The Automated Transfer Vehicle (ATV) is a ‘space truck’ – an unmanned, completely automated supply ship designed to carry supplies to the International Space Station (ISS). It is a major part of Europe’s contribution to the ISS programme.
Once in space, the ATV can be ‘parked’ while waiting for exactly the right moment for docking. This allows other mission objectives to be undertaken even after the launch of an ATV.
At a distance of 250 metres from the Station, the ATV system switches to guidance, navigation and control (GNC) mode which uses optical sensors, firing laser lights at reflectors mounted on the ISS’ Zvezda module that guide it to its final destination. After authorisation by the control centre, the ATV makes its approach to 12 metres and covers the last few metres to the ISS docking port at a relative maximum speed of 10 centimetres per second. The ATV’s extended docking probe has a diameter of about 15 centimetres and is captured by Zvezda’s docking port.
For the moment, it is more cost-effective for each ATV to be used only once and burn up upon re-entry to the Earth’s atmosphere.