With their unique global perspective, observation satellites offer incomparable advantages to help us better understand, manage and protect the Earth’s precious environment.
They provide an instantaneous view of vast areas of the Earth’s surface – a single image taken by a geostationary meteorological satellite, with coverage of up to 200 million square kilometres, can show nearly half the planet. They can observe every corner of the Earth, for both global assessments as well as detailed views of specific locations. With their rapid, frequent revisit capability, they can monitor phenomena as they evolve, be they natural or man-made.
At the time of their launch by Ariane 4 the two ERS (European Remote Sensing) radar satellites, built by Airbus Defence and Space (Matra Marconi Space) were the most sophisticated Earth observation spacecraft ever developed and launched in Europe. ERS-1 was launched in 1991 on Flight 44, with ERS-2 following four years later on Flight 72. These highly successful ESA satellites collected a wealth of valuable data on the Earth’s land surfaces, oceans, and polar caps and have been called upon to monitor natural disasters such as severe flooding or earthquakes in remote parts of the world.
ERS-1 and ERS-2 paved the way for new interferometry missions such as Envisat, launched in February 2002 on Flight 145, the Ariane 5 heliosynchronous mission. Europe’s largest and most complex Earth observation satellite, built under Airbus Defence and Space’s prime contractorship, carries 10 instruments for helping scientists gain a better understanding of the effects of global warming, El Niño, climatic changes and the depletion of the ozone layer, as well as variations in ocean-levels, ice caps, vegetation and the composition of the atmosphere. Development and construction of the 8,200kg spacecraft took more than 10 years, and involved almost 100 companies in 14 countries. Envisat has built up a phenomenal gallery of images, one of the most dramatic of which is the picture of the break-up of the 200-metre-thick Larsen B ice shelf the Antarctic Peninsula, which Envisat was launched just in time to catch.
Just one of many stunning Envisat images – featuring the Galapagos islands. The image was obtained by combining three Advanced Synthetic Aperture Radar (ASAR) acquisitions taken over the same area between 2006 and 2009. (© ESA)
Ariane has launched all five of the Spot optical observation satellites, all developed and built by Airbus Defence and Space and its predecessor companies and exploited by the company’s subsidiary Spot Image, a global reference for geo-information services. The success of the Spot series dates back to its earliest days – Spot 1, launched in 1986 on Flight 15 (the last Ariane 1 mission) had been destined for a three-year lifetime, but actually served 18 active years, providing nearly three million images before being conscientiously de-orbited and disintegrated to better respect the space environment.
When Ariane 4 lofted the military reconnaissance satellite Helios I, primed by Airbus Defence and Space (then Matra Marconi), in 1995 on Flight 75, it launched not only a considerable advance in Europe’s ability to obtain military space observation data, but also a new dimension for European security, as the Helios programme was the first instance of genuine space system cooperation in the defence field between a number of European nations.