Comparative analysis of selected radiation effects in Medium Earth Orbits
By: Jennifer A. Bolin
Contributors: Naval Postgraduate School (U.S.) 
Publisher: Naval Postgraduate School; Available from National Technical Information Service
Published: 1997
Place of publication: Monterey, Calif; Springfield, Va
Language: eng
Number of pages: 141
Description: Satellite design is well developed for the common Low Earth Orbit (LEO) and Geosynchronous Orbit (GEO)      and Highly Elliptical Orbits (HEO), i.e., Molniya, cases; Medium Earth Orbit (MEO) satellite design is a      relatively new venture. MEO is roughly defined as being altitudes above LEO and below GEO. A primary      concern, and a major reason for the delay in exploiting the MEO altitudes, has been the expected radiation      environment and corresponding satellite degradation anticipated to occur at MEO altitudes. The presence of the      Van Allen belts, a major source of radiation, along with the suitability of GEO and LEO orbits, has      conventionally discouraged satellite placement in MEO. As conventional Earth orbits become increasingly      crowded, MEO will become further populated. This thesis investigates the major sources of radiation      (geomagnetically trapped particles, solar particle events and galactic cosmic radiation) with respect to specific      Naval Research Laboratory (NRL) designated MEO (altitudes between 3,000 nautical miles (nmi) and 9,000      nmi; inclination angle of 15 degrees). The contribution of each of these components to the total radiation      experienced in MEO and the effects of the expected radiation on a representative spacecraft are analyzed in      comparison to a baseline LEO orbit of 400 nmi and 70 degrees inclination. Dose depth curves are calculated      for several configurations, and show that weight gains from necessary expected shielding are not extreme. The      radiation effects considered include proton displacement dose and solar cell degradation.
Notes: "December 1997."

Thesis advisor(s): Vicente Garcia, Brij Agrawal.

Thesis (M.S. in Astronautical Engineering) Naval Postgraduate School, December 1997.

Includes bibliographical references (p. 95-99)

Approved for public release; distribution unlimited.

Also available online.

Mode of access: World Wide Web.

System requirements: Adobe Acrobat reader.

US Navy (USN) author.

dk/dk cc:9116 05/08/98.