Part 3

[Illustration: 39. The exterior of eight-sided _Relay_ is composed of honeycomb aluminum panels studded with 8215 solar cells.]

The world’s first commercial communications satellite was called “Early Bird,” or INTELSAT 1. Built a decade ago by Hughes Aircraft Company for Communications Satellite Corporation (COMSAT), Early Bird could transmit simultaneously on 240 two-way channels for telephone, telegraph, or data transmission. Transatlantic telephone circuit capability increased by 50 percent once Early Bird went into orbit on April 6, 1965. Although the craft had a life expectancy of 18 months, it operated satisfactorily in full-time service for more than three and one-half years.

INTELSAT 2 introduced multipoint communications between earth stations in the Northern and Southern hemispheres. With almost twice the power of Early Bird, INTELSAT 2 proved particularly important as communications support for the Apollo missions to the Moon.

INTELSAT 2 established a global network of three satellites that was effective in linking two-thirds of the world’s people in one communications chain. The first of the series was launched on January 11, 1967. These spacecraft were designed and manufactured by the Hughes Aircraft Company for Intelsat, Inc., and had a design lifetime of three years.

INTELSAT 3 was a series of five communications satellites which provided global coverage for the first time. This INTELSAT had a capacity of 2400 voice, data, facsimile, and telegraph circuits, plus four television channels and had a design lifetime of five years.

The satellite featured a de-spun antenna which remained pointed at a

## particular area of the globe, while the body of the satellite spun

around it. It was the first commercial satellite capable of transmitting voice and television broadcasts simultaneously.

INTELSAT 3 satellites were manufactured by TRW Systems, Inc., for Intelsat, Inc.

_Echo 2_, _Courier 1-B_, and _Relay_ are from the National Aeronautics and Space Administration; _OSCAR 1_ is from Project Oscar, Inc.; INTELSAT 1, INTELSAT 2, and INTELSAT 3 are from the International Telecommunications Satellite Organization.

Lunar Module

[Illustration: 40. Apollo 15 Lunar Module, center, on the Moon. Astronaut Irwin on left and Lunar Roving Vehicle on right.]

The lunar module is one of twelve built for the Apollo moon-landing program. Although this one never flew because an earlier test flight was completely successful, two-stage lunar modules like this one have been used for each manned moon landing.

Lunar modules do not have to be streamlined for flights through the vacuum of space or to withstand reentry. The lunar module (LM) lifts off from Earth enclosed in a compartment of the Saturn 5 launch vehicle, below the command-service module that houses the astronauts. The command module pulls the LM from its storage area once the spacecraft are on their way to the Moon, and the two travel together until they arrive in lunar orbit.

When the crew is ready to land, two of the three astronauts enter the LM and undock it, leaving the third to pilot the command module. After touchdown on the Moon, the astronauts exit through the door above the ladder.

The silver and black ascent stage, containing the astronauts’ pressurized compartment and the clusters of rockets that control the spacecraft, fits on top of the shiny gold descent stage that actually touches down on the Moon. The descent stage contains a main, centrally located rocket engine. This segment of the craft remains on the Moon as the crew lifts off in the ascent stage to rejoin the command module.

After the crew transfers to the command module, the ascent stage is also left behind as the three crew members start their return journey.

The LM is displayed just as it would look during a moon-landing mission. The gold and black materials insulate the spacecraft’s inner structure from temperature extremes and protect it from micrometeoroids. Thin sheets of both materials are used in “blankets” to accomplish the necessary protection in a foreign environment.

The black material is heat-resistant nickel-steel alloy. Each sheet is only .002 millimeters (1/12,000 of an inch) thick. These absorb heat and radiate it back into the blackness of space.

The shiny gold material on the descent stage is aluminum that is thinly coated over plastic film. The thin sheets of plastic and aluminum are used in blankets of up to 25 layers for protection and insulation of the spacecraft.

Prime contractor for the lunar module was Grumman Aerospace Corporation.

