$Unique_ID{USH00018} $Pretitle{2} $Title{NASA, The First 25 Years 1958-1983 Chapter 3 Applications Satellites} $Subtitle{} $Author{Thorne, Muriel M., Technical Monitor & Editor} $Affiliation{NASA} $Subject{satellites satellite earth first communications weather nasa surface landsat resources} $Volume{} $Date{1983} $Log{} Book: NASA, The First 25 Years 1958-1983 Author: Thorne, Muriel M., Technical Monitor & Editor Affiliation: NASA Date: 1983 Chapter 3 Applications Satellites When the first satellites were launched in the late 1950's, many people were skeptical about the practical value of a space program. In just three years, however observations and measurements from Earth-orbiting satellites were revolutionizing communications and weather forecasting and showing Earth on a global scale. These were the applications satellites, spacecraft with experiments and instruments that provided unique, direct benefits to life on Earth. They and those that evolved from them have made it possible for people on opposite sides of Earth to communicate instantaneously, for people in remote areas of the world to learn by television, for ships to know where storms and icebergs threaten passage, for forecasters to watch weather develop, for oil companies to locate drilling sites, for environmentalists to monitor the spread of pollutants. In both domestic and foreign applications satellite programs, NASA has contributed research and development, launching capabilities, and evaluation of spacecraft. The technologies developed produced passive and active communications satellites, the first synchronous and geostationary orbits, and the cloud cover pictures that now are a regular feature of daily weather reports. From Echo, the balloon that was the first satellite everyone could see, and the scientific Explorer 6 that also took the first crude cloud cover picture, the applications satellites have become complex multipurpose systems. Once NASA has developed the weather and communications satellites, the responsibility for operating them falls to other government agencies or to private industry. NASA continues its research role, seeking and developing advanced technologies. The following list introduces the major groups of these satellites, their purposes, and the benefits they have contributed. Communications In 1945 British scientist and science fiction writer, Arthur C. Clarke, published a technical paper in which he suggested that communications satellites were feasible. Fifteen years later, NASA launched its first communications satellite, Echo, a silvery balloon that orbited Earth every 114 minutes. Echo was a passive satellite that reflected radio signals back to Earth. Two years later, Relay, the first active satellite was launched to receive signals, amplify them, and transmit them back to Earth. Today's split-second global communications by voice, television, and computer are such a part of daily life that the evolution from simple passive reflectors to complex active transmitters is hardly remembered. After NASA completed research and development, private companies produced their own communications satellites, and in 1962 Congress authorized the Communications Satellite Corporation, Comsat, which is the U.S. representative in and manager of Intelsat, the International Telecommunications Satellite Organization. For both industry and Intelsat, NASA launches and tracks satellites on a cost-reimbursable basis. Echo The Echos were inflated in space to spherical balloons of aluminized Mylar, 30.5 and 40 meters (100 and 135 feet) in diameter, respectively. Passive communications satellites, they reflected radio signals between ground stations. They also provided information about the density of the upper atmosphere. Echo 1 was launched August 12, 1960, Echo 2 in January 1964. Relay Relay 1 was NASA's first active repeater experimental satellite; launched December 13, 1962, it handled 12 simultaneous two-way telephone conversations or one television channel and provided the first satellite communications link between North and South America and Europe. Relay 2, an improved version, was launched in January 1964. Syncom Three experimental, active satellites; the name, coined from the first syllables of "synchronous communications," referred to their orbits. Weight: 38.5 kg (about 85 lbs) each. Syncom I February 14, 1963 In nearly synchronous orbit, but communications failed. Syncom II July 26, 1963 First satellite placed in synchronous orbit. Many successful intercontinental communication experiments. Syncom III August 19, 1964 First stationary Earth satellite. Demonstrated the practicality and effectiveness of stationary, active communication satellites. In orbit near the International Dateline, it was used to telecast the 1964 Olympic Games in Tokyo to the United States, the first television program to cross the Pacific. Applications Technology Satellites (ATS) A series of six multipurpose Applications