A possible generic problem with the thrusters on the four European Space Agency (ESA) Cluster satellites due to be launched by Starsem's Soyuz Fregat boosters in June and July has delayed the spacecraft's shipment to the Baikonur launch site in Khazakhstan.
The flight acceptance review discovered a problem apparently common to all four Clusters and to some other satellites built by DaimlerChrysler Aerospace's Dornier Satellitensysteme that are under assembly or have already been launched. Dornier Satellitensysteme and ESA decline to elaborate on the problem.
Each Cluster spacecraft, designed to study the interaction of solar wind and the Earth's magnetic field from 25,500 x 125,00km (15,800 x77,650 miles) elliptical orbits, has a single 90lb thrust (400N) engine and eight smaller thrusters fed by monomethyl hydrazine and mixed oxides of nitrogen.
The first Cluster satellites were lost in the failure of the initial Ariane 5 launch in June 1996.
Source: Flight International
