Airbus has delivered the ACLS (Advanced Closed Loop System), an advanced life support system to purify air and produce oxygen for the International Space Station (ISS). The system also produces water, more or less as a by-product of the technology. ACLS was developed by Airbus for the European Space Agency (ESA) and is set to be used as a technology demonstrator on the ISS from summer 2018. The ACLS extracts a portion of the carbon dioxide in the cabin atmosphere and, using hydrogen obtained from splitting water molecules, converts it to methane and water in what is known as the Sabatier process. Oxygen is then produced from this water using electrolysis. This increases overall system efficiency and reduces the need for supplies from Earth.