Double Star update for European scientists
27 September 2001Important steps towards the realisation of a unique East-West collaboration were taken during a recent visit to Beijing by European scientists and engineers. During the week of 10-14 September, representatives from ESA and 10 European instrument teams took the opportunity to renew acquaintance with engineers working on the Double Star mission.
East meets West on 'Double Star', a joint mission to explore Earth's magnetic field This visit was the first since ESA and the Chinese National Space Administration (CNSA) signed a joint agreement to develop the Double Star project. The 16-strong European group visited the Centre for Space Science and Applied Research of the Chinese Academy of Sciences (CSSAR) for an update on the Double Star mission and participated in detailed discussions about European participation in this exciting China-ESA cooperative programme.
The visitors also attended the first meeting of the Double Star Science Working Committee, where they were introduced to many of the Chinese scientists who will be working on the mission. Among those visiting China for the first time was Dr Harald Michalik from the University of Braunschweig, who has been appointed principal investigator for the Energetic Particle Spectrometer instrument after the recent death of Dr Berend Wilken.
Much of the time was spent on discussions concerning the technical interfaces between the European-built instruments and the two Chinese spacecraft to which they will be mated.
It was agreed that initial interface tests on the engineering models of the European instruments would take place next April.
"The Chinese spacecraft simulator will be brought to Europe for these tests," explained ESA's Double Star project scientist, Philippe Escoubet. "They will verify that the instruments and the spacecraft are compatible."
A number of minor changes to the original Double Star mission scenario were also announced. The target date for the launch of the 'equatorial' spacecraft (DSP-1) from Xichang, located in the south of Sichuan province, has now been moved to June 2003, followed six months later by the launch of the 'polar' spacecraft (DSP-2) from Taiyuan (in the Shanxi province, to the west of Beijing).
It has also been agreed that only one telemetry mode will be used, instead of the two modes ('normal' and 'burst') employed with ESA's Cluster spacecraft.
"By using only the 'normal' mode, the operations will be simplified considerably," said Dr Escoubet. "Although we will download less data per hour, this change will enable us to receive data over most of the orbit."
Double Star will follow in the footsteps of ESA's groundbreaking Cluster mission by studying the effects of the Sun on the Earth's environment.
A key aspect of ESA's participation in the Double Star project is the inclusion of 10 instruments that are identical to those currently flying on the four Cluster spacecraft. A further eight experiments will be provided by Chinese institutes. Conducting joint studies with similar instruments on Cluster and Double Star should increase the overall scientific return from both missions.
Scientists hope that all six satellites will be operational at the same time, so that it will be possible to coordinate the data from Cluster and Double Star.