The European Space Agency (ESA), established in 1975, is an inter-governmental organisation dedicated to exploration of space with currently 17 member states. ESA has ambitious space plans that may be divided into three large categories. First, ESA will maintain its scientific and research projects (e.g. tests and developments of new propulsion systems), try to find ways to reduce costs for their rocket fleet while enhancing their capacities, honour its commitments regarding the ISS and engage in further space exploration like the Venus Express mission that was launched in late 2005. The second category has many parallels to NASA's plans and constitutes of astronomy-space missions such as the Planck Surveyor studying the cosmic microwave background (2008), the Herschel space observatory (2008), Corot that will be a milestone in the search for extrasolar planets and is due to launch in 2007.