If the Vehicle Assembly Building is the heart of Launch Complex 39, the Launch Control Center is its brain. The LCC is a four-story structure located on the southeast side of the VAB and connected to it by an enclosed bridge for utilities.
Office space and a utilities systems control room are located on the first floor. The control data subsystem occupies the core of the second floor. Four firing rooms occupy most of the third floor. The fourth floor is used for office areas.
KSC's automated launch processing system controls and performs much of the space shuttle vehicle checkout automatically while the vehicle components are being prepared for launch. It also conducts countdown and launch operations.
The LPS is divided into three major subsystems: the central data subsystem; the checkout, control and monitor subsystem; and the record and playback subsystem.
The central data subsystem consists of large-scale computers (built by Honeywell) that store test procedures, vehicle processing data, a master program library, historical data, pre- and posttest data analyses and other data. The information stored in these large-scale computers is immediately available to the smaller capacity computers of the checkout, control and monitor subsystem. The CDS is located on the second floor of the LCC.
The checkout, control and monitor subsystem consists of consoles, minicomputers and related equipment located in the LCC firing rooms and support areas. The subsystem is used to process and launch the space shuttle vehicle. Vehicle checkout, countdown and launch are conducted with the support of the information stored in the CDS.
Automatic checkout from the firing rooms is accomplished using computer programs to monitor and record the prelaunch performance of all electrical and mechanical systems. Command signals from the CCMS computer are sent to the various components and test circuits.
While a space shuttle vehicle component is functioning, a sensor measures its performance and sends data back to the LPS for comparison against the checkout limits stored in the system's computer memory. Predetermined measurements related to test requirements, launch commit criteria and performance specifications are stored in the CCMS computers.
When the checkout program is complete, a signal indicates whether or not its performance has been satisfactory. If unsatisfactory, the CCMS computers then provide data that support isolation of the fault. The process continues throughout vehicle checkout.
The primary function of the record and playback subsystem is to record unprocessed space shuttle instrumentation data during tests and launch countdowns. These recordings can then be played back for posttest analysis when firing room personnel are troubleshooting space shuttle or LPS problems. The subsystem consists of instrumentation tape recorders, telemetry demultiplexing equipment, direct-write recorders, and computers to provide data-reduction capabilities. The subsystem also provides certain functions in support of the CCMS and CDS portions of the LPS. These include the playback of data from downrange instrumentation tapes sent to KSC for data analysis by systems engineers.
Operations at the launch pad are controlled from the Launch Control Center after the space shuttle has been rolled out. Once the mobile launcher platform is in place on the pad support columns, the rotating service structure is extended around the shuttle and the shuttle vehicle can be powered up. (The space shuttle can be powered up if the RSS is not extended.)
The mobile launcher platform and the space shuttle are electrically and mechanically mated with the supporting pad facilities and ground support equipment, and all interfaces are verified in a series of launch pad validation checks.
In parallel with other pad activities, payload operations are performed in the RSS's payload changeout room. Spacecraft that are integrated vertically in the space shuttle vehicle arrive at the launch pad ahead of the space shuttle and are temporarily stored in the PCR. After the RSS is extended around the orbiter, the payload bay doors are opened, and the payload is installed. Payload-to-orbiter interface verifications are performed; and any required operations, such as spacecraft and upper stage battery charging, are conducted.
FLIGHT READINESS FIRING AND EXTERNAL TANK TANKING TESTS
Procedures have been developed for conducting test firings of the space shuttle orbiter's main engines on the pad to validate the entire main propulsion system of each new orbiter. The test firing lasts approximately 20 seconds. The orbiter is not manned during flight readiness firing operations.
The launch confidence test (formerly called the wet countdown demonstration test) validates tanking procedures and verifies ET hardware under simulated flight tanking conditions. Another test verifies that the ET insulation will not debond following the cryo tanking. No flight crew is on board the vehicle during these tests.
