC.



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ofce space. Each high bay comes equipped with a 30-ton(27-metric-ton) bridge crane with a hook height o ap-proximately 66 eet (20 meters). Platorms, a main accessbridge and two rolling bridges with trucks provide accessto various parts o the orbiter. Te trucks have a telescop-ing arm with rotatable buckets to hold workers. Te highbays have an emergency exhaust system. Te low bay con-tains areas or electronic, mechanical and electrical equip-ment, a communications room, ofces and supervisorycontrol rooms. All bays have re protection systems.

In addition to routine post-ight servicing and check-out, many o the vehicle modications needed or utureight requirements, or to enhance vehicle perormanceand correct deciencies, are perormed in the OrbiterProcessing Facility.

Spacecra or payloads processed through checkoutin a horizontal position, usually the larger ones such asspace station elements, are installed in the orbiter in this

acility. Spacecra or payloads handled in a vertical posi-tion normally are installed at the launch pad.Aer processing, the orbiter is usually towed into

the Vehicle Assembly Building transer aisle through thelarge door at the north end o the high bay to acilitatemating with the solid rocket booster/external tank stack.

Thermal Protection

System Facility

A thermal protection system, composed o a networko tiles, gap llers and insulation blankets, protects theexterior o each orbiter rom the searing heat o launchand re-entry, and the cold soak o space. Tese materialscan sustain damage during a ight and must be inspected,

repaired, or sometimes replaced or the next mission.Repair and nal manuacture o the thermal protec-tion system materials takes place in the two-story, 44,000-square-oot (4,088-square-meter) Termal ProtectionSystem Facility. It is located across the street rom theOrbiter Processing Facility bays 1 and 2.

Logistics Facility

Te modern 324,6 40-squa re-oot (30,159-square-me-ter) Logistics Facility is located south o the Vehicle As-

sembly Building. It contains about 150,000 space shuttlehardware parts and about 330 NASA and contractorworkers.

An unusual eature o the Logistics Facility is thestate-o-the-art parts retrieval system, which has automat-ed handling equipment to nd and retrieve specic parts.

Launch Equipment

Test Facility (LETF)

Te testing site or launch-critical ground supportsystems and equipment such as the orbiter access arm,external tank gaseous oxygen vent arm, external tank ventline, tail service masts and umbilical systems, and SRBholddown posts. It is designed to simulate launch vehicleevents such as movement rom wind, orbiter ignition andlio, eects o solar heating and cryogenic shrinkage.

The Multi-Payload

Processing Facility (MPPF)

Te Multi-Payload Processing Facility, or MPPF, wasconstructed in 1995 and is located in the Industrial Area.Te acility is 19,647 square eet (1,825 square meters)in area and can accommodate one or more payloads inprocessing at the same time depending on their size. Teacility supports the checkout assembly payload process-ing program. Te MPPF has a high bay and a low bay andis equipped with a 20-ton overhead crane. In addition, theMPLM Access Certication Equipment , or MACE,training unit is located inside the MPPF. Te MACE is anexact replica o the U.S .-made Unity module on the space

Atlantis rolls to the Vehicle Assembly Building.



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station and is used to support training activities or theSpace Station Processing Facility.

Space Station Processing

Facility (SSPF)

Tis is the central preight checkout and processingpoint or ight hardware elements o the International

Space Station. Known as the SSPF, it is three stories tallwith 457,000 square eet (42,455 square meters) o space,including 63,000 square eet (5,853 square meters ) dedi-cated to payload processing with a high bay and interme-diate bay.

Te test, control and monitor system, or CMS,controls prelaunch testing and checkout or space sta-tion elements. Te SSPF also includes communicationsand electrical control areas, laboratories, logistics stagingareas, operational control rooms, ofce areas and a cae-

teria. A 5,000-square-oot ( 464 square-meter) airlock isadjacent to the processing area, both o which are class-100,000 clean work area environments.

Vertical Processing Facility (VPF)

Tis 26,940 square-oot ( 2,503 square-meter) acil-ity processes and integrates vertical payloads and upperstages. It contains cargo integration test equipment , orCIE, or verication o orbiter/payload interaces and isan environmentally controlled class-100,000 clean workarea high bay and airlock. It has a high-bay ceiling heighto 105 eet (32 meters) with usable oor space o 10,153square eet (943 square meters), two bridge cranes withcombined li capacity o 35 tons (31.7 metric tons) and amonorail crane o 10 tons (.1 metric ton) that services theairlock. Its six xed platorms or spacecra handling areserviced by a 2-ton (1.8-metric-ton) hoist.

Solid Rocket Booster

Processing Facilities

Aer the space shuttle launches, the two solid rocketboosters burn out and jettison about two minutes intothe ight. Huge parachutes lower them into the AtlanticOcean where special recovery vessels retrieve and towthem back to a dock at Cape Canaveral Air Force Station.

