In very general terms, here’s what has to happen to get ATV-3 undocked:

  • ‘Wake up’: ATV avionics & on board flight control systems will be powered up
  • Demerging: Uncoupling of power & data connections
  • ISS transitions to ‘Free Drift’ mode – to avoid any movements/rotations that might interfere with ATV undocking
  • ATV Hooks opening – starting to release the vessel’s grasp on the ISS
  • ATV Undocking starts – push back of Europe’s cargo vessel by pressure springs.
  • ATV Departure manoeuvre – thruster burn to pull Edoardo Amaldi back & away from Station