Category Apollo Saturn V News Reference

FIRST STAGE DESCRIPTION

The Saturn V first stage (S-IC) is a vertical group­ing of five cylindrical major components and a cluster of five F-l rocket engines. Upward from the engines are the thrust structure, fuel tank, inter­tank structure, LOX tank, and forward skirt. The total stage measures 138 feet in height and 33 feet in diameter without its fins. It weighs 6,100,000 pounds at liftoff and delivers 7.5 million pounds of thrust.

FIRST STAGE FABRICATION AND ASSEMBLY

Design, assembly, and test of the first stage booster are the prime tasks being performed by The Boeing Company at the Marshall Space Flight Center, Huntsville, Ala., the Michoud Assembly Facility, New Orleans, La., and the Mississippi Test Facility in southwestern Mississippi. Launch operations support is provided by the Boeing Atlantic Test

Center, Kennedy Space Center, Fla. Contractor suppliers lend support for much of the first stage fabrication. Several ground test stages were com­pleted before manufacture of a series of flight stages was begun. Huntsville and Michoud installations shared responsibility for assembly of four ground test stages and the first two flight stages. All other flight stages are being assembled at Michoud.

Assembled First Stage

Thrust Structure

The thrust structure is the heaviest of first stage components, weighing 24 tons. It is 33 feet in diam-

Base Assembly—Workmen cover the thrust structure shell with aluminum skin.

SATURN V NEWS REFERENCE

eter and about 20 feet tall with these major com­ponents: the lower thrust ring assembly, the center engine support assembly, four holddown posts, en­gine thrust posts, an upper thrust ring assembly, intermediate rings, and skin panel assemblies.

The upper ring provides stability for the corrugated skins around the structure. Four F-l engines are mounted circumferentially upon the thrust posts and the fifth upon the center engine support assem­bly. The center engine remains rigid while the others gimbal or swivel, allowing the stage to be guided.

A base heat shield protects internal parts from en­gine heat, and four holddown posts restrain the vehicle while the engines build up power for liftoff.

The thrust structure supports the entire vehicle weight and distributes the forces of the engines.

Thrust Structure—The 24-ton base of the booster is being taken to the Vertical Assembly Building for mating with other first stage components.

Fuel Tank

The fuel tank holds 203,000 gallons of kerosene and encloses a system of five LOX tunnels.

The tank, weighing more than 12 tons dry, is cap­able of releasing 1,350 gallons of kerosene per sec­ond to the engines through 10 fuel-suction lines. The LOX tunnels carry liquid oxygen from the LOX tank, through the fuel tank, and to the engines.

Bound by eight aluminum skin panels, the fusion – welded fuel tank assembly is 33 feet in diameter and 44 feet tall. Ends are enclosed by ellipsoidal bulkheads.

The bulkheads consist of eight pie-shaped gores mated with a polar cap to form a dome shape.

Connecting links between the skin rings and bulk­heads are circular bands known as the Y-rings. The Y-rings are used on both propellant tanks and link them to other segments of the booster at final

assembly.

Fuel Tank—Kerosene is fed to the engines at 1,300 gallons per second from this 203,000 gallon tank. Here the finished tank is being lowered onto its transporter.

Inside View—The fuel tank contains horizontal baffles, which are designed to prevent sloshing of fuel.

Fuel Tank Assembly – Workmen weld the base of the 27-inch – high Y-ring to the cylindrical segment of the fuel tank. This ring joins the tank sides to the dome and to the intertank structure.