The lunar module on exhibit is from the National Aeronautics and Space Administration.

Height 7 m. (22 ft., 11 in.), legs extended Diameter 9.4 m. (31 ft.) diagonally across landing gear Weight Earth launch 14,700 kg. (32,400 lb.) LM (dry) 3900 kg. (8600 lb.) Volume Pressurized 6.7 cu. m. (235 cu. ft.) Habitable 4.5 cu. m. (160 cu. ft.)

[Illustration: 41. Lunar Module Center Instrument Panel in the ascent stage.]

Lunar Orbiter

[Illustration: 42. Lunar Orbiter.]

Directional Antenna Velocity Control Rocket Engine Fuel Tank Nitrogen Gas Reaction Jets Oxidizer Tank Lenses Micrometeoroid Detectors Flight Programmer Photographic Subsystem Sun Sensor (located under equipment deck) Solar Panel Canopus Star Tracker Inertial Reference Unit Omni Directional Antenna

The Lunar Orbiter project was initiated in 1963 as part of the U.S. Apollo program to land men on the Moon during the decade of the nineteen sixties.

Lunar Orbiter’s primary mission was to take and transmit both wide-angle and closeup images of the Moon. Lunar Orbiters photographed many areas of scientific interest and provided general photographic coverage of much of the moon’s surface. These pictures were then used to select the best landing sites for the first manned lunar landings. Orbiters also showed that the moon’s gravitational field permitted stable orbits.

_Lunar Orbiter 1_ was launched atop an Atlas-Agena D rocket on August 10, 1966. The last in the project, _Lunar Orbiter 5_, was launched on August 1, 1967. All five missions were successful.

The first three missions were similar. After each launch, the Agena stage’s booster engine was fired to send the spacecraft on a 90-hour coasting trajectory to the Moon, about 386,160 kilometers (240,000 miles) distant.

As the spacecraft neared the Moon, its on-board engine was fired as a retrorocket to slow the _Orbiter_ and permit it to go into orbit around the Moon.

The closest approach to the Moon in each orbit was about 45 kilometers (28 miles), and the spacecraft swung out to about 1850 kilometers (1150 miles) from the Moon.

Photography was conducted while the _Orbiter_ was near the lunar surface. Lunar photography for the Apollo Program landing-site selection was completed by the first three Lunar Orbiters. Each was then intentionally crashed into the Moon to prevent it from interfering with later missions.

The last two Lunar Orbiters were used for scientific photography of the Moon. Both were placed into polar orbits so that they could photograph all of the sunlit areas of the Moon.

Each Lunar Orbiter carried a camera with both a telephoto and a wide-angle lens. The telephoto lens was capable of resolving objects on the lunar surface as small as 91.4 centimeters (three feet) in diameter. The wide-angle lens could resolve objects as small as 7.6 meters (25 feet) in diameter. The photographic images were converted to electrical signals for transmission to Earth.

The Lunar Orbiter project was a complete success. All spacecraft operated properly, photographing a total of more than 36-million square kilometers (14-million square miles) of the moon’s surface.

Prime contractor for the Lunar Orbiter program was the Boeing Company. Principal subcontractors were Eastman Kodak Company and RCA.

The Lunar Orbiter in the National Air and Space Museum’s collection was used for thermal testing of spacecraft systems.

_Lunar Orbiter_ is from the National Aeronautics and Space Administration.

Maximum span Antenna booms 5.6 m. (18 ft., 6 in.) Solar panels 3.7 m. (12 ft., 2 in.) Height 1.68 m. (5 ft., 6 in.) without panels Weight 385.6 kg. (850 lb.) Power Electrical; four solar panels with a total area of just over 4.8 sq. m. (58 sq. ft.) providing 375 w. to nickel-cadmium batteries Velocity control A 45.4 kg (100 lb.) thrust engine burning a system hydrazine mixture and nitrogen-tetroxide oxidizer

Surveyor

[Illustration: 43. Surveyor.]

