S-band helix antennas. This antenna became well renowned already at its introduction in the mid 70’s. Today, RUAG Space has delivered more than a hundred antennas. This antenna type has served numerous scientific and telecommuni-cation satel lites in their crucial Telemetry and Telecommand communication. Some variations of the basic theme have been developed includingcylindrical and conical helices with varying cover-age requirements. The antennas have excellent performance combined with low mass and tight manufacturing tolerances.