International Ultraviolet Explorer
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What is the International Ultraviolet Explorer satellite?
The International Ultraviolet Explorer (IUE) was an astronomical research satellite created in the 1970s through a partnership between NASA, the Science and Engineering Research Council of the United Kingdom, and the European Space Agency (ESA). Launched on January 26, 1978, it operated until September 30, 1996, and proved to be a highly productive instrument.
IUE was a cylindrical satellite, 4.2 meters (13.8 feet) long, weighing 644 kg (1,420 pounds) at launch. It had telemetry units, a computer, batteries, and solar panels. Its 45-cm (17.7-inch) reflecting telescope featured two spectrographs linked to television cameras, covering ultraviolet wavelengths that the Earth's atmosphere blocks.
Operating from geosynchronous orbit, the IUE was controlled from ground stations in Spain and Maryland. It allowed astronomers to direct observations and inspect data in real time, much like a ground-based telescope. It observed planetary atmospheres, comets, stellar magnetic fields, and supernovas like Supernova 1987A.
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Why was the International Ultraviolet Explorer launched into space?
The International Ultraviolet Explorer (IUE) was launched as a collaborative project by the U.S. National Aeronautics and Space Administration (NASA), the Science and Engineering Research Council of the United Kingdom, and the European Space Agency (ESA).
The IUE, equipped with a telescope and spectrographs, was sent into space because Earth's atmosphere blocks ultraviolet wavelengths from reaching the ground. Functioning from January 26, 1978, until September 30, 1996, the IUE allowed astronomers to observe celestial objects such as comets and quasars and gather data about faint objects like nebulae and distant star clusters. It operated from geosynchronous orbit, enabling real-time observations and quick responses to transient targets like supernovas.
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What kind of light did the International Ultraviolet Explorer observe?
The International Ultraviolet Explorer (IUE) was an astronomical research satellite that observed space in a range of ultraviolet wavelengths that cannot reach ground-based telescopes due to the Earth’s atmosphere. The IUE's telescope was equipped with a 45-cm mirror, and it recorded data electronically down to 100 nm. The satellite, functioning from 1978 to 1996, had two spectrographs linked to television cameras. It studied celestial sources of ultraviolet radiation from a geosynchronous orbit.
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Which countries and organizations worked together to create the International Ultraviolet Explorer?
The International Ultraviolet Explorer (IUE) was a collaborative project involving the U.S. National Aeronautics and Space Administration (NASA), the Science and Engineering Research Council of the United Kingdom, and the European Space Agency (ESA). Launched on January 26, 1978, this astronomical research satellite operated until September 30, 1996, and is recognized as one of history's most productive astronomical instruments.
The IUE was designed to function as a satellite observatory that astronomers could use similarly to ground-based telescopes. It allowed astronomers to direct observations in real time and inspect data as it was collected.
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How did the International Ultraviolet Explorer send information back to scientists on Earth?
The International Ultraviolet Explorer (IUE) was an astronomical research satellite launched in 1978 as a collaborative project by NASA, the Science and Engineering Research Council of the United Kingdom, and the European Space Agency (ESA). The IUE had a 45-cm reflecting telescope with two spectrographs linked to television cameras. It observed space from geosynchronous orbit and was operated from ground stations at ESA’s Villafranca del Castillo Satellite Tracking Station near Madrid and NASA’s Goddard Space Flight Center in Maryland. Data was transmitted to the ground station at the end of each observing tour and examined immediately on a television monitor. All of the data collected by the IUE is preserved for use through archives established by the participating agencies.
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What important discoveries or contributions did the International Ultraviolet Explorer make to astronomy?
The International Ultraviolet Explorer (IUE), launched in 1978, was a collaborative project between NASA, the Science and Engineering Research Council of the United Kingdom, and the European Space Agency (ESA). Functioning until 1996, the IUE made significant contributions to astronomy, including knowledge of planetary atmospheres, the composition of comets, magnetic fields surrounding stars, stellar winds, the composition of planetary nebulae, the existence of hot galactic halos, physical conditions in the nuclei of active galaxies, and the nature of supernovas.
Among its notable achievements was the study of the rapidly changing ultraviolet spectrum of Supernova 1987A shortly after its discovery. Over its operational lifetime, thousands of astronomers utilized the IUE, resulting in over 2,500 scientific papers and more than 100,000 spectroscopic images.
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International Ultraviolet Explorer (IUE), astronomical research satellite built in the 1970s as a cooperative project of the U.S. National Aeronautics and Space Administration (NASA), the Science and Engineering Research Council of the United Kingdom, and the European Space Agency (ESA). Launched Jan. 26, 1978, the IUE functioned until it was shut down on September 30, 1996, and was one of the most productive astronomical instruments in history.
The cylindrical satellite measured 4.2 metres (13.8 feet) in length and weighed 644 kg (1,420 pounds) on launch. In addition to telemetry units, a computer, batteries, and a pair of solar panels for power, the IUE carried a 45-cm (17.7-inch) reflecting telescope equipped with two spectrographs linked to television cameras. The spectrographs covered a range of ultraviolet wavelengths that are prevented from reaching the ground by the Earth’s atmosphere.
The IUE observed space from geosynchronous orbit and was operated from ground stations at ESA’s Villafranca del Castillo Satellite Tracking Station near Madrid (8 hours per day) and NASA’s Goddard Space Flight Center in Maryland (16 hours per day). A primary goal in designing the IUE was to provide a satellite observatory that astronomers could use in the same manner as they might use a modern ground-based telescope—i.e., by directing observations in real time and inspecting data as it was collected. Among its strengths was the ability to respond quickly to transient targets such as comets and supernovas. Astronomers accessed the satellite through a competitive peer-review process that encouraged collaboration and time-sharing. Over its operational lifetime, thousands of astronomers used the IUE, publishing more than 2,500 scientific papers and collecting more than 100,000 spectroscopic images.
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IUE observations contributed to knowledge of planetary atmospheres, the composition of comets, magnetic fields surrounding stars, stellar winds and other aspects of the stellar environment, the composition of planetary nebulae, the existence of hot galactic halos, physical conditions in the nuclei of active galaxies, and the nature of supernovas—most notably the rapidly changing ultraviolet spectrum of Supernova 1987A, which became the focus of the IUE’s attention only hours after its discovery in the Large Magellanic Cloud in February 1987.
The IUE operated for almost 19 years, far beyond its expected three-year lifetime. Although it suffered minor mechanical and optical problems, it remained fully operational because project engineers were able to adapt its control systems to function under reduced capabilities. By the time it ceased scientific operations, an entire generation of astronomers had enjoyed access to the ultraviolet sky. All of the data collected by the IUE is preserved for use through archives established by the participating agencies.