The first stage film cameras provide photographic coverage of the LOX tank interior during launch, flight, and separation. The stage carries four film cameras. The two LOX-viewing cameras will pro­vide color motion pictures to show the following: behavior of the liquid oxygen, possible wave or slosh motions, and cascading or waterfall effects of the liquid from the internal tank structure. The capsules, which contain the cameras, are ejected automatically about 25 seconds after separation and are recovered after descent into the water. First stage flight versions of the camera consist of the LOX tank-viewing configuration plus two direct-viewing stage separation capsules. The in­stallation is in the forward skirt area. The tank­viewing optical lenses and the two strobe flash light assemblies are mounted in the LOX tank manhole covers. Connecting the remotely located camera capsules and the flash head are the optical assemblies, consisting of coupling lens attached to the ejection tube, a 9-foot length of fiber optics, and the objec­tive lens mounted in the flash-head assembly. The equipment required to complete the system, such as batteries, power supplies, timer, and synchroniz­ing circuitry, is contained in the environmentally controlled equipment racks or boxes mounted around the interior of the forward skirt structure. The combined timer and synchronizing unit serves

two functions. The digital pulse timer supplies real time correlation pulses which are printed on one edge of the film. The timer also supplies event marker pulses to the opposite edge of the film to record selected significant events such as liftoff, engine shutdown, and stage separation. The syn­chronizing unit times the intermittent illumination provided by the strobe lamps to coincide with the open portion of the rotating shutter as it passes the motion picture film gate. The capsule assembly consists of the heavy nose section and quartz win­dow, which protect the capsule during re-entry heating and impact on the water. The body of the capsule, including the camera, is sealed and water­tight. A paraloon and drag skirt aid its descent and flotation. A radio beacon and flashing light are mounted on the capsule to aid in recovery.

TELEVISION SYSTEM
stage separation. The system utilizes two split fiber optics viewing systems and two cameras. Ex­tremes in radiant heat, acoustics, and vibration prohibit the installation of the cameras in the en­gine area; therefore, fiber optics bundles are used to transmit the images to the cameras located in the thrust structure. Quartz windows are used to pro­tect the lens. Both nitrogen purging and a wiping action are used to prevent soot buildup on the pro­tective window.

Image enhancement improves the fiber-optical sys­tems by reducing the effects of voids between fibers and broken fibers. An optically flat disc with paral­lel surfaces rotates behind each objective lens.

The drive motor rotates in synchronism with the master drive motor. A DC to AC inverter energizes the synchronous drive motors. A camera control unit houses amplifiers, fly back, sweep, and other circuits required for the video system. Each vidicon output (30 frames/second) is amplified and sampled every other frame (15 frames/second) by the video register. A 2.5 watt FM transmitter feeds the 7- element yagi antenna array covered by a radome.

SECOND STAGE DESCRIPTION

The second stage of the Saturn V is the most power­ful hydrogen-fueled launch vehicle under produc­tion. Manufactured and assembled by North Amer­ican Aviation’s Space Division, it employs the cryogenic (ultra-low temperature) propellants of liquid hydrogen and liquid oxygen, which must be contained at temperatures of -423 and -297 degrees Fahrenheit, respectively.

For the lunar mission, the second stage takes over from the Saturn V’s first stage at an altitude of approximately 200,000 feet (38 miles) and boosts its payload of the third stage and Apollo space­craft to approximately 606,000 feet (114.5 miles). When its five J-2 engines ignite, the stage is pushing more than one million pounds, a load greater than that of any U. S. booster prior to the Saturn pro­gram. Speed of the stage ranges from 6,000 miles per hour to 15,300 miles per hour.

The beginning of second stage boost is a two-step process. Wien all the F-l engines of the first stage have cut off, the first stage separates. Eight ullage rocket motors located around the bottom of the second stage then fire for approximately 4 seconds to give positive acceleration to the stage prior to ignition of the five J-2 engines. About 30 seconds after the first stage separation, the part of the second stage structure on which the ullage rockets

Mating—A completed second stage is mated to a first stage at Kennedy Space Center, Fla. This particular stage was used for facilities checkout.

are located (the aft interstage) is separated by firing explosive charges. This second separation is a precise maneuver: the 18-foot-high interstage must slip past the engines without touching them. With the stage traveling at great speed, the inter­stage must clear the engines by only a little more than 3 feet.