A terminal countdown demonstration test simulates the final hours of a launch countdown and serves as a practice exercise in which both the launch team and flight crew rehearse launch day time lines and procedures. The test culminates in a simulated ignition and automated shutdown of the orbiter's main engines. Following the simulated T-0, the flight crew is briefed on emergency egress procedures and use of the fixed service structure slidewire system.
This test supports an important function for the KSC launch team. During what is called the malfunction run, the test simulates real-time failures of vehicle and ground systems. The test also provides support crew astronauts with crew module training.
PRELAUNCH PROPELLANT LOAD
The prelaunch propellant load begins with setups and preparations to load hyper golic propellants in the orbiter's onboard OMS/RCS pods and forward RCS propellant tanks and helium in the pods and forward RCS storage tanks. During the operation, hydrazine servicing of the orbiter's auxiliary power units and solid rocket booster hydraulic power units is completed.
The pad is cleared to the perimeter gate during the hazardous operation of loading nitrogen tetroxide oxidizer and monomethyl hydrazine fuel in the orbiter's OMS/RCS pods and forward RCS and hydrazine in the APUs and SRB HPUs. Because the propellants are hypergolic, meaning they ignite on contact with one another, the oxidizer and fuel loading operations are conducted serially, not in parallel.
Another loading operation is the filling of fixed service structure Dewar tanks with cryogenic reactants. The tanks are loaded with liquid oxygen and liquid hydrogen, which subsequently are loaded into the orbiter's onboard power reactant storage and distribution tanks during the launch countdown.
The shuttle vehicle is powered down on the pad for final installation/hookup of pyrotechnic devices (ordnance). Space shuttle range safety ordnance connections are completed just before the launch countdown starts.
The extravehicular mobility units-the shuttle space suits-and other flight crew equipment are stowed on the pad.
Final vehicle and facility closeouts are performed during a precountdown preparation period as the shuttle and its supporting launch pad facilities are readied for the launch countdown.
The shuttle launch countdown has become relatively routine and standardized. The countdown time begins approximately 43 hours before the launch.
ET tanking preparations are begun in parallel with the activation of various vehicle systems. A built-in hold period, the duration of which depends on lift-off time, begins at the T minus 11 hours mark. The hold provides the launch team an opportunity to catch up on any preparations that may be running behind schedule and to troubleshoot any vehicle or ground support equipment problems that may constrain the count.
The final hours of the count include a final mission software update, completion of propellant system purges, propellant line chilling, loading of liquid hydrogen and liquid oxygen in the external tank, crew entry, terminal sequence and lift-off.
At T minus nine minutes, following a 10-minute built-in hold, the KSC-developed ground launch sequencer takes over. From this point on, all functions in the terminal count are under computer control.
Associated with space shuttle operations at the Kennedy Space Center is the retrieval and refurbishment of the two reusable solid rocket boosters.
Two specially designed and constructed retrieval vessels recover the boosters and their various components. The Liberty Star and the Freedom Star are 176 feet long, have a beam of 37 feet, have a depth of 15 feet and draw 9 feet of water. Both ships are used on shuttle missions.
Of molded steel hull construction, the recovery vessels have sophisticated electronic communications and navigation equipment, including a global positioning navigation system, search radars, collision-avoidance sonars with transponders, radars, loran C, VHF and single-side-band high-frequency radio systems, direction finders, fathometers and gyro compasses. Each vessel has a displacement of 1,052 tons.
At sea, propulsion is provided by twin diesel engines with a combined power output of 2,900 horsepower. Maneuvering is provided by a diesel-driven, 425-horsepower bow thruster.
The ships leave their Cape Canaveral Air Force Station berths at Hangar AF about 24 hours before launch and proceed to the predicted impact site. Traveling at a cruising speed of 10 to 12 knots, they reach the area in about 10 hours. In the hours before lift-off, the ships conduct visual and electronic sweeps of the predicted impact area to ensure it is clear.
Each ship recovers one SRB casing, three main parachutes, and a frustum-drogue combination.
Recovery begins with retrieval of the main parachutes. Each recovery vessel has four large deck reels 5.5 feet across. The reels can hold two parachutes each. The parachutes' winch lines are fed onto the spools, and the parachutes are wound around them like line on a fishing reel.
