The Dynamics of a Rigid Body in the Space Plasma.
Abstract
The forces resulting from the passage of a conducting body through a partially ionized plasma are reviewed, with emphasis on large space structures. The forces include drag and torque from a number of independent mechanisms, including collisions with neutral and charged particles, solar radiation pressure, and interaction with the earth's magnetic field. The desirable economic lifetime of tens of years for a large space structure implies an orbital altitude of at least 1000 km, and more probably a geosynchronous orbit (6.6 R sub e). Drag forces are, therefore, unimportant, except during assembly in low earth orbit and when they generate torque because of a special structure or attitude geometry. For large, long structures with dimensions on the order of kilometers and mass on the order of 10 to the sixth power kg or more, the gravity-gradient-induced torque dominates all others even at geosynchronous-orbit altitudes. The magnitudes of the various forces are calculated for a non-rotating structure, 2 km long and 10 m wide, at altitudes between 250 km and 36,000 km (6.6 R sub e) above the earth. A short appendix lists additional mechanisms that act when an orbiting body has rotational as well as translational motion. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 28, 1979
- Accession Number
- ADA084806
Entities
People
- Peter J. L. Wildman
Organizations
- Air Force Research Laboratory