Space Antenna Handbook

Chapter 16

Space Antennas for Radio Astronomy

Paul F. Goldsmith

Jet Propulsion Laboratory, California Institute of Technology, USA

16.1 Introduction

This chapter discusses antennas used for radio astronomy observations carried out from spacecraft. The considerations for space radio astronomy antennas differ somewhat from those applied to satellite communications and remote sensing of the Earth. Radio astronomy observations from space cover an enormous range in frequency from below 1 MHz to over 1000 GHz. The upper frequency limit is certainly arbitrary as the terminology as well as the technology change gradually as one moves from the submillimeter to the far infrared. The critical antenna parameters also vary considerably depending on the type of observations to be carried out. This necessarily incomplete discussion includes four areas in which space observations have played a major role: cosmic microwave background observations, submillimeter/far-infrared astronomy, low-frequency radio astronomy, and space very long baseline interferometry. For each area, we discuss key aspects of antenna performance and give a summary of the space missions with some detailed information about the antennas that have been employed.

16.2 Overview of Radio Astronomy and the Role of Space Antennas

Radio astronomy deals with the collection and analysis of electromagnetic signals from celestial sources in what is quite imprecisely defined as the radio wavelength or frequency range. The first observations ...