Technology Satellites designed to test new space instruments and demonstrate new satellite technologies, particularly those used in synchronous orbit satellites. ATS-1 December 6, 1966 Took first U.S. high-quality photographs of Earth from synchronous orbit, showing changing cloud-cover patterns. Also relayed color television across the U.S. and was the first satellite to permit two-way VHF communication between ground and aircraft in flight. ATS-3 November 1967 Carried advanced communications, meteorology, and navigation experiments; transmitted color images of one complete side of Earth. ATS-6 May 1974 The first communications satellite with power to broadcast TV photos to small local receivers; also used for a number of experimental public health and education telecasts to remote rural areas in the U.S. and India. (See Chapter IV, India.) Communications Technology Satellite (CTS) January 17, 1976 The CTS was a joint project with Canada. A high-powered satellite, it used a movable terminal to investigate the possibility of transmitting public service information to small, inexpensive antennas in remote locations. Earth Resources Earth observation satellites have brought us a new view of our planet. Mountains, prairies, deserts, lakes, rivers, reservoirs, forests, farms, cities, highways, have become infrared and ultraviolet scenes. Millions of these pictures have been distributed to users of Earth resources information around the world. From the outset, the remote sensory devices of these spacecraft have produced a continuous flow of data. The results, including often dramatic pictures, have been tangible and the satellites unique tools of enormous practical value for a wide range of interests: urban development and land use and water source management, agriculture, locating pollution, geology, forestry, mapping and charting. Geologists use the data to locate drilling sites, to predict earthquakes, and to study volcanoes. Skilled photointerpreters among agriculturists can readily distinguish among a variety of crops in the satellite images. With computers, maps can be produced showing the precise location of each crop over large areas of land. Using this technology, NASA participated in a three-year experiment to monitor global wheat production beginning in 1974. The Large Area Crop Inventory Experiment (LACIE) successfully tested several techniques for predicting crop production early in the growing season. Much of the everyday disposal of tons of garbage and trash and toxic wastes dumped into the environment ends up in our rivers, lakes, and oceans. The challenge to clean up polluted areas and to protect those areas yet untouched requires information on a scale that was unavailable before satellites. Earth resources spacecraft have provided valuable surveys of large areas of land, helping scientists and environmentalists trace the sources of pollution and monitor the dissemination of waste. Wise management of the Earth's water resources is necessary for both present and future generations. Data from satellites has been helping hydrologists to predict floods and estimate flood damage, as well as to monitor water supplies. From the simple PAGEOS balloon of 1966 to the advanced Landsat 4 of 1982, the Earth resources experiments have changed radically the way we see Earth, collect information about it, and interpret the results. Passive Geodetic Earth Orbiting Satellite (PAGEOS) June 1966 A large metalized balloon, 30 meters (98.4 ft) in diameter similar to the Echo satellites. A passive satellite, it reflected sunlight and, photographed by ground stations around the world, established a worldwide triangulation network to map Earth's surface. Landsat A series of satellites that have provided a wealth of observations which have improved our ability to monitor and understand the dynamics and character of the various features and materials covering the surface of the Earth. Landsat 1, July 1972 Landsat 2, January 1975 Landsat 3, March 1978 The first Landsats (1 and 2 were originally called ERTS for Earth Resources Technology Satellite) carried an Earth-viewing sensor called Multispectral Scanner (MSS), a radiometer that obtains imagery of Earth's surface in four discrete spectral bands. The decade of their image-collecting showed the unique types of data that MSS imagery could provide vegetation types, bare soil and rock conditions, snow cover - on a highly repetitive basis. The images Landsats 1, 2, and 3 collected represent the first historical record of Earth's global surface conditions. Landsat 1 was removed from service in 1978, Landsat 2 in 1982, and Landsat 3 will be retired in 1983. Landsat 4, July 1982 In addition to the MSS, Landsat 4 has a more sophisticated sensor, the Thematic Mapper (TM) which measures the intensity of surface radiation in seven discrete bands and has approximately twice the spectral resolution, three times the spatial resolution, and four times the sensitivity of