Solid Rocket Booster Disassembly Facility: Tearea in and around Hangar AF and the hangar build-ing itsel together make up t he Solid Rocket BoosterDisassembly Facility. Special handling equipment lo-

cated behind Hangar AF lis the solid rocket boost-ers rom the water. Tere, they undergo an initialwashing. Each booster disassembles into our mainsegments and a skirt and orward skirt assemblies.Te main casing segments are cleaned, taken backto Launch Complex 39 at Kennedy and placed onrailroad cars or shipment to the manuacturer wherethey are reloaded with propellant.

Solid Rocket Booster Assembly and Refurbish-ment Facility: Reurbishment and subassembly oinert solid rocket booster hardware, including theorward and a skirt assemblies, takes place in thisacility, located south o the Vehicle Assembly Build-ing. Tis complex has seven buildings manuactur-ing, engineering and administration, service, hot re

testing, structures storage, modular ofce and chilleracility. Te three-level manuacturing buildingincludes an automated checkout system, an 80-by-200-oot (24-by-61-meter) high bay, two 15-ton (14-metricton) bridge cranes, and three overhead gantryrobots; the latter are among the worlds largest.

Rotation Processing and Surge Facility: Locatedjust north o the Vehicle Assembly Building, this

The truck delivering part o the equipment to be used on mission

STS-109 moves into the Vertical Processing Facility at Kennedy.



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acility receives new and reloaded solid rocket boostersegments shipped by rail rom the manuacturer.Te complex includes a processing building and twosurge buildings. Inspection, rotation and a boosterbuildup occur in the processing building. Completeda skirt assemblies rom the Assembly and Reur-bishment Facility integrate here with the booster asegments. Te two nearby surge buildings (so namedbecause they hold the surge o new booster seg-ments) store the solid rocket booster segments untilthey are moved to the Vehicle Assembly Building orintegration with ight-ready components.

Parachute Refurbishment Facility: Originallybuilt to process parachutes used in the Geminimanned space program, this acility in the IndustrialArea has been modied or the space shuttle. Tetwo vessels that recover the solid rocket boosters alsoretrieve the parachutes rom the ocean, hauling them

in on large reels. Tese reels are taken to this acility,where the parachutes are washed, dried and stored incanisters or eventual reuse.

Vehicle Assembly Building: Te solid rocketbooster segments are integrated here into completeight sets, mated with the external tank and then theorbiter beore being moved to the launch pad.

External Tank

Te external tank arrives by barge rom its manuac-turing site in Louisiana. O-loaded at the Launch Com-plex 39 turn basin, it travels horizontally to the VehicleAssembly Building. Tere, it is processed and stored ina vertical storage or checkout cell until mated with theother space shuttle ight elements.

When loaded, the external tank is the largest andheaviest element o the space shuttle. Besides containingand delivering propellants to the main engines, it servesas the structural backbone o the shuttle by absorbing thethrust loads during launch.

Te tank has three major components: the orwardliquid oxygen tank, an unpressurized intertank that con-tains most o the electrical components and joins the twopropellant-lled tanks, and the a liquid hydrogen tank.

Te entire external tank is approximately 154 eetlong (47 meters) and 28 eet (8.5 meters) in diameter. Te

liquid oxygen and hydrogen eed into the tank at thelaunch pad. Tese cryogenic propellants uel the orbitersthree main engines during lio and ascent.

Aer the shuttle main engines shut down, the exter-nal tank separates rom the orbiter and ollows a ballistictrajectory into the Indian Ocean. It is the only majorspace shuttle component that is not recovered and reused.

Ater its arrival by barge, an external tank is transported to theVehicle Assembly Building.



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External TankLength:................154.2feet(47meters)

Diameter:.............27.5feet(8.4meters)

LoadedWeight:...1,647,677pounds(745,555kilograms)

EmptyWeight:.....58,500pounds(26,470kilograms)

LOXTank:............Maximum143,351gallons(542,641liters)

LH2Tank:.............Maximum385,265gallons(1,458,382liters)

(AllFiguresApproximate)

Solid RocketBoosterLength:..................149.2feet(45.5meters)

Diameter:..............12.2feet(3.7meters)

Weight:..................1.38millionpounds(6.3millionkilograms)

LiftoffThrust..........Each2.9millionpounds(12.9millionnewtons)

(AllFiguresApproximate)



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Space Shuttle Main Engine

Processing Facility (SSMEPF)

Newly arrived space shuttle main engines, deliveredby truck rom Stennis Space Center in Mississippi aertest ring, o-load in the Space Shuttle Main EngineProcessing Facility, known as the SSMEPF, in the OrbiterProcessing Facility No. 3 Annex.