High-gain Antenna Omnidirectional Antenna A Thermally Controlled Compartment A Radar Altitude - Doppler Velocity Sensor Vernier Propellant Tanks Footpad 2 Crushable Block Attitude Control Gas Tank (Nitrogen) Solar Panel TV Camera Thermally Controlled Compartment B Alpha Scattering Instrument Electronics Canopus Star Sensor Omnidirectional Antenna B Footpad 3 Vernier Engine 3 Vernier Propellant Pressurizing Gas Tank (Helium) Alpha Scattering Instrument

[Illustration: 44. _Apollo 12_ crewman examines _Surveyor 3_, which soft-landed on the Moon on April 19, 1967. The _Apollo 12_ (1969) Lunar Module is in the background.]

The Surveyor Project, begun in 1960, consisted of seven unmanned spacecraft which were launched between May 30, 1966, and January 6, 1968. The craft were used to develop lunar soft-landing techniques, to survey potential Apollo landing sites, and to improve scientific understanding of the Moon.

Five of the seven Surveyor spacecraft successfully landed on the Moon and performed their tasks well. They responded to 600,545 commands from Earth and returned 87,632 television images of their lunar surroundings. (_Surveyors 2_ and _4_ crashed into the Moon and were destroyed.)

Besides returning TV images, _Surveyors 3_, _5_, _6_, and _7_ carried a soil-sampling claw which could dig a trench, and test soil hardness and other characteristics. The soil-sampler tests showed that the lunar surface would bear the weight of an Apollo Lunar Module.

_Surveyors 5_, _6_, and _7_ carried instruments capable of making simple chemical analyses of the lunar soil near the spacecraft. This information told scientists that most lunar soil near the Surveyors was basalt, a common rock on Earth as well.

The Surveyor spacecraft on exhibit, designated _S-10_, was used in ground-based tests of on-board equipment, and was not used on a mission. _S-10_ is exhibited as it would have appeared just before landing on the Moon.

Prime contractor for the Surveyor spacecraft was the Hughes Aircraft Company. The project was managed by the National Aeronautics and Space Administration, Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California.

The spacecraft on exhibit is from the National Aeronautics and Space Administration.

Height 3 m. (10 ft.) Distance across 3.5 m. (11 ft., 6 in.) footpads Weight 1000 kg. (2204 lb.) at launch; 292 kg. (644 lb.) as exhibited Electrical power One .83 sq. m. (9 sq. ft.) solar panel providing 89 w. to a silver-zinc battery Landing vernier Three throttleable liquid-propellant rockets rocket system each providing from 14.6 to 47.2 kg. thrust (30 to 104 lb. thrust). Fuel—Monomethylhydrazine monohydrate; oxidizer 90% nitrogen tetroxide and 10% nitric oxide.

Goddard Rockets: May 1926 and “Hoopskirt,” 1928

The American pioneer of astronautics, Robert H. Goddard (1882-1945) not only outlined the physical principles that would govern space flight, but he also constructed and tested many rocket engines, airframes, control devices, and guidance mechanisms between 1926 and 1942.

Goddard held a doctorate in physics, and was a professor at Clark University, Worcester, Massachusetts. The Smithsonian Institution began funding Goddard’s experiments as early as 1917 and published his first major work, _A Method of Reaching Extreme Altitudes_, in 1919.

Goddard was not only a trained scientist, but a talented and ingenious engineer as well. On March 16, 1926, he launched the world’s first liquid-propellant rocket. By 1930, he had established a rocket test facility at Mescalero Ranch, near Roswell, New Mexico. Here, he conducted research, funded by the Daniel and Florence Guggenheim Foundation, on rocket power plants, pumps and fuel systems, control mechanisms, and other vital elements of the modern rocket.