The second stage burns for about 6 minutes, push­ing its payload into space. At the end of boost, all J-2 engines cut off at once, the stages separate, and the J-2 engine on the third stage begins firing to take it and the Apollo spacecraft into a parking earth orbit. The 81-foot 7-inch second stage is basically a container for its 942,000 pounds of pro­pellant with engines attached at the bottom. Pro­pellants represent more than 90 per cent of the stage’s total weight. Despite this great weight of propellant and the stresses the stage must take during launch and boost, the stage is primarily without an internal framework. It is constructed mostly of lightweight aluminum alloys ribbed in such a fashion that it is rigid enough to withstand the pressures to which it is subjected. Special lightweight insulation had to be developed to kc p its cryogenic propellants from warming and thus turning to gas and becoming totally useless as propellant. The insulation that helps maintain a difference of about 500 degrees between outside (70 to 80-degree normal Florida temperature) and inside (-423° F of liquid hydrogen) is only about 1-1/2 inches thick around the hydrogen tank.

A unique feature of the second stage is its common bulkhead, a single structure which is both the top of the liquid oxygen tank and the bottom of the liquid hydrogen tank. This bulkhead was a critical item in the development of the stage. The relatively thin bulkhead, consisting of two aluminum facing sheets separated by a phenolic honeycomb core insulation, must maintain a temperature difference of 126 degrees between the two sides. The insulation which accomplishes this varies from one-tenth of an inch thickness at the girth to 4-3/4 inches thickness at the apex of the bulkhead. Development of the com­mon bulkhead resulted in a weight saving of appox – imately 4 tons and more than 10 feet in stage length.

The flight control system provides stage thrust vector steering and attitude control. Steering is achieved by gimbaling the J-2 engine during pow-

SATURN V NEWS

ered flight. Hydraulic actuator assemblies provide J-2 engine deflection rates proportional to steering signal corrections supplied by the IU.

Stage roll attitude during powered flight is con­trolled by firing the APS attitude control engines.

DIAMETER: 260 in.

HEIGHT: 36 in.

WEIGHT: 4,500 lb. (approx.)

MAJOR SYSTEMS

ENVIRONMENTAL CONTROL SYSTEM: Provides cooling for electronic modules and

components within the IU and forward compartments of third stage

GUIDANCE AND CONTROL SYSTEM: Determines course of Saturn V through space

and adapts that course to fulfill mission requirements

INSTRUMENTATION SYSTEM: Measures vehicle conditions and reactions during

mission and transmits this information to ground for subsequent analysis,

as well as providing for ground station-to-vehicle communication

ELECTRICAL SYSTEM: Provides basic operating power for all electronic and

electrical equipment in the IU; also monitors vehicle performance and

may initiate automatic mission abort if an emergency arises

STRUCTURAL SYSTEM: Serves as a load bearing part

of the launch vehicle, supporting both the components

within the IU and the spacecraft; composed of three

120-degree segments of thin-wall aluminum alloy face

sheets bonded over a core of aluminum honeycomb

about an inch thick

SATURN V NEWS

num honeycomb. An aluminum alloy channel ring, bonded to the top and bottom edge of each segment, provides mating surfaces between the IU, the third stage, and the payload adapter. Mounted, inner skin brackets provide attachment points for the en­vironmental control system’s cold plates or for cold plate installation.

Segments are aligned and joined by splice plates bolted both inside and outside the joints. A spring – loaded umbilical door provides access to electrical connections between IU equipment and ground test areas. A larger access door, bolted in place, permits personnel to enter the IU after vehicle mating.

Assembly of an IU begins when the three curved structural segments, three feet high by 14 feet long, arrive at IBM’s Huntsville, Ala., facility. Each segment weighs only 140 pounds.

REFERENCE

structure. Components are mounted on the cold plates and ECS system pumps, storage tanks (called accumulators), heat exchangers, and plumbing are installed. Two nitrogen supply systems are installed: one for gas bearings of the inertial platform and the other for pressurization of the ECS. Finally, ducts, tubing, and electrical cables complete the assembly and the IU now weighing in excess of 4,000 pounds is ready for a long series of tests.

