CONTENTS

ANNEX  1
Flexibility in the positioning of satellites
 1     Introduction
 2     Orbit efficiency and system considerations
 3     Potential problems associated with satellite re-positioning
        3.1     Service arc limitations
        3.2     Earth-station antennas
        3.3     Earth station repointing
                  3.3.1     General
                  3.3.2     Repointing of very small antennas
                  3.3.3     Repointing of 1-2 m antennas
                  3.3.4     Repointing of 2-5 m antennas
                  3.3.5     Multiple-beam earth station
                  3.3.6     Service disruption
        3.4     Coverage areas and satellite antennas
        3.5     Solar eclipse
        3.6     Propellant required for changing orbital location
        3.7     Control during relocation
        3.8     Other problems identified
 4     Second generation satellite considerations
 5     Conclusions
ANNEX  2
Fuel consumption as a function of drift rate and angular displacement for relocation of a spacecraft