Part 3

To continue the study of solar wind and interplanetary magnetic fields, _Explorer 12_ was orbited by a Delta launch vehicle on August 16, 1961. It was the first in a series of satellites to study energetic particles in space. These electrons and protons constitute the earth’s radiation belts and they affect weather and other phenomena on Earth.

_Atmosphere Explorer-A_ was the first of NASA’s aeronomy satellites. It was designed to remain in operation three months, studying the composition, density, pressure, and temperature of the upper atmosphere. This satellite discovered a belt of neutral helium atoms around the Earth.

Deriving its name from a spirit in Shakespeare’s play, _The Tempest_, _Ariel 1_ explored the ionosphere, a region of electrically charged air which begins about 40 kilometers (25 miles) above the surface of the Earth. Launched April 26, 1962, _Ariel_ was a cooperative venture between Great Britain and the United States. It was both the first British satellite and NASA’s first international satellite. The Royal Society’s British National Committee on Space Research coordinated the experimental program; NASA scientists and technicians built the craft.

Two small scientific laboratories, called Interplanetary Monitoring Platforms, were launched in 1967 to study the solar wind and other phenomena. IMP-E investigated interplanetary magnetic fields in the vicinity of the Moon. IMP-F investigated the interplanetary magnetic field also, in addition to the earth’s magnetosphere and radiation levels in space.

Interplanetary space between the Earth and Venus was the subject area for _Pioneer 5_, launched March 11, 1960. The satellite tested long-range communications systems, developed methods for measuring astronomical distances, studied the effects of solar flares, and performed other tasks before it went into orbit around the Sun.

With increasing interest in the earth’s space environment, a satellite was launched on September 7, 1967, to investigate the impact of space on biological processes. _Biosatellite 2_ was the second satellite in the program of three such vehicles. Frog eggs, plants, micro-organisms and insects were placed in orbit to enable scientists to study the combined effects of weightlessness, artificially produced radiation, and the absence of the normal day-night cycle on these organisms. Following two days in space, the capsule containing the experimental package reentered the atmosphere and was caught in mid-air by an Air Force recovery aircraft.

_Vanguard 1_ is from John P. Hagan. _Vanguard 3_, _Explorer 10_, _Explorer 12_, _AE-A_, _Ariel 1_, IMP-E & F, and _Biosatellite 2_ are from the National Aeronautics and Space Administration. The models of _Explorer 6_ and _Pioneer 5_ are from Space Technology Laboratories.

Meteorological Satellites

Weather forecasts are important to everyone—in planning whether or not to carry an umbrella, when to plant crops, when to evacuate riverbank areas. Nineteenth-century American meteorologists relied on local weather observations telegraphed to the Smithsonian Institution in Washington and then plotted on a large map of the nation from which forecasts were prepared.

When _Tiros-1_ returned the first global cloud-cover picture in 1960, meteorologists were on their way to more accurate forecasts. Since the satellite pictures offered more comprehensive weather data over a larger geographic area, the identification of weather patterns became more reliable.

While our knowledge of atmospheric conditions is still imperfect, we have learned to make reasonably accurate regional weather forecasts and to identify and track violent storms and hurricanes based on satellite information.

The TIROS series (Television Infrared Observations Satellites) were designed to test the feasibility of weather observation from orbit. The TIROS satellite on exhibit was the prototype for the entire series of vehicles. The prototype made eight trips to the launch stand at Cape Kennedy, where it was used to check communications and handling procedures prior to the launch of the scheduled TIROS. All 10 TIROS satellites were successful. Launched between April 1, 1960, and July 1, 1965, they carried a variety of camera systems for experimental purposes.

Nine TIROS Operational Satellites (TOS) followed _TIROS 1-10_. Except for the first TOS, these satellites flew in pairs with one craft storing pictures on board for later transmission to major receiving centers, while the other broadcast its photographs continuously to any ground station within range. The satellite on display is of the latter type. These vehicles were launched between 1966 and 1969. They were placed in near-polar orbits by reliable Thor-Delta launch vehicles.

After launch, TOS vehicles were referred to as ESSA satellites. ESSA was an acronym both for Environmental Survey Satellite and for the Environmental Science Service Administration, the federal agency that operated the spacecraft. This organization became a part of the National Oceanic and Atmospheric Administration which currently has responsibility for operational meteorological satellite programs.

From about 1392 kilometers (865 miles) above Earth, two wide-angle television cameras mounted on either side of the spacecraft took in 10.4-million square kilometers (4-million square miles) per photo.

The Improved TIROS Operational Satellite (ITOS) opened the world of radiometric measurement to meteorologists—information about surface temperatures on the ground, at sea level, or at the cloud tops obtained by scanning devices sensitive to energy that is invisible to the naked eye. ITOS spacecraft could return accurate day or night surface and cloud-cover images. Seven of these satellites were launched between 1970 and 1973.

_TIROS_ was presented to the National Air and Space Museum by the National Aeronautics and Space Administration; _TOS_ is from the National Oceanic and Atmospheric Administration; _ITOS_ is from the Astro-Electronics Division of RCA, Inc.

Communications Satellites

Communications satellites can be grouped into two broad categories. Passive vehicles reflect signals from one ground station to another. Active satellites accept ground signals and either amplify and rebroadcast them immediately or record messages for later transmission.

The Echo satellite balloons typified the passive category of communications spacecraft. These satellites “bounced” radio signals from one ground station to another. Uninflated Echo payloads were carried into orbit packed in special storage containers. When released in space, the balloon was inflated by chemicals packed inside which subliminated to produce inflating gas. The mylar plastic skin of the satellite was sandwiched between two layers of aluminum foil. _Echo 2_—on display—included a system for releasing gas over a long period of time to maintain the satellite’s spherical shape. Launched January 25, 1964, _Echo 2_ was the first satellite used for communication experiments between the United States and the Soviet Union.

Project West Ford, launched May 9, 1963, was a unique experiment in passive satellite communications. It was not a solid vehicle, but a series of 400-million tiny individual copper filaments called dipoles. The dipoles formed a reflective layer some 64,300 kilometers (40,000 miles) long, 32 kilometers (20 miles) thick, and 32 kilometers (20 miles) wide. The distance between the individual dipoles averaged 536 meters (one-third mile). The West Ford experiment proved disappointing, and advances in the design of active communications satellites made further experiments of this nature unnecessary.

_Oscar 1_ (Orbital Satellite Carrying Amateur Radio) was conceived, designed, and constructed by American amateur radio “hams.” Launched as a “piggyback” satellite on December 12, 1963, Oscar transmitted a series of Morse code dots spelling “hi.” The message was picked up by 5000 operators in 28 nations during the 18 days of transmission. Oscar investigated radio propagation phenomena in space on that portion of the radio frequency spectrum allocated to amateur radio (144-146 megaherz).

Testing the use of a “delayed-repeater” satellite in global military communications, _Courier 1-B_ was placed in a high-altitude orbit on October 4, 1960. The craft accepted and stored messages as it passed over one ground station, then replayed them on command.

_Relay_, another active repeater satellite, was placed in orbit on December 13, 1962. _Relay_ carried communications experiments to test a variety of relay equipment—including that for photofacsimile, teleprinter, and data transmission. During its 25-month lifespan, _Relay 1_ introduced the nations of the world to satellite communication. A second, improved _Relay_ was launched in 1964.

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

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.)

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

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

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

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