Europe’s first radar Earth observation satellite, ERS-1, was in orbit from July 1991 until March 2000, exceeding its planned lifetime by more than three times. Its successor, ERS-2, was launched in 1995. It, too, has now exceeded its nominal lifetime but remains in excellent condition.
Astrium was the prime contractor for both missions and delivered the platform and a number of the main instruments, including an active microwave radar instrument (AMI) which combines a Synthetic Aperture Radar (SAR) and a scatterometer measuring wind speed and direction. Radar satellites, as opposed to those based on optical observation technologies, can image the Earth’s surface in all weathers, day or night.
ERS-1 and ERS-2 paved the way for new interferometry missions such as Envisat, launched in February 2002 and the on-going TerraSAR, MicroSAR and Theos programmes.