Te SSMEPF is a 33,500-square-oot acility with sixvertical stands and a 10-ton crane in the low bay and a 15-ton crane, drying bay and GSE storage in the high bay.

Tis processing acility can support engine buildingand engine processing post-ight (disassembly and reas-sembly, checkout and testing). Te engines go to the OPFor installation.

Te SSMEPF also supports engine removal opera-tion and preparation or shipment back to Stennis or testring, or to the manuacturer in Caliornia or reurbish-ment.

A cluster o three main engines provides the primarypropulsion or the orbiter and helps to steer the shuttle.Te liquid-hydrogen/liquid-oxygen propellant enginesignite on the ground and work in parallel with the SRBsduring the initial ascent. Aer booster separation, the en-gines continue to operate or several minutes. Tey are theonly reusable engines.

Vehicle Assembly Building (VAB)

At the heart o Launch Complex 39 is the huge Vehi-

cle Assembly Building, one o the largest buildings in theworld and the last stop or the shuttle beore the launchpad. It covers a ground area o about eight acres (3.24hectares) and has a volume o approximately 129,482,000cubic eet (3,884,460 cubic meters). Te VAB is 525 eet(160 meters) tall, 716 eet (218 meters) long, and 518 eet(158 meters) wide.

Te structure can withstand winds o up to 125 miles(201 kilometers) per hour. Te oundation rests on morethan 4,200 steel pipe pilings, each 16 inches (40.6 centime-ters) in diameter and driven down to bedrock at a depth o160 eet (49 meters).

Te high bay area is 525 eet tal l (160 meters) and thelow bay area is 210 eet (64 meters) tal l. A nort h-southtranser aisle connects and transects the two bay areas.

Shuttle main engine maintenance takes place in thelow bay, which also serves as a holding area or SRB or-ward assemblies and a skirts.

Facing east are high bays 1 and 3 where integrationand stacking o the complete space shuttle occurs in a

vertical position on the mobile launcher platorm. Facingwest are high bays 2 and 4 where external tank checkoutand storage takes place. High bay 2 also serves as a saehaven or a shuttle in the event o extreme weather condi-tions, such as a hurricane.

Te VAB has more than 70 liing devices, includingtwo 325-ton (295-metric-ton) cranes.

During space shuttle buildup operations inside theVAB, SRB segments are transerred rom nearby assem-bly and checkout acilities, hoisted onto a mobile launcherplatorm in high bays 1 or 3, and mated to orm two com-plete boosters.

Aer checkout and inspection in high bays 2 or 4, theexternal tank transers to high bays 1 or 3 to be attachedto the SRBs. Te orbiter, the nal element, gets towedrom the Orbiter Processing Facility to the VABs transeraisle, raised to a vertical position by overhead cranes, low-ered onto the mobile launcher platorm, and mated to theexternal tank.

A 175-ton bridge crane in the Vehicle Assembly Building

lits Discovery to move it into high bay 3 or mating with the

external tank and solid rocket boosters.



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With the assembly and checkout operations com-plete, the huge outer doors o the high bay open to permitthe crawler-transporter to enter and move under the mo-bile launcher platorm holding the assembled shuttle. Tehigh bay doors are 456 eet (139 meters) high. Te lowersection is 152 eet (46 meters) wide and 114 eet (35 me-ters) high, with our door panels that move horizontally.

Te upper door is 342 eet (104 meters) high and 76

eet (23 meters) wide, with seven door panels that movevertically.

Launch Control Center (LCC)

I the Vehicle Assembly Building is the heart oLaunch Complex 39, then the Launch Control Center,known as the LCC, is its brain. Te center is a our-storybuilding connected to the east side o the Vehicle Assem-bly Building by an elevated, enclosed bridge.

Te LCC contains two primary and one backup

control rooms. Each is equipped with the launch process-ing system an automated computer-operated system which monitors a nd controls shuttle assembly, checkout

and launch operations.Largely because o the launch processing system, the

countdown or a space shuttle launch (excluding built-inholds) takes only about 43 hours, compared to more than80 hours needed or the earlier Apollo/Saturn ights.

Also, use o the launch processing system requiresonly approximately 225-230 people in the ring roomcompared to about 450 people needed or Apollo

manned missions.Mission responsibility transers to the Mission Con-

trol Center at Johnson Space Center in Houston whenthe solid rocket boosters ignite at lio.

Transportable Equipment

and Facilities

Te mobile launcher platorm , or MLP, is a two-story steel structure that provides a transportable launchbase or the space shuttle. First used in the Apollo/Saturn

program, the MLP underwent modications or theshuttle.

The Launch Control Center aces both launch pads.



