Method for electric solar wind sail tether production

We present a method to produce tether for the electric solar wind sail (E-sail) by bonding 25µm aluminium wires to a 50µmwire using an industrial semiautomatic ultrasonic wire bonder. We have used this method to create a 1.4 meter long two-wire tether structure with more than 100 wire-to-wire bonds. We tested 38 wire-to-wire bonds by destructive pull test and showed that they meet the 5g pull strength requirement of electric sail.