Author: D. G. King-Hele
Publisher:
ISBN:
Category : Artificial satellites
Languages : en
Pages : 20
Book Description
The chief variations in upper-atmosphere density are described, and it is shown how each of them affects the orbits of close Earth satellites. The main features discussed are: (1) the irregular variations in density dependent on solar activity, which may cause great changes in a few days, as well as a 27-day recurrence tendency; (2) the day-to-night and semi-annual variations in density, which cause nearly-periodic changes in orbits: for the day-to-night variation the period is usually between 2 months and 2 years, while the semi-annual effect leads to maxima of density in April and October, and minima in January and July; and (3) the large changes in density during a sunspot cycle, which give rise to a 10- or 11-year recurrence tendency. The changes in orbital inclination caused by the rotation of the atmosphere are also described. (Author).
The Upper Atmosphere and Its Influence on Satellite Orbits
Author: D. G. King-Hele
Publisher:
ISBN:
Category : Artificial satellites
Languages : en
Pages : 20
Book Description
The chief variations in upper-atmosphere density are described, and it is shown how each of them affects the orbits of close Earth satellites. The main features discussed are: (1) the irregular variations in density dependent on solar activity, which may cause great changes in a few days, as well as a 27-day recurrence tendency; (2) the day-to-night and semi-annual variations in density, which cause nearly-periodic changes in orbits: for the day-to-night variation the period is usually between 2 months and 2 years, while the semi-annual effect leads to maxima of density in April and October, and minima in January and July; and (3) the large changes in density during a sunspot cycle, which give rise to a 10- or 11-year recurrence tendency. The changes in orbital inclination caused by the rotation of the atmosphere are also described. (Author).
Publisher:
ISBN:
Category : Artificial satellites
Languages : en
Pages : 20
Book Description
The chief variations in upper-atmosphere density are described, and it is shown how each of them affects the orbits of close Earth satellites. The main features discussed are: (1) the irregular variations in density dependent on solar activity, which may cause great changes in a few days, as well as a 27-day recurrence tendency; (2) the day-to-night and semi-annual variations in density, which cause nearly-periodic changes in orbits: for the day-to-night variation the period is usually between 2 months and 2 years, while the semi-annual effect leads to maxima of density in April and October, and minima in January and July; and (3) the large changes in density during a sunspot cycle, which give rise to a 10- or 11-year recurrence tendency. The changes in orbital inclination caused by the rotation of the atmosphere are also described. (Author).
Space Physics and Aeronomy, Space Weather Effects and Applications
Author: Anthea J. Coster
Publisher: John Wiley & Sons
ISBN: 111950757X
Category : Science
Languages : en
Pages : 243
Book Description
Examines how solar and terrestrial space phenomena affect sophisticated technological systems Contemporary society relies on sophisticated technologies to manage electricity distribution, communication networks, transportation safety, and myriad other systems. The successful design and operation of both ground-based and space-based systems must consider solar and terrestrial space phenomena and processes. Space Weather Effects and Applications describes the effects of space weather on various present-day technologies and explores how improved instrumentation to measure Earth's space environment can be used to more accurately forecast changes and disruptions. Volume highlights include: Damage and disruption to orbiting satellite equipment by solar particles and cosmic rays Effects of space radiation on aircraft at high altitudes and latitudes Response of radio and radar-based systems to solar bursts Disturbances to the propagation of radio waves caused by space weather How geomagnetic field changes impact ground-based systems such as pipelines Impacts of human exposure to the space radiation environment The American Geophysical Union promotes discovery in Earth and space science for the benefit of humanity. Its publications disseminate scientific knowledge and provide resources for researchers, students, and professionals. Find out more about the Space Physics and Aeronomy collection in this Q&A with the Editors in Chief
Publisher: John Wiley & Sons
ISBN: 111950757X
Category : Science
Languages : en
Pages : 243
Book Description