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Te main body o each MLP is 25 eet (7.6 meters)high, 160 eet (49 meters) long, and 135 eet (41 meters)wide. At their park ing sites north o the Vehicle AssemblyBuilding, in the Vehicle Assembly Building high bays andat the launch pads, the mobile launcher platorms rest onsix pedestals 22 eet (6.7 meters) high.

Unloaded, an MLP weighs about 8.23 millionpounds (3.73 million kilograms). With an unueled shut-tle aboard, it weighs about 11 million pounds (5 millionkilograms).

Te main body o the MLP provides three openings two or the ex haust o the solid rocket boosters and oneor the exhaust o the main engines.

Tere are two large devices called tail service masts,one on each side o the main engines exhaust hole. Temasts provide several umbilical connections to the orbiter,including a liquid-oxygen line through one and a liquid-hydrogen line through another.

Tese cryogenic propellants eed into the externaltank rom the pad tanks via these connections. At launch,the umbilicals pull away rom the orbiter and retract intothe masts, where protective hoods rotate closed to shieldthem rom the exhaust ames.

Each tail service mast assembly is 15 eet (4.6 meters)

long and 9 eet (2.7 meters) wide, and rises 31 eet (9.4 me-ters) above the MLP deck. Other umbilicals carry heliumand nitrogen, as well as ground cooling, purge air, electri-cal power and communications links.

Eight attach posts, our on the a skirt o each SRB,support and hold the space shuttle on the MLP. Teseposts t on counterpart posts located in the MLPs twosolid rocket booster support wells. Te space vehicle dis-connects rom the MLP by explosive nuts that release thegiant studs linking the solid rocket attach posts with theMLP support posts.

Each mobile launcher platorm has two inner levelscontaining electrical, test and propellant-loadingequipment.

A crawler-transportermoves a ully assembled spaceshuttle, mounted on a mobile launcher platorm, rom theVehicle Assembly Building to the launch pad. Te hugetracked vehicles, originally used during the Apollo era,

underwent modications or the shuttle.Te two crawlers are about 20 eet (6.1 meters) high,131 eet (40 meters) long, and 114 eet (34.7 meters) wide about the size o a baseball diamond. Each one weighsabout 6 million pounds (2.7 million kilograms) unloaded.A crawler has eight tracks, each with 57 shoes, or cleats,

A mobile launcher platorm makes a test run on a crawler-transporter to the launch pad. Rising above the platorm are the tail service masts.



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each weighing approximately 1 ton (907 kilograms).With a space shuttle aboard, the crawler can move

at a maximum speed o about 1 mile (1.6 kilometers) anhour. Unloaded, it has a maximum design speed o 2 miles(3.2 kilometers) an hour, but in practice usually moves atthe loaded speed.

Te crawler has a leveling system designed to keepthe top o the space shuttle vertical while negotiating the

5-percent grade leading to the top o the launch pad. Also,a laser docking system provides almost pinpoint accuracywhen the crawler and MLP are positioned at the launchpad or in the Vehicle Assembly Building.

wo 2,750-horsepower diesel engines power eachcrawler. Te engines drive our 1,000-kilowatt generatorsthat provide electrical power to 16 traction motors. Op-erators in cabs on either end steer the giant vehicle.

Te crawlerwayis a 130-oot-wide (39.6-meter)roadway almost as broad as an eight-lane reeway. Te

crawler-transporters use this or their more than 3-mile(4.8-kilometer) trek to one o the launch pads rom theVehicle Assembly Building.

Te crawlerway consists o t wo 40-oot- (12-meter-)wide lanes, separated by a 50-oot- (15-meter-) wide me-dian strip. Te crawlerway has our layers to support thehuge weight. Te crawler, MLP and space shuttle with

empty external tank weigh about 17 mil lion pounds (7.7million kilograms). Te top layer o the crawlerway is rivergravel about 8 inches (20.3 centimeters) thick on curvesand 4 inches (10.2 centimeters) thick on straight-awaysections. Te other layers in descending order are 4 eet(1.2 meters) o graded, crushed stone; 2 .5 eet (0.76 meter)o select ll; and 1 oot (0.30 meter) o compact ll. Tejourney rom the Vehicle Assembly Building to one o thelaunch pads several miles away takes several hours.

Te payload canisterholds payloads in transit romvarious processing or assembly acilities to the launch pad(or vertical ly insta lled payloads) or to the Orbiter Pro-cessing Facility (or horizontally installed payloads).

Each environmentally controlled canister can carrypayloads up to 15 eet (4.6 meters) in diameter and 60 eet(18.3 meters) long, matching the capacity o the orbiterpayload bay. Maximum payload weight is approximately65,000 pounds (29,484 kilograms).