Retrieval of the frustum-drogue parachute begins in the same way. The drogue parachute is wound around one of the large reels until the 5,000-pound frustum is approximately 100 feet from the ship. The drogue parachute's shroud lines are then rolled in until the frustum can be hoisted out of the water by a 10-ton crane.
Recovery of the two spent solid rocket booster casings, the last phase of the recovery mission, is accomplished using a diver-operated plug. The diver descends to a depth of approximately 110 feet and inserts a diver-operated plug in the nozzle of each casing. A 2,000-foot-long air line is attached from the DOP to an air compressor on the retrieval vessel. Air is pumped at a pressure at 120 psi to dewater the booster and permit towing of the casing back to port.
Under optimum sea conditions, booster retrieval operations are completed about five hours and 30 minutes after the launch. The ships then proceed back to Cape Canaveral and up the Banana River to Hangar AF at the Cape Canaveral Air Force Station.
The Solid Rocket Booster Disassembly Facility is located in Hangar AF at the Cape Canaveral Air Force Station on the eastern shore of the Banana River. Access to the Atlantic Ocean, from which the boosters are retrieved by ship after jettison during the space shuttle launch phase, is provided by the locks at Port Canaveral. A tributary channel from the disassembly facility ties in with the main channel of the Banana River for access to the Kennedy Space Center.
Recovery vessels tow the expended boosters in the horizontal position into the disassembly facility's off-loading area, where they are properly centered in a hoisting slip. Mobile gantry cranes on the hoisting slip lift the booster onto a standard-gauge tracked dolly for safing and preliminary washing. The nose cone frustums and parachutes are off-loaded for processing at other facilities. After safing and washing, the solid rocket booster casings are moved into the disassembly facility for disassembly to the level of major elements, consisting of eight solid rocket booster segments, the two aft skirt assemblies and the two forward skirt assemblies. The segments then undergo final cleaning and stripping before they are shipped to the Refurbishment Processing Facility by truck. From there, the segments are shipped by rail to the prime contractor in Utah for final refurbishing and loading with propellant.
The Parachute Refurbishment Facility is located in the Kennedy Space Center industrial area south of the Operations and Checkout Building.
Parachute systems recovered concurrently with the SRB casings are delivered to the refurbishment facility on reels provided on the retrieval vessels for that purpose. The parachutes for the solid rocket boosters are washed, dried, refurbished, assembled and stored in this facility. New parachutes and hardware from manufacturers also are delivered to the Parachute Refurbishment Facility.
Parachutes arriving from the retrieval operations are untangled, hung systematically on an overhead monorail, and transported to in-line washers and driers that wash and dry them automatically. They are then sent to the refurbishing area, which is equipped with handling equipment for producing and installing risers and associated equipment. After final inspection and acceptance, the chutes are folded and placed in canisters for reuse.
Twenty work tables 8 feet long, 6 feet wide and 30 inches high were obtained from the Johnson Space Center. Eight of these tables have been strung together to provide a structure 64 feet long and 6 feet wide for SRB parachute processing. A number of the 12 remaining tables are used in the parachute facility's major repair area.
The concrete runway of the shuttle landing facility is located northwest of the Vehicle Assembly Building on a northwest/southeast alignment (330 degrees northwest/150 degrees southeast). The runway is 15,000 feet long and 300 feet wide with a 1,000-foot safety overrun at each end. A paved runway at Edwards Air Force Base in California matches the Kennedy Space Center runway in length and width and has an overrun of 5 miles that extends into a dry lake bed.
The shuttle landing facility runway is 16 inches thick in the center with the thickness diminishing to 15 inches on the sides. The runway is not perfectly flat but has a slope of 24 inches from centerline to edge. Underlying the concrete paving, completed in late 1975, is a 6-inch-thick base of soil cement.
The runway is grooved to prevent hydroplaning in wet weather. The slope of the runway from centerline to edge promotes rapid draining of any water from a heavy Florida rain to help combat hydroplaning.