Examines how solar and terrestrial space phenomena affect sophisticated technological systems Contemporary society relies on sophisticated technologies to manage electricity distribution, communication networks, transportation safety, and myriad other systems. The successful design and operation of both ground-based and space-based systems must consider solar and terrestrial space phenomena and processes. Space Weather Effects and Applications describes the effects of space weather on various present-day technologies and explores how improved instrumentation to measure Earth's space environment can be used to more accurately forecast changes and disruptions. Volume highlights include: Damage and disruption to orbiting satellite equipment by solar particles and cosmic rays Effects of space radiation on aircraft at high altitudes and latitudes Response of radio and radar-based systems to solar bursts Disturbances to the propagation of radio waves caused by space weather How geomagnetic field changes impact ground-based systems such as pipelines Impacts of human exposure to the space radiation environment The American Geophysical Union promotes discovery in Earth and space science for the benefit of humanity. Its publications disseminate scientific knowledge and provide resources for researchers, students, and professionals. Find out more about the Space Physics and Aeronomy collection in this Q&A with the Editors in Chief
The Effect of Atmospheric Winds on Satellite Orbits of High Eccentricity
Author: D. G. King-Hele
Publisher:
ISBN:
Category :
Languages : en
Pages : 32
Book Description
The orbits of Earth satellites with perigee heights less than 600km are liable to be appreciably perturbed by the aerodynamic forces resulting from winds in the upper atmosphere, and analysis of the changes in the orbits provides a method of determining zonal (west-to-east) and meridional (north-to-south) winds. The theory hitherto used has been developed for orbits of eccentricity e 0.2. Here we develop the theory for the effect of zonal and meridional winds on the inclination i and right ascension of the node omega for satellites in orbits with e 0.2 moving in an oblate atmosphere. The results are expressed in terms of the change in orbital period, which is accurately known for actual satellites, so that the equations are independent of variations in air density and satellite cross-sectional area.
Publisher:
ISBN:
Category :
Languages : en
Pages : 32
Book Description
The orbits of Earth satellites with perigee heights less than 600km are liable to be appreciably perturbed by the aerodynamic forces resulting from winds in the upper atmosphere, and analysis of the changes in the orbits provides a method of determining zonal (west-to-east) and meridional (north-to-south) winds. The theory hitherto used has been developed for orbits of eccentricity e 0.2. Here we develop the theory for the effect of zonal and meridional winds on the inclination i and right ascension of the node omega for satellites in orbits with e 0.2 moving in an oblate atmosphere. The results are expressed in terms of the change in orbital period, which is accurately known for actual satellites, so that the equations are independent of variations in air density and satellite cross-sectional area.
The Upper Atmosphere Research Satellite In-Flight Dynamics
Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781723453878
Category :
Languages : en
Pages : 104
Book Description
Upper Atmosphere Research Satellite flight data from the first 737 days after launch (September 1991) was used to investigate spacecraft disturbances and responses. The investigation included two in-flight dynamics experiments (approximately three orbits each). Orbital and configuration influences on spacecraft dynamic response were also examined. Orbital influences were due to temperature variation from crossing the Earth's terminator and variation of the solar incident energy as the orbit precessed. During the terminator crossing, the rapid ambient temperature change caused the spacecraft's two flexible appendages to experience thermal elastic bending (thermal snap). The resulting response was dependent upon the orientation of the solar array and the solar incident energy. Orbital influences were also caused by on-board and environmental disturbances and spacecraft configuration changes resulting in dynamic responses which were repeated each orbit. Configuration influences were due to solar array rotation changing spacecraft modal properties. The investigation quantified the spacecraft dynamic response produced by the solar array and high gain antenna harmonic drive disturbances. The solar array's harmonic drive output resonated two solar array modes. Friction in the solar array gear drive provided sufficient energy dissipation which prevented the solar panels from resonating catastrophically; however, the solar array vibration amplitude was excessively large. The resulting vibration had a latitude-specific pattern. Woodard, Stanley E. Langley Research Center UPPER ATMOSPHERE RESEARCH SATELLITE (UARS); DYNAMIC RESPONSE; SPACECRAFT CONFIGURATIONS; SOLAR ARRAYS; VIBRATION EFFECTS; SPACECRAFT ORBITS; SOLAR ENERGY; ELASTIC BENDING; TEMPERATURE EFFECTS; ANTENNA COMPONENTS; FRICTION; ENERGY DISSIPATION; SATELLITE ATTITUDE CONTROL; ORBITAL MECHANICS; APPENDAGES; ROTATION; MECHANICAL DRIVES...
