Requirements for tethered systems (clause 10) are intended to be adopted by spacecraft carrying tethers of greater length than 1 km. For scientific missions, shorter tethers can make these requirements applicable, depending on the whether a minimum spacecraft voltage is specified. Long wire antennas for electric field measurements about a spinning spacecraft do not represent a problem because:
• they are comparatively short (generally less than 100 m);
• they are deployed symmetrically about the spacecraft so result in little net charging;
• the spacecraft spin inhibits electrically induced oscillations in the wire.