Modifications have been made to the Kennedy Space Center runway. The full 300-foot width of 3,500-foot sections at both ends of the runway was ground to smooth the runway surface texture and remove cross grooves. The modified corduroy ridges are smaller than those they replaced and run the length of the runway rather than across its width. The existing landing zone light fixtures were also modified, and the markings of the entire runway and overruns were repainted. The primary purpose of the modifications is to enhance safety by reducing space shuttle orbiter tire wear during landing.
In general terms, the runway is roughly twice as long and twice as wide as average commercial runways, although a number of domestic and foreign airports have landing strips far exceeding average dimensions. The shuttle landing facility includes a 550- by 490-foot aircraft parking apron, or ramp, located near the southeastern end of the runway. The landing facility is linked with the Orbiter Processing Facility by a 2-mile tow-way.
On the northeast corner of the shuttle landing facility ramp area is the mate/demate device used to raise and lower the orbiter from its shuttle carrier aircraft during ferry operations. The device is an open-truss steel structure with the hoists and adapters required to mate the orbiter to and demate it from the shuttle carrier aircraft. The mating and demating operations are performed before and after each ferry flight. Movable platforms for access to certain orbiter components and equipment for jacking the orbiter are also provided.
The mate/demate device is intended to be used in the open air and is designed to withstand winds of up to 125 mph. Lightning protection is included. The MDD is 150 feet long, 93 feet wide and 105 feet high. A similar device is located at NASA's Dryden Flight Research Facility, and a third is located at Vandenberg Air Force Base.
Also located at the shuttle landing facility is a landing aid control building near the aircraft parking apron. The building supports control operations and houses the personnel who perform shuttle landing facility operations.
Landings may be made on the runway from the northwest to the southeast (Runway 15) or from the southeast to the northwest (Runway 33), and microwave scan beam landing system ground stations are duplicated to permit an approach from either direction.
Even with the sophisticated electronic approach and landing aids, visual aids have not been overlooked.
The runway is served by a high-intensity lighting system that is common at many commercial airports. It contains a variable intensity control with five intensity settings. Runway edge lights are white except for the last 2,000 feet at each end of the runway, which are marked by amber lights. The lights marking the limits of the runway length emit red light toward the runway and green light outward from the runway end, indicating the landing threshold to pilots.
The precision approach path indicator system is a visual reference for determining the orbiter's outer glide slope approach angle.
Both ends of the runway utilize identical approach lighting systems with sequenced flashing lights. The systems, known as ALSF-2, extend 3,000 feet beyond the runway ends and have five intensity settings. The sequenced flashers are used during periods of reduced visibility and appear to pilots as a ball of light traveling toward the runway along the center of the approach lights, recurring twice each second.
The runway edge lighting and approach light systems are controlled by the operations staff from the landing aid control building.
Portable, high-intensity xenon lights are available to illuminate the touchdown zone to support orbiter landings in darkness. These lights are used because the orbiter has no landing lights of its own.
The towing tractors at the Kennedy Space Center are similar to those that tow aircraft at commercial airports. At KSC, the tractor is used to tow orbiters, the shuttle carrier aircraft and other aircraft weighing 820,000 pounds or less between the shuttle landing facility, the Orbiter Processing Facility and the Vertical Assembly Building. It also tows the external tank transporter from the Vehicle Assembly Building turn basin dock area to the external tank checkout facility in High Bay 4 of the Vehicle Assembly Building.
The tractor is 16 feet long, 8 feet wide and 7.3 feet high. The basic weight is 65,000 pounds; its ballasted weight is 110,000 pounds. Its maximum speed is 20 mph and its towing speed is 5 mph. The towing tractor is powered by a 191-kilowatt (256-horse power) diesel engine. Its fully automatic transmission has six forward speeds and one reverse speed. A diesel-driven ground-power generator provides the orbiter (or other aircraft being towed) with 115-volt, 400-hertz, three-phase ac electrical power.
Information content from the NSTS Shuttle Reference Manual (1988)
Last Hypertexed Friday April 17 00:14:18 EDT 1998
Jim Dumoulin (email@example.com)
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