Publisher: Createspace Independent Publishing Platform
ISBN: 9781723453878
Category :
Languages : en
Pages : 104
Book Description
Upper Atmosphere Research Satellite flight data from the first 737 days after launch (September 1991) was used to investigate spacecraft disturbances and responses. The investigation included two in-flight dynamics experiments (approximately three orbits each). Orbital and configuration influences on spacecraft dynamic response were also examined. Orbital influences were due to temperature variation from crossing the Earth's terminator and variation of the solar incident energy as the orbit precessed. During the terminator crossing, the rapid ambient temperature change caused the spacecraft's two flexible appendages to experience thermal elastic bending (thermal snap). The resulting response was dependent upon the orientation of the solar array and the solar incident energy. Orbital influences were also caused by on-board and environmental disturbances and spacecraft configuration changes resulting in dynamic responses which were repeated each orbit. Configuration influences were due to solar array rotation changing spacecraft modal properties. The investigation quantified the spacecraft dynamic response produced by the solar array and high gain antenna harmonic drive disturbances. The solar array's harmonic drive output resonated two solar array modes. Friction in the solar array gear drive provided sufficient energy dissipation which prevented the solar panels from resonating catastrophically; however, the solar array vibration amplitude was excessively large. The resulting vibration had a latitude-specific pattern. Woodard, Stanley E. Langley Research Center UPPER ATMOSPHERE RESEARCH SATELLITE (UARS); DYNAMIC RESPONSE; SPACECRAFT CONFIGURATIONS; SOLAR ARRAYS; VIBRATION EFFECTS; SPACECRAFT ORBITS; SOLAR ENERGY; ELASTIC BENDING; TEMPERATURE EFFECTS; ANTENNA COMPONENTS; FRICTION; ENERGY DISSIPATION; SATELLITE ATTITUDE CONTROL; ORBITAL MECHANICS; APPENDAGES; ROTATION; MECHANICAL DRIVES...
The Rotational Speed of the Upper Atmosphere, Determined from Changes in Satellite Orbits
Upper-atmosphere Properties Derived from Discoverer Satellites
Author: Ronald Smelt
Publisher:
ISBN:
Category : Upper atmosphere
Languages : en
Pages : 200
Book Description
Publisher:
ISBN:
Category : Upper atmosphere
Languages : en
Pages : 200
Book Description
Variations in the Earth's Upper Atmosphere as Revealed by Satellite Drag
Author: Luigi Giuseppe Jacchia
Publisher:
ISBN:
Category : Atmosphere, Upper
Languages : en
Pages : 94
Book Description
Publisher:
ISBN:
Category : Atmosphere, Upper
Languages : en
Pages : 94
Book Description
Scale Height in the Upper Atmosphere, Derived from Changes in Satellite Orbits
Measurements of Upper-Atmosphere Rotational Speed from Changes in Satellite Orbits
Author: D. G. King-Hele
Publisher:
ISBN:
Category :
Languages : en
Pages : 18
Book Description
The rotation of the upper atmosphere subjects a satellite to an aerodynamic force normal to the orbit, which has the effect of slightly reducing the inclination of the orbit to the equator. The average rotational speed of the upper atmosphere at heights a little above that of perigee can be evaluated from the observed changes in orbital inclination. Since the change in inclination is small (less than 0.1 degree), the values generally have to be averaged over several months, and they can also be regarded as applying over latitudes up to about half the inclination, the effects being strongest at the equator. Recent results reviewed in the report confirm a previous finding that the upper atmosphere at heights of 200 to 350 km rotates on average faster than the Earth, and that the average rate of rotation increases with height from about 1.1 rev/day at 200 km to nearly 1.4 rev/day at 350 km. However, it appears that the rotation rate decreases above 350 km, to about 1.0 rev/day at 420 km and 0.7 rev/day at 500 km. (Author).
Publisher:
ISBN:
Category :
Languages : en
Pages : 18
Book Description
The rotation of the upper atmosphere subjects a satellite to an aerodynamic force normal to the orbit, which has the effect of slightly reducing the inclination of the orbit to the equator. The average rotational speed of the upper atmosphere at heights a little above that of perigee can be evaluated from the observed changes in orbital inclination. Since the change in inclination is small (less than 0.1 degree), the values generally have to be averaged over several months, and they can also be regarded as applying over latitudes up to about half the inclination, the effects being strongest at the equator. Recent results reviewed in the report confirm a previous finding that the upper atmosphere at heights of 200 to 350 km rotates on average faster than the Earth, and that the average rate of rotation increases with height from about 1.1 rev/day at 200 km to nearly 1.4 rev/day at 350 km. However, it appears that the rotation rate decreases above 350 km, to about 1.0 rev/day at 420 km and 0.7 rev/day at 500 km. (Author).