ERS 1/2 tandem mission

Towards the end of 1993 it was becoming clear that ERS-1 was still in very good condition technically and operationally, even though it was coming to the end of its original lifespan. ESA saw the advantage, in terms of both scientific research and technological achievement in overlapping the work of ERS-2 with the remaining few months of life of ERS-1 by flying the two satellites together in a tandem mission.

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 twenty-four hours apart.

During 1999 the ERS-1 satellite finally ran out of fuel far exceeding its planned lifetime. ERS-2 is expected to continue operating for several more years.