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Mariner |
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MarinerAny of a series of unmanned U.S. space probes sent near Venus, Mars, and Mercury. Mariners 2 (1962) and 5 (1967) passed Venus within 22,000 mi (35,000 km) and 2,500 mi (4,000 km), respectively, and made measurements of temperature and atmospheric density. Mariners 4 (1965), 6 and 7 (1969), and 9 (1971–72) obtained striking photographs of the surface of Mars and analyzed its atmosphere and magnetic field. Mariner 10 is the only spacecraft ever to have visited Mercury (1974–75). Mariner the name of a series of American unmanned space probes designed to investigate Venus and Mars, and also of their development and launch program (see Tables la and Ib). Work on the Mariner program began in 1960. The first probes were built for fly-bys and were basically of the same type, with the exception of Mariners 1 and 2, which were designed on the basis of previously developed Ranger lunar units. The Mariner stations carried radioelectronic equipment, a programming and timing device, an attitude-stabilization system, a power unit, a temperature-control system, a vernier engine, and television cameras (with the exception of Mariners 1 and 2). Numerous scientific instruments were installed in the Mariners: a magnetometer to measure magnetic field intensity, an ionization chamber to study cosmic rays, a solar-plasma detector to record protons, and a meteoric-particle detector to determine the momentum of meteoric particles and study their distribution near the earth (Mariners 1-5). The set of radiation detectors consisted of three Geiger counters, an ultraviolet photometer, and a sounding receiver. Mariners 8 and 9 were designed on the basis of the Mariner 6 and 7 probes, and they also carried an ultraviolet spectrometer for determining the gaseous composition of the atmosphere and ionosphere (in particular, ozone distribution) and for investigating the hydrogen corona, and an infrared spectrometer for determining the temperature of the lower layers of the atmosphere, studying the distribution of water vapor, recording substances present in the atmosphere in small quantities, and studying the surface of the planet. An infrared radiometer was used to determine thermal inertia (the rate of cooling and heating) and the composition of the surface, to search for thermal anomalies, and to obtain data used in analyzing television images of the surfaces of the planets. Mariners 8 and 9 also carried radio sounding units operating on various frequencies, a set of sensors (a “telescope”) for recording cosmic rays, and an X-ray detector. The boosters for the Mariner probes were the Atlas-Agena B (Mariners 1 and 2), Atlas-Agena D (Mariners 3-5) and Atlas-Centaur (Mariners 6-10). G. A. NAZAROV Want to thank TFD for its existence? Tell a friend about us, add a link to this page, add the site to iGoogle, or visit the webmaster's page for free fun content. |
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