Te payload canister transporteris a 48-wheel, sel-propelled truck that can transport the canister and itshardware either in a vertical or a horizontal position. It is65 eet (19.8 meters) long and 23 eet (7 meters) wide, witha atbed that can be lowered and raised rom about 5 eet(1.5 meters) to 7 eet (2.1 meters) i required.

The crawler-transporter (6 million pounds) can lit the space shuttle on its mobile launcher platorm (at a combined weight o about

11 million pounds) and move it to and rom the launch pads. A crawler has eight tracks, each o which has 57 shoes or cleats. Each shoe

weighs approximately 1 ton.



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Independently steerable wheels permit the transport-er to move orward, backward, sideways and diagonally, orturn on its own axis like a carousel. Diagonally opposedoperator cabs are located on each end o the truck.

A diesel engine powers the transporter. Inside aspacecra acility, it runs on an electric motor. Fully load-ed, its top speed is about 5 miles (8 kilometers) per hour.But it can creep as slowly as 0.25 inch (0.635 centimeter)

per second, or approximately 0.014 mile (0.022 kilometer)per hour, or payloads that require precise handling.

Launch Pads 39A and 39B

Launch Pads A and B at Complex 39 were originallydesigned or the Apollo program. Tey are octagonal inshape and virtually identical in size. Each covers about0.25-square mile (0.65-square kilometer) o land, con-tained within a high chain-link ence.

Space shuttles launch rom the top o the concretehardstand, which measures 390 eet by 325 eet (119 me-ters by 99 meters). Te Pad A stand has an elevation o48 eet (14.6 meters) above sea level; Pad B, 55 eet (16.8meters). Tere are six permanent and our extensible ped-estals at each pad to support the MLP.

Lighting is provided by ve clusters o xenon high- in-tensity searchlights (or a total o 40 searchlights) around

the pad perimeter.Each pad base required 68,000 cubic yards (52,000

cubic meters) o concrete. Te ramp leading up to the padsurace is inclined at a 5-percent grade.

Te two pads were heavily modied rom theirApollo/Saturn V conguration to launch space shuttles.Te upper portions o two o the three Saturn V launchumbilical towers were removed rom the mobile launchers(which became mobile launcher platorms aer this andother changes) and instal led at each pad, to become xed

service structures, or FSS.A rotating service structure, or RSS , whichreplaces the movable gantry in older designs, was built ateach pad. And the movable Saturn V ame deector ineach ame trench was replaced with two joined and an-chored shuttle ame deectors.

Te xed service structure is located on the northside o each pads hardstand. It is an open rameworkstructure about 40 eet (12.2 meters) square. Tere are 12work levels at 20-oot (6.1-meter) intervals.

Te height o the struct ure to the top o the tower is

247 eet (75 meters), while the distance to the top o theberglass lightning mast is 347 eet (106 meters).

Te FSS has three service arms:

1. Orbiter Access Arm. Tis arm swings out to thecrew access hatch on an orbiter, to provide entry orpersonnel. Te outer end o this arm supports a smallroom, commonly called the White Room, whichcan hold up to six persons.

A special White Room crew assists each astronautcrew in entering the space shuttle and secures the

hatch. Tis arm remains in the extended positionuntil 7 minutes and 24 seconds prior to launch, toprovide an emergency exit or the crew should onebe needed. It is 65 eet (19.8 meters) long, 5 eet (1.5meters) wide, and 8 eet (2.4 meters) high.

Te orbiter access arm is attached to the FSS at the147-oot (44.8-meter) level. In an emergency, thisarm can be mechanically or manually repositioned

The payload canister transporter can transport payloads in

the canister either vertically or horizontally. On the launch pad

(above), the canister is ready to be lited up into the Payload

Changeout Room on the rotating service structure.



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in about 15 seconds. It is covered with solid panels orre protection, as well as a water spray system. Tearm is also used or access to the mid-deck or late-in-the-count stowage o science experiments.

2. External Tank Hydrogen Vent Line andAccess Arm. Tis system consists o two parts, aretractable access arm and a xed support structure.

It provides a means to mate the external umbilicalsrom the FSS to the tank, and access to the tank inte-rior. Te access arm supports small helium and nitro-gen lines and electrical cables, all o which are locatedon an 8-inch-(20 centimeter-) diameter hydrogenvent line. Te arm, which rotates 120 degrees to thestowed position in about three minutes, is retractedseveral hours beore launch, leaving the umbilicalsattached.

At SRB ignition, the umbilicals are released andretracted 33 eet (10.1 meters) into a latched positionby a system o counterweights, where a curtain o

sprayed water protects them rom the engine ames.Tis activity takes just two seconds. Te arm is 48eet (14.6 meters) long, and attached at the 167-oot(51-meter) level .

