Johann-Dietrich Woerner, head of German aerospace giant DLR, is to succeed Frenchman Jean-Jacques Dordain as next director-general of the European Space Agency, ESA announced on Thursday.

Woerner, 60, will start the four-year term on July 1, the agency said, quoting a decision by ESA's ruling body.

ESA traces its roots back 50 years with the foundation of two organisations aimed at beefing up European collaboration in space research and rocket launchers.

They were consolidated into a single organisation in 1975.

The agency today comprises 20 member states, a figure likely to rise to 22 with the expected admission of Estonia and Hungary. Canada has a seat on its governing body and takes part in some projects under a cooperation agreement.

Dordain, aged 68, was first appointed in 2003.

His tenure has seen one of the most successful periods in ESA's history.

Missions include the comet-chasing probe Rosetta, the Herschel and Planck orbital observatories, unmanned exploration of Mars and Venus, resupply of the International Space Station (ISS) by robot freighters and a string of Earth-observation satellites.