The Rocket of May 4, 1926

This vehicle is the oldest surviving liquid-propellant rocket in the world. Built of parts employed in the first liquid-propellant rocket launched on March 16, 1926, the engine was moved from the nose of the vehicle to the rear for the May 4 trial. Other changes were introduced to reduce the weight of the rocket to 2.5 kilograms (5.5 pounds). The motor burned gasoline and liquid oxygen.

The alcohol burner under the liquid oxygen tank was inadvertently not ignited, causing the May 4 attempted launch to fail. A second test on May 5 also proved unsuccessful. However, the rocket engine was fired on both occasions.

The May 4 rocket is from Mrs. Robert H. Goddard and the Daniel and Florence Guggenheim Foundation.

May 1926 rocket

Length 1.95 m. (6 ft., 4 in.) Weight 2.5 kg. (5.5 lb.) Fuel Gasoline Oxidizer Liquid oxygen

The “Hoopskirt” Rocket

[Illustration: 45. Dr. Goddard and the “Hoopskirt.” Propellant tanks are on legs of frame.]

[Illustration: 46. The upper section of the “Hoopskirt” rocket.]

Developed by Dr. Goddard during the late summer and early fall of 1928, the “Hoopskirt” rocket featured a small rocket engine mounted in the nose and a system of tanks and alcohol burners—to maintain fuel pressure—mounted on two legs. On December 26, 1928, the rocket flew 62.33 meters (204.5 feet) in 3.2 seconds—its most successful flight. Like all Goddard rockets, the “Hoopskirt” burned gasoline and liquid oxygen.

The “Hoopskirt” rocket is from Mrs. Robert H. Goddard.

“Hoopskirt”

Height 4.5 m. (14 ft., 8 in.) Weight 12.93 kg. (28.5 lb.) Fuel Gasoline Oxidizer Liquid oxygen

19th-Century Rockets: Congreve and Hale

[Illustration: 47. _The Bombardment of Algiers_, 1816. Congreve rockets in use.]

The rebirth of European interest in military rocketry can be traced to the English conquest of India during the late 18th century. William Congreve, an artillery expert, was intrigued by the tactical success of the Indian war rockets. He began a research program in 1804 that led to the development of a metal-cased, stick-guided artillery rocket that could be fired in barrages against enemy troops. The rocket carried incendiary or explosive warheads.

The 14.5-kilogram (32-pound) Congreve war rocket models on display show the early side-mounting of the stabilizing guide stick and the later (1815) design in which the guide stick was center-mounted to give greater accuracy. Congreve rockets played an important role during the Napoleonic Wars and the War of 1812.

The experimental 45.4-kilogram (100-pound) Congreve incendiary rocket was developed as a siege weapon for use against fortresses or entrenched enemy positions, although it is not known to have been used in combat. The 6.7-meter (22-foot) guide stick screwed together and fitted to the side of the projectile before firing. Like the smaller Congreve rockets, it could be launched from a frame or earthen embankment.

William Hale was an English engineer and ordnance expert who made cumbersome guide sticks obsolete with the introduction of spin stabilization to rocketry. Hale’s first design of a stickless, or rotary, rocket was patented in 1844. Although the 5.4-kilogram (12-pound) rocket was used during the Mexican War (1846-1847) and the Civil War, Hale subsequently refined it because the rocket had a tendency to oscillate in the air following exhaustion of the propellant.

Hale’s intermediate pattern rocket of 1862—on display—was never produced, giving way in 1865 to a rocket weighing 11 kilograms (24 pounds) with a maximum range of 2012 meters (2200 yards) when fired from a 4.6-meter (15-foot) elevation. The propellant burned for 5 to 10 seconds, producing an estimated maximum thrust of 136 kilograms (300 pounds).

The American version of the Hale rocket has two sets of gas nozzles. The major aperture on the base of the case allowed the propellant gases to escape. The smaller holes above the rocket’s midpoint are angled; the exhaust gases spin the projectile, stabilizing it during flight. Hale rocket designs were employed by both sides during the Civil War.

[Illustration: 48. Hale rocket with canted nozzles for spin-stabilization.]

