An experimental pair of miniature CubeSats monitoring water quality across Spain and Portugal employ wing-like deployable flaps and solar panels to perform manoeuvres down or sideways on a fuel-free basis, moving against the scarce air molecules found at the very top of the atmosphere.

The ANSER satellites from INTA in Spain perform fuel-free orbital manoeuvring relative to each other, based on deployable flaps and solar arrays which can increase the surface area of each CubeSat more than 21-fold. Depending on their attitude, the satellite can either be dragged lower by atmospheric friction or else moved sideways, out of plane – like a sailor tacking the sails of their yacht. So far the satellites have been descending from an approximately 570 km altitude to reach their nominal 500 km altitude orbit.

This clip is made from real attitude data downloaded from ANSER’s Follower 2 CubeSat, reproducing the actual actions it performed along one complete orbit, reproduced here at 50:1 speed.

The satellites seen here are visualised using VTS (Visualization Tool for Space data) software which is licenced freeware owned by French space agency CNES and developed by the Spacebel company in Belgium.