The mobile launcher is a movable launch platform with an integral umbilical tower. The launcher base

Arrival to Launch Pad—The facilities vehicle arrives at Launch Complex 39A.

is a two-story steel structure covering more than half an acre. The 380-foot tower, which supports the electrical servicing and fluid lines for the ve­hicle, is a steel structure mounted on the base. The base and tower weigh 10.5 million pounds and stand 445 feet above ground level.

Among major considerations in design of the mobile launcher were crew safety and escape provisions

and protection of the platform and its equipment from blast and sonic damage.

Personnel may be evacuated from upper work levels of the umbilical tower by a high speed elevator, descending at 600 feet per minute. After leaving the elevator, they can drop through a flexible metal chute into a blast and heatproof room inside the base of the pad hardstand.

The mobile launcher provides physical support and is a major facility for checkout of the space vehicle from assembly at the VAB until liftoff at the launch

site.

The top level of the launcher base houses digital acquisition units, computer systems, controls for actuation of service arms, communications equip­ment, water deluge panels, and other control units. Included in the lower level are hydraulic charging units, environmental control systems, electrical measuring equipment, and a terminal room for in­strumentation and communications interface. Mounted on the top deck of the base are four vehicle holddown and support arms and three tail service masts.

The umbilical tower is an open steel structure pro­viding support for nine umbilical service arms, 18 work and access platforms, and, for propellant, pneumatic, electrical, water, communications, and other service lines required to sustain the vehicle. A 250-ton capacity hammerhead crane is mounted atop the umbilical tower.

The launcher restrains the vehicle for approximately 5 seconds after ignition to allow thrust buildup and verification of full thrust from all engines. The design “up-load” during the holddown period is 3 million pounds. If one or more of the engines fail to develop full thrust, the vehicle is not released, and all engines automatically are shut down.

Night Shot—A 365-foot-tall Saturn V facilities vehicle Is shown in place at Launch Pad 39A.

SATURN V NEWS REFERENCE

The 331,000-gallon liquid oxygen tank is the largest component of the first stage booster, standing more than 64 feet in height. Its content is 297 degrees below zero Fahrenheit and provides the oxidizer to support combustion of the kerosene. Mixing of the two propellants is in a proportion to ensure complete combustion. Each second during flight, the engines consume more than 2,000 gallons of liquid oxygen.

LOX Tank… The completed 331,000-gallon LOX tank is being

carried to the hydrostatic testing facility where it will be tested for leaks.

The LOX tank’s construction is similar to that of the fuel tank with the LOX tunnels beginning at the tank base, running through the intertank and fuel tank and to the engines. Dry weight of the LOX tank exceeds 19 tons.

Intertank

The intertank is not a tank in itself but serves as a 6-1/2-ton link between fuel and LOX tanks. Its composition is 18 corrugated skin panels supported by five frame ring assemblies.

The lower bulkhead of the LOX tank dips into the intertank while the upper bulkhead of the fuel tank extends upward into the intertank. Around the edges of the intertank are attached 216 fittings, which fasten the tank together with the Y-rings of the fuel and LOX tanks. The intertank structure also contains a personnel access door.

Umbilical Openings

An umbilical opening in the intertank provides for electrical and instrumentation requirements, emergency LOX drain, line pressurization, elec­trical conduit, and provisions for venting internal pressure. The thrust structure contains three of four other umbilical openings on the booster. The fourth is located in the forward skirt. The thrust structure umbilicals carry the fuel line, liquid oxygen drain, ground supply fluid lines, and all control functions essential in case of a vehicle abort.