3. External Tank Gaseous Oxygen Vent Arm.Tis retractable arm supports a vent hood, common-ly called the beanie cap, that vacuums away the very

cold liquid oxygen vapors as they boil o rom thetop o the external tank. It also supports associatedsystems such as heated gaseous nitrogen lines, theliquid oxygen vapor ducts, and electrical wiring.

Te beanie cap is 13 eet (4 meters) in diameter, andthe arm that supports it is 80 eet (24.4 meters) long,5 eet (1.5 meters) wide, and 8 eet (2.4 meters) high.It attaches to the xed service structure between the207-oot (63-meter) and 227-oot (69-meter) levels.

When the beanie cap is swung into position on top

o the external tank prior to loading propellants, twoinatable accordion-type seals cover the liquid oxy-gen vent openings. A heated gaseous nitrogen purgeows into the seal cavity, warming the very coldliquid oxygen vapors enough to prevent them romcondensing into ice. I ice ormed, it could dislodgeand damage the tank, or orbiter insulation tiles andblankets, at lio. Te beanie cap lis to clear theexternal tank and the arm retracts starting 2 minutesand 30 seconds beore engine ignition.

Hypergolic Umbilical System. Tis carries hyper-golic uel and oxidizer, as well as helium and nitrogenservice lines, rom the xed service structure to thespace shuttle.

Te system also allows rapid connection o the linesto and disconnection rom the vehicle. Six umbilicalhandling units, manually operated and controlledat the pad, attach to the rotating service structure.Tese units are located to the right and le sides othe a end o the orbiter. Tey serve the orbital ma-neuvering system and reaction control system, as well

as the payload bay and the nose area o the orbiter.

Te rotating service structure provides protectionor the orbiter and access to the cargo bay or installationand servicing o payloads at the pad. It pivots through one-third o a circle, to 120 degrees, rom a retracted positionwell away rom the shuttle to where its payload changeoutroom doors meet and match the orbiter cargo bay doors.

The gaseous oxygen vent hood (at top), known as the beanie

cap, is located on the end o the highest swingarm attached to

the Fixed Service Structure.



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Tis structure rotates around a vertical hingeattached to one corner o the xed service structure. Tebody o the rotating service structure begins at the 59-oot (18-meter) level and extends to 189 eet (57.6 meters)above the pad oor, providing orbiter access platorms atve levels. Te hinge and a structural ramework on theopposite end support the structure. Tis ramework restson two eight-wheel, motor-driven trucks, which ride on

rails installed within the pad surace. Te rotating body is102 eet (31 meters) long, 50 eet (15 meters) wide and 130eet (40 meters) high.

Te primary purpose o the rotating service structureis to receive vertically installed space shuttle payloadswhile in the retracted position, rotate and install them inthe orbiter cargo bay.

Payload Changeout Room: Tisis the major ea-ture o the RSS. It is an enclosed, environmentallyclean White Room that supports payload delivery

and servicing at the pad and mates to the orbitercargo bay or vertical payload installation. Te envi-ronmental seals in the structure inate against thesides o the payload canister. Clean, temperature- andhumidity- controlled air purges the space betweenthe closed doors o the RSS and the canister.

Te canister and the RSS doors then close, the en-vironmental seal deates, and the canister lowersto the transporter to be taken o the pad. Te RSSrolls into position to enclose the orbiters payload bay,re-establishing the environmental seals and clean-airpurge.

Te payload is removed rom the canister and laterinstalled inside the orbiter cargo bay using the pay-load ground handling mechanism, or PGHM (pro-nounced pig-um). Five platorms are positioned atve levels to provide access to the payload when it isinstal led on the PGHM. Each platorm has extend-able planks that can be congured to accommodatea particular payload.

Orbiter Midbody Umbilical Unit: Tis providesaccess to and permits servicing o the miduselagearea o the orbiter. It extends rom the rotating ser-vice structure at levels ranging rom 158 to 176 eet(48 to 53.6 meters) above the pad surace, and is 22eet (6.7 meters) long, 13 eet (4 meters) wide and 20eet (6 meters) high. A sliding extension platorm anda horizontally moving, line-handling mechanism o-er access to the midbody umbilical door on the le

side o the orbiter. Liquid oxygen and liquid hydrogenor the uel cells, and gases such as nitrogen and he-lium, eed through this unit.

Aweather protection system at Pad A and Pad Bshields the orbiter rom windblown debris, heavy rainsand hail that could damage the cras thermal protectionsystem tiles and insulation blankets. Te rotating service

structure, which closes around the orbiter while on thepad, shields a considerable portion o the vehicle. Teweather protection system lls the gaps.

