[PDF] Orbital Decay And Lifetime For Earth Satellites eBook

Author : D. G. King-Hele
Publisher :
Page : 56 pages
File Size : 16,27 MB
Release : 1977
Category :
ISBN :

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The accurate prediction of satellite decay dates some months or years ahead remains one of the most difficult and intractable problems of orbital mechanics, chiefly because the lifetime depends strongly on the future variations in air density, which are at present not accurately predictable. In this paper simple graphical methods are presented for estimating the future lifetime of an Earth satellite from its current rate of decay, using theory adapted to an atmosphere with a realistic variation of density with height. The effects of the departure of the Earth and atmosphere from spherical symmetry, and the variations of density with time, are approximated by specifying correction factors. Orbits which experience serious lunisolar perturbations call for numerical-integration methods, and the uses of the computer programs PROD and PTDEC are described. Despite the many uncertainties, the remaining lifetimes of most satellites should be predictable with an accuracy of + or - 10% by these methods, which are based on many years' experience in making the monthly decay predictions for the RAE Table of satellites. (Author).

Author : National Research Council
Publisher : National Academies Press
Page : 225 pages
File Size : 16,59 MB
Release : 1995-07-07
Category : Science
ISBN : 0309051258

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Since the beginning of space flight, the collision hazard in Earth orbit has increased as the number of artificial objects orbiting the Earth has grown. Spacecraft performing communications, navigation, scientific, and other missions now share Earth orbit with spent rocket bodies, nonfunctional spacecraft, fragments from spacecraft breakups, and other debris created as a byproduct of space operations. Orbital Debris examines the methods we can use to characterize orbital debris, estimates the magnitude of the debris population, and assesses the hazard that this population poses to spacecraft. Potential methods to protect spacecraft are explored. The report also takes a close look at the projected future growth in the debris population and evaluates approaches to reducing that growth. Orbital Debris offers clear recommendations for targeted research on the debris population, for methods to improve the protection of spacecraft, on methods to reduce the creation of debris in the future, and much more.

Author : H. B. Wackernagel
Publisher :
Page : 8 pages
File Size : 14,58 MB
Release : 1959
Category : Artificial satellites
ISBN :

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The decay of the orbit of most artificial earth satellites can be described by the simple formula log N = R (log delta P sub N + Q) N is the revolution number reckoned backwards from the revolution of decay and delta P sub N a quantity defined in the text. The parameters R and Q are correlated to the ratio m/F of mass and effective cross section and to the height of the perigee q, respectively. (Author).

Author : National Research Council
Publisher : National Academies Press
Page : 178 pages
File Size : 21,75 MB
Release : 2011-12-16
Category : Science
ISBN : 0309219744

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Derelict satellites, equipment and other debris orbiting Earth (aka space junk) have been accumulating for many decades and could damage or even possibly destroy satellites and human spacecraft if they collide. During the past 50 years, various National Aeronautics and Space Administration (NASA) communities have contributed significantly to maturing meteoroid and orbital debris (MMOD) programs to their current state. Satellites have been redesigned to protect critical components from MMOD damage by moving critical components from exterior surfaces to deep inside a satellite's structure. Orbits are monitored and altered to minimize the risk of collision with tracked orbital debris. MMOD shielding added to the International Space Station (ISS) protects critical components and astronauts from potentially catastrophic damage that might result from smaller, untracked debris and meteoroid impacts. Limiting Future Collision Risk to Spacecraft: An Assessment of NASA's Meteoroid and Orbital Debris Program examines NASA's efforts to understand the meteoroid and orbital debris environment, identifies what NASA is and is not doing to mitigate the risks posed by this threat, and makes recommendations as to how they can improve their programs. While the report identified many positive aspects of NASA's MMOD programs and efforts including responsible use of resources, it recommends that the agency develop a formal strategic plan that provides the basis for prioritizing the allocation of funds and effort over various MMOD program needs. Other necessary steps include improvements in long-term modeling, better measurements, more regular updates of the debris environmental models, and other actions to better characterize the long-term evolution of the debris environment.