Speech, science and spying
Over the last 40 years, satellites have become increasingly powerful and able to perform many different roles.
Most of the spacecraft launched by Europe’s Ariane-5 rocket are used for telecommunications – TV, digital radio, internet, video and telephone. They are usually owned by large international companies.
Most other spacecraft are owned by governments and space agencies such as ESA. Many of these are used for scientific research.
Over the last 25 years, ESA spacecraft have flown past comet Halley, gone into orbit around the Moon, Venus and Mars, and explored the distant Universe. In 2005, the Huygens probe landed on Saturn’s moon, Titan. In 2014, Rosetta will become the first spacecraft to orbit a comet and land a probe on its surface.
SOHO and four Cluster spacecraft have shown how the Sun works and how it affects our planet. The ERS satellites and Envisat have studied every aspect of the Earth, from ice caps and oceans to the ozone layer and land use.
A new series of Earth Explorer missions was introduced in 2009. Satellites such as GOCE, SMOS and Cryosat will improve our understanding of planet Earth and how human activity affects the natural world. A family of Sentinel satellites will soon be launched to study the land and oceans in great detail.