N° 48–1995: ISO, ESA's explorer of the Unknown

Some burning questions left open in many fields of astrophysics, from nearby planets to the most distant quasars, taking in star formation, the dark matter of the universe and superluminous galaxies should find clues.

The 5,3m high satellite will be commanded into its 24h eccentric orbit by ESA's space operations centre in Darmstadt (Germany). In its final orbit the spacecraft will pass as close as 1000 km to the Earth and go as far as 70,500 km. After the first signal from the satellite has been received, 45 minutes after the launch, the spacecraft controllers will switch on the systems and instruments on board over the next 72 hours before handing the control of the satellite over to Science Control Center located at ESA's Villafranca ground station near Madrid.

A fully international team of 100 or so operations engineers and scientists will monitor and control the satellite from some 18 months of operational life time. Reflecting the project's international dimension, American and Japanese scientists will be co-located at its operations center and the NASA station at Goldstone, California, will relay communications when the satellite is out of Europe's ground station view. Full coverage will be provided with real-time links, making it possible to carry out observations for 16hrs per day when the observatory is outside the radiation belts.

The building of the satellite has been an engineering challenge to the European Space industry and "will be the culmination of twelve years of intensive effort to build the most powerful and precise infrared space observatory to date", Prof. Bonnet, Director of ESA's Science Programme, said.

The media are kindly invited to participate in the launch event in ESA's European --Space Operations Centre (ESOC) where the main press information center will be located. The launch can also be followed in other establishments where the respective PR officers can be contacted.