CONTENTS

1.���� Background � propagation effects
2.���� Technical and operational considerations
������� 2.1���� Mission frequency support requirements
����������������� 2.1.1���� Telecommand and maintenance telemetering
����������������� 2.1.2���� Mission telemetry
����������������� 2.1.3���� Tracking
������� 2.2���� Equipment factors
3.���� Link performance
������� 3.1���� Calculation of link performance as a function of frequency
������� 3.2���� Application to near-Earth space research missions
4.���� Discussion and conclusions