Cluster rises from the ashes
With lift-off from Kazakhstan set for next summer, the European Space Agency's Cluster II mission is well on the way to a full recovery from the tragic loss of the first four Cluster spacecraft in 1996. Scientists from across Europe will gather in London on 22 September to plan the final details of this unique mission to explore near-Earth space.
London is a particularly suitable venue since the UK has played a major role in the revival of the Cluster II mission. Three of the eleven scientific instruments on each spacecraft have been provided by UK institutions, and UK industry has also made important contributions.
Members of the media are invited to a press briefing in which scientists and representatives of UK industry will tell the story of the remarkable drive which has enabled Cluster to rise from the ashes. Details of the briefing are listed below.
CLUSTER II PRESS BRIEFING.
Date: September 22nd 1999
Venue: Senior Common Room, Physics Department, level 8, The Blackett Laboratory, Imperial College of Science, Technology and Medicine, Prince Consort Road, London SW7.
10.30. Welcome - Dr Ian Corbett, PPARC Director of Science
10.35. Mission Status - Mr John Ellwood, European Space Agency.
10.45. Cluster II's Scientific Objectives
11.00. UK Industry's Role - Mike Rickett, Matra Marconi Space.
A buffet lunch for the media will be provided after the briefing.
Why Cluster II?
Cluster II is a rerun of the European Space Agency's ill-fated Cluster mission which was lost during the Ariane 5 launch failure on 4 June 1996. ESA member states agreed that the science to be expected from the mission was so important that it had to be revived.
Cluster II comprises four identical spacecraft which will fly in formation around the Earth. Each satellite carries 11 scientific instruments in order to investigate the behaviour of charged particles (electrons and ions), electric and magnetic fields. UK scientists are principal investigators on three of these experiments. Funding for the UK scientific participation has been provided by the Particle Physics and Astronomy Research Council (PPARC).
The mission will investigate the Sun-Earth connection by studying what happens when the supersonic solar wind streaming towards Earth slams into our planet's protective magnetic shield. By studying these events and processes in unprecedented detail, Cluster II will provide scientists with a new understanding of how the Sun affects our lives.
The four spacecraft are scheduled for launch next summer from Baikonur Cosmodrome in Kazakhstan. The timing of the launches is particularly fortunate since the Sun is expected to reach the peak of its 11-year cycle of activity in late 2000. The increased number of sunspots and solar flares is likely to have a significant impact on near-Earth space, resulting in Cluster II encountering large numbers of energetic particles streaming from the Sun.
The satellites will be carried into space in pairs by two Soyuz rockets, and will follow a highly eccentric, polar orbit which varies from 19,000 to 119,000 km above the Earth. This track will carry them across the various regions and boundaries of the Earth's magnetic shield - the magnetosphere - and into interplanetary space which is dominated by the electrically charged particles of the supersonic solar wind.
For much of the two-year mission lifetime, the spacecraft will fly in a tetrahedral (three-sided pyramid) formation. Their separation distance will vary from a few hundred kilometres to 20,000 km, according to the amount of detail scientists want to obtain about a particular region of near-Earth space.
TV media can obtain BETA CAM material on Cluster II from:
Charlotte Allen at PPARC press office (see above).
UK Principal Investigators are:
FLUXGATE MAGNETOMETER (FGM) EXPERIMENT:
PLASMA ELECTRON AND CURRENT EXPERIMENT (PEACE):
DIGITAL WAVE PRECESSOR (DWP) INSTRUMENT:
Engineering, Sheffield University, Mappin Street, Sheffield S1 3JD.
FURTHER INFORMATION ON THE CLUSTER II MISSION IS AVAILABLE FROM THE WORLDWIDE WEB AT: http://sci.esa.int/cluster
Peter Bond, RAS Press Officer (Space Science).
10 Harrier Close, Cranleigh,
Surrey, GU6 7BS, United Kingdom.
Phone: +44 (0)1483-268672
Fax: +44 (0)1483-274047