The Prediction of Satellite Lifetimes
Abstract
Accurate prediction of the lifetimes of satellites decaying naturally under the action of air drag is one of the most difficult problems of orbital dynamics. Such estimates are of practical importance when a satellite perceived as 'dangerous' is about to decay. The time when the satellite finally plunges into the lower atmosphere is affected by a least 8 identifiable types of variation in upper-atmosphere density, by odd zonal harmonics in the gravitational field, and by possible changes in the mode of rotation of the satellite. Since 1958 we have made (and revised) lifetime estimates for all satellites, rockets and other major components (but not fragments) for use in the RAE Table of Satellites. More than 10000 such predictions have been made, nearly all being calculated from the current observed decay rate. This report summarizes methods used in the past and gives the results of new orbital theory developed to take better account of the effects of atmospheric oblateness and odd zonal harmonics in the geopotential. It also describes new approximate methods to allow for the effect of the solar-cycle and day-to-night variations in air density, and includes discussion of other sources of error. Separate sections give techniques to use when no observed values of decay rate are available. We give the graphical-analytical methods devised for two common types of high-eccentricity orbit - geosynchronous transfer orbits and Molniya-type orbits.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1987
- Accession Number
- ADA189710
Entities
People
- Desmond King-Hele
- Doreen M. Walker
Organizations
- Royal Aircraft Establishment