The Congreve 14.5-kilogram (32-pound) war rocket model was copied from the original at the Royal Artillery Institution; the experimental Congreve incendiary rocket on display is a gift of that Institution. Hale’s 1844 design rocket, his 1862 experimental rocket, and the 1865 rocket are on loan from the Science Museum, London. The American Hale rocket is on loan from F. C. Durant III.

American Rocket Society: Engines and Parts

[Illustration: 49. Static test of liquid-fuel rocket engine on American Rocket Society Test Stand No. 2.]

[Illustration: 50. Two early types of liquid-fuel, rocket motors. Left, the original ARS motor; right, a four-nozzle motor for ARS No. 4 rocket.]

Thrust stud for fastening to rocket Blast chamber Fuel feed Oxygen feed Nozzle Water jacket Nozzles Thrust and fuel column attached to rocket Fuel feed Oxygen feed

The American Rocket Society (ARS) was the first organization in the United States dedicated to rocket research. The society was founded in New York City in March 1930 by G. E. Pendray and David Laser. The first successful ARS rocket was launched on May 13, 1933. The group continued to build and test rocket engines until the outbreak of World War II. After 1945, the ARS became a professional society for engineers involved in astronautics. The ARS joined with other aeronautical engineering groups to form the American Institute of Aeronautics and Astronautics in 1963.

The first liquid-propellant rocket engines built by the American Rocket Society were machined from blanks of heat-resistant, cast-aluminum alloy. Engine No. 1 powered the first two rockets designed and constructed by the ARS. It featured combustion chamber walls 12.7 millimeters (½ inch) thick and burned liquid oxygen and gasoline to produce a thrust of 27.22 kilograms (60 pounds). Liquid oxygen was pressurized by partial evaporation, while bottled nitrogen forced gasoline from the tank to the engine.

ARS Engine No. 4, like its predecessors, was mounted in the nose, rather than the tail, of the rocket. The engine featured a single combustion chamber and four nozzles. The nozzles directed the jet gases to the rear and slightly away from the top of the gasoline tank on which the engine was mounted. The rocket powered by this engine was tested on September 9, 1934. It rose several hundred feet, at which point one of the nozzles burned out, bringing the flight to a close. In 1938, ARS member James Wyld suggested a cooling system whereby propellants circulate through a jacket surrounding the combustion chamber. Engines using this system are termed “regeneratively cooled.” The first Wyld rocket motor tested developed 41 kilograms (90 pounds) of thrust for 13½ seconds. It proved so successful that Wyld and other members of the ARS founded Reaction Motors, Inc., to produce and sell rocket engines based on this design.

The performance of motors developed by the ARS prior to World War II was measured on a test stand with built-in fuel and oxidizer tanks and bottled nitrogen gas. The engine was mounted on a carriage, and connected to the stand’s propellant tanks by flexible metal hoses. Thrust was indicated on a pressure gauge. The stand was first used in 1938.

All American Rocket Society artifacts are from G. E. Pendray and the American Institute of Aeronautics and Astronautics.

H-1 Engine

[Illustration: 51. A two-stage Saturn 1B rocket powered by H-1 engine cluster lifts off carrying Skylab 4 astronauts, November 16, 1973.]

The H-1 liquid-propellant rocket engine was an outgrowth of the LR-79 which served as the basic power plant for the USAF Thor missile. The H-1 was used in the 8-engine cluster of the first stage of the Saturn 1 and 1B launch vehicles.

The H-1 burns liquid oxygen and a grade of aviation kerosene to produce a total thrust of 92,986 kilograms (205,000 pounds). Each engine functions as an independent unit, with its own combustion chamber and turbopump, but fuel is drawn from common tanks.

The Saturn 1B was first launched on February 26, 1966, and most recently on July 15, 1975, in the launch of the U.S. crew of the Apollo-Soyuz Test Project.

It was developed by Rocketdyne, a division of North American Rockwell Corporation.

The engine on exhibit is from the National Aeronautics and Space Administration.