В 2835 34

B-6733-3

Fin and Fairing Assembly–Fairings are fitted over each of the outboard engines to smooth the air flow. Fins are attached to the fairings. B-9580-8

Forward Skirt–The structural link between the LOX tank and the engine shroud of the second stage is shown being lowered for dimensional inspection. FIRST STAGE FLIGHT Posted by admin in Apollo Saturn V News Reference on November 3, 2015 The first stage is loaded with RP-1 fuel and LOX at approximately 12 and 4 hours respectively, be­fore launch. With all systems in a ready condition, the stage is ignited by sending a start signal to the five F-l rocket engines. The engine main LOX valves open first allowing LOX to begin to enter the main thrust chamber. Next the engines’ gas generators and turbopumps are started. Each en­gine’s turbopump assembly will develop approx­imately 60,000 horsepower. Combustion is initiated by injecting a hypergolic solution into the engine’s main thrust chamber to react with the LOX already present. The main fuel valves then open, and fuel enters the combustion chamber to sustain the re­action previously initiated by the LOX and hyper­golic solution. Engine thrust then rapidly builds up to full level. The five engines are started in a 1-2-2 sequence, the center engine first and opposing out­board pairs at 300-millisecond stagger times. The stage is held down while the engines build up full thrust. After full thrust is reached and all engines and stage systems are functioning properly, the stage is released. This is accomplished by a “soft release” mechanism. First, the restraining hold­down arms are released. Immediately thereafter the vehicle begins to ascend but with a restraining force caused by tapered metal pins being pulled through holes. This “soft release” lasts for about 500 milliseconds. SATURN V NEWS REFERENCE The vehicle rises vertically to an altitude of approx­imately 430 feet to clear the launch umbilical tower and then begins a pitch and roll maneuver to attain the correct flight azimuth. As the vehicle continues its flight, its path is controlled by gimbaling the outboard F-l engines consistent with a prepro­grammed flight path and commanded by the instru­ment unit. At approximately 09 seconds into the flight, the vehicle experiences a condition of maximum dy­namic pressure. At this time, the restraining drag force is approximately equal to 400,000 pounds. At 135.5 seconds into the flight most of the LOX and fuel will be consumed, and a signal is sent from the instrument unit to shut down the center engine. The outboard engines continue to burn until either LOX or fuel depletion is sensed. LOX depletion is signaled w’hen a “dry” indication is received from at least two of the four LOX cutoff sensors; one sensor is located near the top of each outboard LOX suction duct. Fuel depletion is signaled by a “dry” indication from a redundant fuel cutoff sensor bolted directly to the fuel tank lower bulkhead. The LOX depletion cutoff is the main cutoff system with fuel cutoff as the backup. Six hundred milliseconds after the outboard engines receive a cutoff signal, a signal is given to fire the first stage retrorockets. Eight retroroekets are pro­vided and each produces an average effective thrust of 88,600 pounds for 0.666 seconds. The first stage separates from the second stage at an altitude of about 205,000 feet. It then ascends to a peak altitude near 366,000 feet before beginning its descent. While falling, the stage assumes a semistable en­gines down position and impacts into the Atlantic Ocean at approximately 350 miles down range of Cape Kennedy. ^ SATURN V NEWS REFERENCE F-l ENGINE FACT SHEET LENGTH WIDTH THRUST (sea level) SPECIFIC IMPULSE (minimum) RATED RUN DURATION FLOWRATE: Oxidizer Fuel MIXTURE RATIO CHAMBER PRESSURE WEIGHT FLIGHT CONFIGURATION EXPANSION AREA RATIO COMBUSTION TEMPERATURE: Thrust Chamber Gas Generator MAXIMUM NOZZLE EXIT DIAMETER 19 ft. 12 (t. 4 in. 1.500,0 lb. 260 sec. 150 sec. 3,945 lb. sec. (24,811 gpm) 1,738 lb. sec. (15,471 gpm) 2,27:1 oxidizer to fuel 965 psia 18,500 lb. maximum 16:1 with nozzle extension 10:1 without nozzle extension 5,970°F 1,465°F 11 ft. 7 in, ^ SATURN V NEWS REFERENCE STRUCTURE Posted by admin in Apollo Saturn V News Reference on November 3, 2015 The second stage structure consists of an inter­stage, which links it with the first stage; a thrust structure and aft skirt assembly, which supports and houses the five J-2 engines; an ellipsoidal liquid oxygen tank; a bolting ring, which attaches the liquid oxygen tank to the second stage structure; six