The Antenna System of the Helios Solar Probe

Abstract

For the Helios solar probe a complete antenna system was developed and manufactured which is suitable for the various mission requirements, as near earth phase varying aspect angles, close sun flyby and maximum distance of 3,0. 10⁸ km with spin axis orientation perpendicular to the ecliptic. The near earth phase requirements were covered by a low gain antenna system with an isotropic radiation pattern. After the rough orientation of the spin axis a medium gain antenna with an omnidirectional radiation pattern will be used. After final orientation of the spin axis perpendicular to the ecliptic plane a high gain antenna with a despun wire grid reflector will be used for the telemetry link. By switching devices and/or hardwire connections the antenna systems are partly redundant in order to get the required high reliability. The maximum operating temperature range of the antenna system is + 200° to - 200°C.