the MSS. From a 695-kilometer (432-mi) orbit, it is providing extraordinary details, and for the first time, natural color images, of Earth's surface features. NASA has transferred the operation and management of Landsat to the National Oceanic and Atmospheric Administration (NCAA). Management control over the TM will be retained during the experimental research and development phase of the new sensor system; NASA expects to transfer control of the TM to NCAA in early 1985. Landsat imagery is available for a lab service charge. For information about ordering pictures, write to the EROS Data Center, Sioux Falls, SD 57198. Earth Resources Experiment Package (EREP) SKYLAB, May 1973-February 1974 Objectives: To test the use of sensors operating in the visible and infrared portions of the spectrum, to test a complex microwave sensor that provided a space-based radar system for Earth resource studies, and to develop data analysis techniques. Investigations: Agriculture, range, and forestry; land use and cartography; geology and hydrology; oceans and atmosphere. Results: Demonstrated the potential and practicality of using quality photos from orbiting spacecraft for large geographic as well as regional and local areas and their usefulness as a tool for professionals concerned with management of resources. Laser Geodynamics Satellite (LAGEOS) May 1976 A heavy sphere, 411 kg (906 lbs), 60 centimeters (2 ft) across and covered with laser reflectors, designed to demonstrate the feasibility and utility of a ground-to-satellite laser system to contribute to the study of solid Earth dynamics; provided valuable data to scientists analyzing conditions leading to earthquakes. Heat Capacity, Mapping Mission (HCMM) April 1978 First in a series of small experimental satellites designed for the Applications Explorer Missions. Later called AEM-1, it had one sensor for one purpose, making thermal measurements of Earth's surface and atmosphere across the U.S. Its unique sensor could read daytime temperatures associated with the Sun and nighttime temperatures associated with radiative cooling. Meteorology Weather affects everyone - food supplies, travel, recreation - and along with other applications satellites, the weather satellites have brought special advantages to life on Earth. They enable people to plan ahead, assist meteorologists with forecasting, and help scientists to understand better the air around us. Advance knowledge of weather systems that can be disastrous is the most striking advantage; part of that knowledge comes from the ability to see the sparsely populated regions of the world where weather is born, thus aiding long-term prediction. For local meteorologists, daily photographs show how their local weather patterns fit into the overall picture. On April 1, 1960, TIROS 1, the first true weather satellite, was launched. With each succeeding generation of satellites, remote sensing instruments became increasingly sophisticated and today's high quality pictures are a far cry from the first tentative trials. TIROS The Television and Infrared Observation Satellite (TIROS) was a simple hatbox-shaped craft carrying special television cameras that viewed Earth's cloud cover from a 725-km (450-mi) orbit. The pictures radioed back to Earth provided meteorologists with a new tool - a nephanalysis, or cloud chart. By 1965, nine more TIROS satellites were launched. They had progressively longer operational times, carried infrared radiometers to study Earth's heat distribution, and several were placed in polar orbits to increase picture coverage over the first TIROS in its near-equatorial orbit. TIROS 8 had the first Automatic Picture Transmission (APT) equipment that allowed pictures to be sent back right after they were taken instead of having to be stored for later transmission. Eventually, APT pictures could be received on fairly simple ground stations anywhere in the world, even in high school classrooms. TIROS 9 and 10 were test satellites of improved configurations for the Tiros Operational Satellite (TOS) system. (When it became part of another acronym, TIROS was written Tiros.) Operational use started in 1966. In orbit, the TOS satellites were called ESSA for the Environmental Sciences Services Administration, the government agency that financed and operated them. TOS satellites were placed in Sun-synchronous orbits, so they passed over the same position on Earth's surface at exactly the same time each day; this allowed meteorologists to view local cloud cover changes on a 24-hour basis. Several ITOS (for Improved TOS satellites) have been launched since 1970 and are the workhorses of the meteorologists. In orbit they are called NOAA for the National Oceanographic and Atmospheric Administration which is responsible for their operation. Nimbus More complex than TIROS, Nimbus was a second-generation research satellite. Each carried advanced cameras, an APT system, an advanced TV cloud mapping camera