ERS-1: Continuing success story

European Remote Sensing satellite, ERS-1, launched 17 July 1991, was ESA's first Earth Observation satellite; it carried a comprehensive payload including an imaging Synthetic Aperture Radar (SAR), a radar altimeter and other powerful instruments to measure ocean surface temperature and winds at sea. ERS-2, which overlapped with ERS-1, was launched in 1995 with an additional sensor for atmospheric ozone research.

At their time of launch the two ERS satellites were the most sophisticated Earth observation spacecraft ever developed and launched in Europe. These highly successful ESA satellites have 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.

Both ERS satellites were built with a core payload of two specialised radars and an infrared imaging sensor. The two spacecraft were designed as identical twins with one important difference – ERS-2 included an extra instrument designed to monitor ozone levels in the atmosphere.

Shortly after the launch of ERS-2 in 1995 ESA decided to link the two spacecraft in the first ever ‘tandem’ mission which lasted for nine months. During this time the increased frequency and level of data available to scientists offered a unique opportunity to observe changes over a very short space of time, as both satellites orbited Earth only 24 hours apart.

In March 2000 a computer and gyro control failure led to the ERS-1 satellite finally ending its operations, far exceeding its planned lifetime. ERS-2 is expected to continue operating for several more years.

ERS-1 was controlled from ESOC, Darmstadt, Germany.
More information: ERS-1 and -2

Note: hi-res PDF download file is very large! Please be patient while file is transferred.