European experiments are to be installed on Chinese satellites for the first time following an agreement between the European Space Agency (ESA) and the Chinese National Space Administration to develop a joint project known as 'Double Star'. Double Star will study the effects of the Sun on the Earth's environment, following the ESA's earlier Cluster mission. Ten instruments currently flying on the Cluster spacecraft will be included in the Double Star project, along with eight experiments by Chinese institutes. By conducting joint studies with Cluster and Double Star, it should be possible to increase the overall scientific return from both missions. 'This agreement marks a significant advance for international cooperation in the exploration and peaceful use of outer space,' said ESA director general, Antonio Rodatà. 'It is one of the most important landmarks in East-West scientific collaboration since ESA and the People's Republic of China first agreed to exchange scientific information more than 20 years ago.' ESA will contribute eight million euro to the project, which will be used for refurbishment and pre-integration of the European instruments, acquisition of data for four hours per day and the coordination of scientific operations.