system, and an infrared radiometer that allowed pictures at night for the first time. Seven were placed in orbit between 1964 and 1978. Nimbus 3, launched in April 1969, provided data for the U.S. portion of the Global Atmospheric Research Program (GARP), an international program formulating and coordinating research for achieving long-range global weather forecasting. The Nimbus satellites tested space-borne meteorological equipment and their experiments led to operational, 24-hour satellite weather coverage. Applications Technology Satellites (ATS) Intended primarily for communications technology, these multipurpose spacecraft contributed much to advance weather forecasting. ATS-1 December 1966 Took repetitive photographs of the same area, greatly aiding in the early detection of severe storms. ATS-3 November 1967 Recorded the first color images of the full Earth disc. Took photos every 20 minutes enabling meteorologists to put them together in a sequence and make a motion picture of cloud movements; until 1975, the cloud cover pictures seen on TV came from this satellite. Synchronous Meteorological Satellites (SMS-1 and 2) May 1974 and February 1975 First experimental craft for a geosynchronous satellite system designed specifically to provide weather data and to serve as prototypes for later operational satellites funded by NOAA. Following launch and check out by NASA, SMS-1 and SMS-2 were transferred to NOAA for use in the National Operational Meteorological Satellite System. Successive satellites, designated GOES (Geostationary Operational Environmental Satellite), were constructed and launched by NASA, funded and operated by NOAA. Oceanography Seventy percent of Earth is covered by oceans. These vast areas of water are a source of energy in the form of weather the home of great schools of fish, a mechanism for the disposal of waste products, and the major means of transporting the goods of the world by ship. Precise knowledge of the oceans resources and dynamics has potential application in many scientific and commercial pursuits - ship design and port development, fishing, weather forecasting, environmental science, shipping, selection of sites for off-shore drilling. Satellite observations have contributed to our understanding with accurate measurements of surface wind speeds and directions, temperatures, wave heights, and tides and currents; the data have helped to detect storms, map the ocean floor, and monitor the movement of icebergs. Earth Resources Experiment Package (EREP) Skylab, May 1973-February 1974 A collection of instruments with relatively low-resolution, middle-spectrum imaging sensors, EREP proved the feasibility of remote-sensing of wind conditions, surface temperatures and roughness, and the recording of visible phenomena, and advanced the study of the interaction of the atmosphere and land and ocean surfaces. Improved versions of the instruments were built for GEOS-3 and Seasat. Geodynamic Experimental Ocean Satellite (GEOS-3) April 1975 Measured the changing shape of the oceans surface, tides, and currents to improve the geodetic model of Earth and knowledge of Earth-sea interactions. Third in the series of Geodetic Earth Orbiting Satellites (GEOS), GEOS-3 was renamed Geodynamic Experimental Ocean Satellite to emphasize its specific mission in NASA's ocean physics program while retaining the GEOS acronym. Seasat (Specialized Experimental Applications Satellite) June 26, 1978 First satellite for sole study of the oceans in a proof-of-concept mission. Objectives: To demonstrate techniques for monitoring Earth's oceanographic phenomena and features from space on a global scale; to provide oceanographic data in a timely fashion to scientists and commercial users; and to determine the key features of an operational ocean monitoring system. With all-weather and day-night capability, it circled Earth 14 times a day and crossed 95 percent of the ocean's surface every 36 hours giving oceanographers their first worldwide observation of the seas. Although contact was lost in October 1978 and the mission terminated in November, the objectives were largely met. For The Classroom 1. Research topics: History of communications Commercial satellites The development of Earth resources satellites Sources of pollution in the at mosphere 2. What advantage does geological study from space have over study from Earth's surface? from Earth over study from space? 3. Why is a study of the atmosphere important? 4. Secondary school teachers may obtain a copy of Teachers' Guide for Building and Operating Weather Satellite Ground Stations from the Educational Programs Officer NASA Goddard Space Flight Center (202.3), Greenbelt, MD 20771. The publication gives the information needed to construct, modify, and operate a weather satellite recording station. 5. Have your students list the possible benefits of Earth resources satellites; which are apparent in their local community? their state?