The Swiss space technology company, Contraves Space, is hoping for a successful launch of two satellites from Baikonur cosmodrome in Kazakhstan on Wednesday in an ambitious mission of the European Space Agency.
Contraves Space of Zurich has developed, manufactured and tested the satellite structures that are key elements in the second part of the Cluster mission. The structure in each satellite supports 11 scientific instruments, liquid fuel for orbital manoeuvres, energy sources and other vital equipment.
The two satellites, affectionately named Rumba and Tango, will be launched by a Soyuz rocket and are set to join two other satellites in space successfully launched on July 16 (Salsa and Samba).
They will be taking part in a scientific programme aimed at researching the interaction between the Sun and the Earth.
If all goes according to plan, the four satellites will circle the Earth in an elliptical, polar orbit, at distances of between 25,000 and 125,000 kilometres.
"The satellite structure is critical in that it has to hold and support all the payloads during the launch and the mission, even when there is zero gravity. The structure itself comes under extreme exposure during launch when it is vibrated and accelerated," Umberto Somaini, chief executive officer of Contraves Space, told swissinfo.
Parts of the structure had to be manufactured under extreme tolerance levels. "There are areas where the tolerances are very tight. We're talking about 100th of a millimetre or even less," he added.
The mission is very much in the spotlight following a failed first attempt in June 1996, when four Cluster satellites were lost when the Ariane 5 rocket exploded just seconds after take-off.
Costs have been trimmed by 30 per cent since then, which partly explains the use of a Soyuz rocket for this latest attempt.
The European Space Agency says that four satellites in fleet formation should provide exact research of great importance. "The interactions between the solar wind and the magnetosphere - which protects the earth against solar winds - influence our own living environment and the Earth's climate as well," it argues.
The most spectacular phenomena resulting from this interplay are the polar lights that appear at the Earth's north and south poles.
Contraves Space is perhaps best known for its production of more than 130 payload fairings (the top part of a rocket, which protects the payload, usually a satellite) for the Ariane space programme.
However, it also produces mechanisms, for example in the Hubble Space Telescope, as well as scientific instruments and optical satellite communication equipment.
by Robert Brookes
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