aluminum cylinder walls, which are welded 4-1   Stacking Stage—Aft skirt, thrust structure, and common bulk­head move on transfer table to new station for further buildup of stage. lower ring. Four support rings along with an outer skin stiffened with hat sections comprise the basic structure. In addition, eight thrust longerons (two to each panel) extend upward along the conical surface of the thrust structure. The lower circum­ferential ring rests directly over the line of thrust of each of the four outboard engines while the cen­ter engine support beam assembly is directly over the thrust line of the center engine. A rigid heat shield mounted around the five J-2 engine •• to a frame connecting to the thrust structure protects the base area of the stage against recirculation of hot engine exhaust gases and heat from the ex­haust. This heat shield is of lightweight construc­tion protected by low-density ablative (heat-resis­tant) material. Although assembled separately, the aft skirt and thrust structure when joined become a structural entity and together support the five engines and withstand and distribute the thrust and boost struc­tural loads. In ado, tion to engines and engine accessories, the interstage, aft skirt, and thrust structure house electrical and mechanical equipment such as signal conditioners and controllers, telemetry electronics, flight control electronics, service and connecting umbilicals, electrical power control units, power distribution panels and batteries, inverters, propel­lant management electronics, propellant plumb­ing, ordnance installations, and hydraulic pumps and accumulators. Equipment that is not required after second-plane separation is in the interstage which is separated 30 seconds after ignition. Equipment necessary for flight operations is located on the aft skirt, thrust structure, and forward skirt. HYDRAULIC SYSTEM Posted by admin in Apollo Saturn V News Reference on November 3, 2015 The hydraulic system performs engine positioning upon command from the IU. Major components are a J-2 engine-driven hydraulic pump, two hydraulic actuator assemblies, and an accumulator-reservoir assembly. J-2 Engine Hydraulic System Components The electrically driven auxiliary hydraulic pump is started before vehicle liftoff to pressurize the hy­draulic system. Electric power for the pump is provided by a ground source. At liftoff, the pump is switched to stage battery power. Pressurization of the hydraulic system restrains the J-2 engine in a null position with relation to the third stage eenter- REFERENCE line, preventing pendulum-like shifting from forces encountered during liftoff and boost. During power­ed flight, the J-2 engine may be gimbaled up to 7° in a square pattern by the hydraulic system upon command from the IU. Engine-Driven Hydraulic Pump The engine-driven hydraulic pump is a variable dis­placement type pump capable of delivering hy­draulic fluid under continuous system pressure and varying volume as required for operation of the hy­draulic actuator assemblies. The pump is driven directly from the engine oxidizer turbopump. A thermal isolator in the system controls hydraulic – fluid temperature to ensure proper operation. Auxiliary Hydraulic Pump The auxiliary hydraulic pump is an electrically driven variable displacement pump which supplies a constant minimum supply of hydraulic fluid to the hydraulic system at all times. The pump is also used to perform preflight engine gimbaling check­outs, hydraulically lock the engine in the null posi­tion during boost phase, maintain system hydraulic – fluid at operating temperatures during other than the powered phase, and augment the engine-driven hydraulic pump during powered flight. It also pro­vides an emergency backup supply of fluid to the system. Hydraulic Actuator Assemblies Two hydraulic actuator assemblies are attached directly to the J-2 engine and the thrust structure and receive IU command signals to gimba! the en­gine. The actuator assemblies are identical and interchangeable. Accumulator-Reservoir Assembly The accumulator-reservoir assembly is an integral unit mounted on the thrust structure. The reservoir section is the storage area for hydraulic fluid; the accumulator section supplies peak system fluid re­quirements and dampens high-pressure surges with­in the system. 1 2 3 … 10 Next » Tweet Copyright © 2025 Aviation – airports, aircraft, helicopters … - Everything about aviation. Aviation News from around the world. Commercial and General Aviation, airports, airplanes, helicopters and other aircraft.