Scientific missions for earth orbital tether systems

Abstract

The current available in situ data on the physical characteristics of the 90-130 km environment depends on sounding rocket and maneuverable satellite systems for its collection. Such data are, of necessity, sporadic in both time and space. The development of tethered systems in Earth orbit will allow global, long-term observations of this environment for the first time. In addition, tethered systems will allow spacial gradiometry at altitudes from 130-400 km without the extensive celestial mechanics required to coordinate multiple satellite observing programs. This paper reviews some of the outstanding science questions for the altitude regime from 90-400 km which require the use of tethered observing systems for study. These questions involve the structure, temporal evolution, and composition of the uppermost atmosphere/lowermost ionosphere, the distribution of the high spatial frequency components of the magnetic and gravity fields, and the spatial gradients of the properties of the lowermost magnetosphere/uppermost ionosphere.