RL-10 Engine

[Illustration: 52. RL-10 engines used to power Centaur launch vehicle.]

The RL-10 is an upper stage propulsion system that can be stopped and restarted in space. It is a regeneratively cooled engine which burns liquid hydrogen and liquid oxygen to produce 6800 kilograms (15,000 pounds) of thrust. RL-10s pioneered the use of liquid hydrogen as a rocket fuel. They powered the Centaur launch vehicles that boosted such craft as Surveyor and Viking into space. A six-engine cluster of RL-10s was also used to propel the S4 stage of the Saturn 1.

The RL-10 was developed by Pratt & Whitney Aircraft division of the United Aircraft Corporation.

The RL-10 engine is from the National Aeronautics and Space Administration.

JATO Units

[Illustration: 53. JATO-boosted Martin Mariner aircraft.]

JATO (Jet Assisted Take-Off) rockets boost heavy aircraft from short runways or from high-altitude airports where long take-off runs are required. The development of more powerful airplane engines has reduced the use of JATOs in recent years.

The first American JATO units were tested at March Field, California, on August 12, 1941. Six solid-propellant engines, each developing 12.8 kilograms (28 pounds) of thrust, boosted a light plane piloted by Capt. Homer Boushey into the air on this occasion. These motors were designed and built by staff members of the Air Corps Jet Propulsion Research Project of the Guggenheim Aeronautical Laboratory of the California Institute of Technology.

During World War II, work continued on JATO prototypes: the M17G was developed by Reaction Motors, Inc., to provide 590 kilograms (1300 pounds) of thrust to assist the take-off of PBM flying boats; the M19G, also built by Reaction Motors, Inc., was fueled by gasoline with liquid oxygen as an oxidizer.

The liquid-propellant 25ALD1000, developed during World War II. produced 453 kilograms (1000 pounds) of thrust and burned red-fuming nitric acid as an oxidizer and aniline as a fuel. It was successfully used on a variety of aircraft, including the B-24, B-25, C-40, and P-38.

After the war ended, JATO engines were used on military aircraft such as the B-47 and F-84 in the United States, while in Britain the JATO Super Sprite became the first rocket engine to receive official type approval for quantity production.

The first U.S. JATO unit and the 25ALD1000 are gifts of the Aerojet General Division of the General Tire and Rubber Company. The M17G and M19G JATOs are from the Thiokol Chemical Corporation, and Rolls Royce, Ltd., provided the Super Sprite.

LR-87 Engine

[Illustration: 54. LR-87 engine in Titan on launch stand.]

The LR-87 was a twin-chamber liquid-propellant rocket engine developed to power the Titan I intercontinental ballistic missile. The engine developed a total thrust of 136,078 kilograms (300,000 pounds) at sea level. It burned liquid oxygen and a grade of aviation kerosene. The combustion chambers were gimbal mounted to allow them to swivel, controlling the missile trajectory during the powered phase of flight. The engine was developed by Aerojet General Corporation.

[Illustration: 55. LR-87 engine just after suspension in the museum.]

The LR-87 on exhibit is from the U.S. Air Force.

Toward 2076: The Future of Rocket Propulsion

[Illustration: 56. A 21st-century space colony in orbit between Earth and the Moon, as suggested by Dr. Gerard O’Neill of Princeton University. This colony could accommodate 200,000 persons, using solar energy for power and lunar or asteroid materials for construction. The teacup-shaped containers ringing the cylinder are agricultural stations, and the mirrors would direct sunlight into the interior, regulate the seasons, and control the day-night cycle.]

During the first twenty years of the space age, all launch vehicles were propelled by solid or liquid chemical rockets; however, nuclear and electric rocket motors are needed to provide the higher thrusts and velocities required for possible future manned journeys to other planets. Robert H. Goddard, the American rocket pioneer, was the first to suggest the possibility of electric rocket motors, but it was not until 1964 that electric rockets were actually tested in space.