ESA Science & Technology - <FONT size=1>ESA PR 10-2003 </FONT> ESA chairs the International Living With a Star programme

The Sun is a variable star. The amount of radiation it releases changes constantly, especially at wavelengths that we cannot see, such as ultraviolet. It also releases a stormy 'wind' of particles known as the solar wind that buffets the Earth's magnetic field. Sudden changes in the solar wind can disable communications satellites, disrupt power stations on Earth, and affect passengers in high-flying aircraft. Slow variation in the solar output and even in the solar wind could contribute to climatic changes. Knowing more about these phenomena is therefore very important in different and sometimes unexpected ways.

There will be various ILWS missions launches over an approximately ten-year period, starting in 2003. Pooling the resources of the largest fleet of spacecraft in history, the ILWS programme will provide a first global view of the Sun-Earth interaction and lead to a real understanding of it. It will look at the Sun's effects on other planets also.

ESA's missions form a vital part of ILWS. SOHO and Cluster are leading the way. In 2003, in collaboration with China, a space mission called Double Star will be launched to complement Cluster. In a decade's time, ESA's Solar Orbiter will be the centre of interest. It will go closer to the Sun than any solar mission ever before. In between, ESA will assist in exploiting other agency's missions to the full; it is also currently negotiating to provide ground stations for Japan's Solar-B mission (launch 2005), and is considering the part it may play in NASA's STEREO (launch 2005), and NASA's Solar Dynamics Orbiter (launch 2007).

In addition, ESA's missions to the other terrestrial planets, Mars Express (launching 2003), Venus Express (launching 2005), and the mission to Mercury, BepiColombo (launching 2011/2012), will carry experiments that look at solar-wind interactions with their respective planets. Hermann Opgenoorth, ESA's newly appointed Division Head for Solar and Solar-Terrestrial Missions, is chairing the ILWS steering committee for the first two years. "There is a clear need to study the Sun and its relations to the Earth" he says, "and it is too big a job for a single space agency to cope with."

Notes to editors

The new International Living With a Star (ILWS) programme builds upon a previous international framework between Europe, Japan, Russia (formerly the Soviet Union), and the United States to study the Sun and its effects on Earth. That framework was the International Solar Terrestrial Physics (ISTP) programme. The SOHO and Cluster missions were part of ESA's contribution. For ILWS, the Canadian Space Agency has also joined the collaboration.

A 'kick-off' meeting between the space agencies involved in ILWS was held on 4-6 September 2002 in Washington DC, United States. An international steering committee comprised of representatives from those agencies will now supervise the programme. The committee comprises five space agencies: the National Aeronautics and Space Administration (NASA), the European Space Agency (ESA), Japan's Institute for Space and Astronautical Science (ISAS), the Russian Aviation and Space Agency (RASA), and the Canadian Space Agency (CSA).

There will be an ILWS Working Group to coordinate special projects. More than 20 space agencies have announced their participation in the first Working Group meeting, scheduled to take place in Nice, France on 14-15 April 2003. Contributions from the various space agencies include missions, payloads, subsystems, launch or tracking services, rockets, balloons, and open access to data sources.

For more information, please contact:

ESA Communication Department
Media Relations Office
Paris, France
Tel: +33 (0)1 5369 7155
Fax: +33 (0)1 5369 7690

Dr Hermann Opgenoorth
ESA - Head of Solar and Solar-Terrestrial Missions
Chairman ILWS Steering Committee
Tel: +46 (0)1 8471 5912
E-mail: opgirfu.se