Metal doors that slide together between the orbitersbelly and the external tank provide protection or thelower portion o the orbiter. Tese doors, which measureup to 53 eet (16 meters) long and 38 eet (11.6 meters) tall,weigh up to 46,000 pounds (20,866 kilograms). Tey con-nect to the rotating service structure and the xed service

Two payloads the Canadian robotic arm or Space Station

Remote Manipulator System, and the Multi-Purpose Logistics

Module Raaello are moved into the payload changeout room

or mission STS-100.



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structure. Te doors move together rom opposite sideson wheeled anges that ride on steel beams.

An inatable seal that protects the top o the orbiterextends rom the payload changeout room, orming asemicircle covering 90 degrees o arc between the vehicleand the external tank. A series o 20 or more biold metaldoors, about 80 by 4 eet (24.4 by 1.2 meters) in size, oldout rom the payload changeout room on the rotating

service structure to cover the side areas between the exter-nal tank and the orbiter.

Te ame trench and deector systemprotects thevehicle and pad structures rom the intense heat o launch.It is located in the ground-level ame trench that bisectsthe hardstand. A ame deector presents an inverted V-shape to the ames pouring into the trench through theopenings in the mobile launcher platorm.

Both sides o the upside-down V curve out near thebottom until they are almost horizontal. Flames ollow

these curves and deect horizontally down the ametrench, rather than bouncing back to envelop the vehicle.Te ame trench divides the hardstand lengthwise

rom ground level to the pad surace. It is 490 eet (149meters) long, 58 eet (18 meters) wide and 40 eet(12 meters) high. At launch, ames shoot out both endso the trench into the air. Te deector or the spaceshuttle is actually a two-in-one device, where one side othe inverted V receives the ames rom the orbiters mainengines, and the opposite side gets the ames rom thetwo solid rocket boosters. It is xed near the center o the

trench and extends completely across it.Te orbiter and booster deectors are built o steel

and covered with an ablative material about 5 inches(12.7 centimeters) thick that akes o to shed heat. Tesedeectors weigh more than 1 million pounds (453,600kilograms) each.

In addition to the xed deectors, two movable onesare located at the top o the trench or additional protec-tion rom the solid rocket booster ames.

Also located in the landing zone is a bunker, with anM-113 armored personnel carrier stationed nearby.

Te lightning mast extends above the xed servicestructure and provides a cone o protection over thevehicle and pad structures. A steel cable starts rom aground anchor 1,100 eet (335 meters) south o the xedservice structure, angles up and over the lightning mast,and then extends back down to a second ground anchorthe same distance to the north. Lightning strikes runto ground through this cable. Te mast unctions as an

electrical insulator, holding the cable away rom the tower.Te mast, with its accompanying support structure, listhe cable 100 eet (30.5 meters) above the steel o the xedservice structure.

Te emergency egress system provides an escaperoute or the astronauts in the orbiter and closeout crewon the xed service structure until the nal 30 seconds othe countdown. Seven slidewires extend rom the xedservice structure at the orbiter access arm level, down tothe ground. A at-bottom basket made o steel wire andheat-resistant ber, surrounded by netting, suspends romthe top o each o the seven wires. Each basket can holdup to three persons. Te basket slides down a 1,200-oot(366-meter) wire to an emergency shelter bunker locatedwest o the xed service structure. Te descent at about55 mph takes approximately 35 seconds; a braking systemusing a net and drag chain stops the slowing basket at thebottom.

Ater rollback o the rotating service structure, Space Shuttle

Atlantis can be seen atop the mobile launcher platorm on

Launch Pad 39A. Below the platorm is the fame trench, part

o the fame defector system that insulates pad structures

rom the intense heat o launch.



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A sound suppression water system has been in-stalled on the pads to protect the orbiter and its payloadsrom damage by acoustical energy and rocket exhaust

reected rom the ame trench and mobile launcher plat-orm during launch. Te shuttle orbiter, with its payloadsin the cargo hold, is much closer to the surace o the mo-bile launcher platorm than the Apollo spacecra was atthe top o a Saturn V or Saturn 1B vehicle.

Tesound suppression systemincludes an elevatedwater tank with a capacity o 300,000 gallons (1,135,620liters). Te tank is 290 eet (88 meters) high and is locatedadjacent to each pad.

Te water releases just prior to the ignition o the

shuttle engines, and ows th rough 7-oot-(2.1-meter-)diameter pipes or about 20 seconds. Water pours rom 16nozzles atop the ame deectors and rom outlets in themain engines exhaust hole in the mobile launcher plat-orm, starting at minus 6.6 seconds.

By the time the solid rocket boosters ignite, atorrent o water will be owing onto the mobile launcherplatorm rom six large quench nozzles, or rainbirds,mounted on its surace.

Te rainbirds are 12 eet (3.7 meters) high. Te two inthe center are 42 inches (107 centimeters) in diameter; theother our have a 30-inch (76-centimeter) diameter.

