Technology CubeSat GomX-4B undergoing ‘degaussing’ – reducing the magnetic fields of its component parts by applying an opposite magnetic field to it – at ESA’s Mobile Coil Facility at its technical centre in the Netherlands in June 2017. Such a magnetic cleaning procedure is needed to optimise the performance of the ‘magnetotorquers’ the nanosatellite will use for attitude control, with electromagnets reacting to Earth’s magnetic field.