Te peak rate o ow rom all sources is 900,000 gal-lons (3,406,860 l iters) o water per minute at 9 secondsaer lio.

Acoustical levels reach their peak when the spaceshuttle is about 300 eet (91 meters) above the MLP, andcease to be a problem at an altitude o about 1,000 eet(305 meters).

Solid Rocket Booster Overpressure SuppressionSystem: Tis is part o the sound suppression watersystem. It alleviates the eect o a reected pressure

pulse that occurs at booster ignition. Without thesuppression system, this pressure would exert signi-cant orces on the wings and control suraces o theorbiter.

Tere are two primary components to this acousticenergy suppression system. A water spray systemprovides a cushion o water which is directed into theame hole directly beneath each booster. A series o

STS-106 Mission Specialists Richard A. Mastracchio (let) and Edward T. Lu take their seats in a slidewire basket, part o emergency

egress training at the launch pad.



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water bags stretched across the ame holes, providinga water mass to dampen the reected pressure pulse,supplements this eort.

Used together, this water barrier blocks the path othe reected pressure wave rom the boosters, greatlydecreasing its intensity.

In the event o an aborted mission, a post-shutdown

engine deluge system wi ll cool the a end o the orbiter.It also controls the burning o residual hydrogen gasaer the shuttles main engines have been shut downwith the vehicle on the pad. Tere are 22 nozzles aroundthe exhaust hole or the main engines within the mobilelauncher platorm. Fed by a 6-inch-diameter (15-centimeter-) supply line, water ows at a rate o up to 2,500gallons (9,463.5 liters) per minute.

Main Engine Hydrogen Burnof System: Hydro-gen vapors that occur during the main engine start se-quence expel into the engine nozzles just beore ignition.

Tis action results in a hydrogen-rich atmosphere in theengine bells. o prevent damage to the engines, six hy-drogen burno pre-igniters have been installed in the tailservice mast. Just beore main engine ignition, the

pre-igniters activate. Tey then ignite any ree hydrogenin the area below the engine bells. Tis avoids rough com-bustion at main engine start.

Te Propellant Storage Facilities are located at bothpads. A 900,000-gallon (3,406,860-liter) tank at each padstores the liquid oxygen, which is used as an oxidizer bythe orbiters main engines. Tese ball-shaped vessels areactually huge vacuum bottles. Tey maintain the super-

cold liquid oxygen at temperatures o minus 297 degreesF (minus 183 degrees C). wo pumps that supply 1,200gallons (4,540 liters) o oxidizer per minute each transerthe liquid oxygen rom the storage tank to the orbitersexternal tank.

Similar 850,000-gallon (3,217,590-liter) vacuumbottles at the northeast corner o the pads store the liquidhydrogen or the orbiters main engines. Pumps are not re-quired to move the liquid hydrogen rom the storage tankto the orbiters external tank during ueling operations.

First, a small amount o liquid hydrogen vaporizes.Tis action creates a gas pressure in the top o the tankthat moves the extremely light uel through the transerlines.

The 290-oot water tank at right o the launch pad holds 300,000 gallons o water that fow through outlets and fame defectors in the mobile

launcher platorm just beore launch to act as sound suppression. The confuence o the water and intense heat and fames rom the three

main engines and solid rocket boosters creates the billowing steam seen (fowing let rom the main engines and right rom the boosters)

during this launch o Space Shuttle Atlantis April 8, 2002, on mission STS-110.



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Ten vacuum-jacketed transer lines carry thesupercold propellants to t he mobile launcher platorm,where they eed through the orbiter into the external tankthrough the tail service masts.

Hypergolic propellants used by the orbiters orbitalmaneuvering engines and attitude control thrusters arealso stored at the pad in well-separated areas. A acilitylocated on the southeast corner o each pad holds the uel,monomethyl hydrazine. A acility on the southwestcorner stores the oxidizer, nitrogen tetroxide.

Tese propellants eed by transer lines to the xed

service structure and continue to the rotating servicestructures hypergolic umbilical system, with its threepairs o umbilicals attached to the orbiter.

Pad Terminal Connection Room

Elements located in the Pad erminal Connection

Room provide the vital links between the launch process-ing system in the Launch Control Center, the groundsupport equipment and shuttle ight hardware at the pad.Tis room lies below the pads elevated hardstand.

A large, round tank that is actually a huge vacuum bottle stores the supercold liquid hydrogen at the launch pad. A similar round

vessel holds the liquid oxygen. The liquid propellants fow to the orbiters main engines.



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At the launch pad, each side o the orbiters engine nozzles is connected to a tail service mast. The mast provides propellant-loading

umbilicals and establishes connections to ground support equipment.



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countdown nasa space shuttles and facilities

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