Munich

Leading European space scientists have urged international space agencies to coordinate their research missions to ensure that they complement, rather than duplicate, each other.

At a meeting of the European Space Agency's (ESA) top-level science advisory committee and its science programme committee in Naples last week, scientists said that, apart from the Mars International Coordination Programme, cooperation between space-science disciplines is not as well established as it should be.

The committees, representing the astronomy, planetary-science and fundamental physics communities, met to discuss the scientific priorities for the ESA over the next decade. They noted that the major missions of the three largest space agencies are becoming increasingly similar.

For example, within less than a year, each will have launched X-ray observatories. The US space agency NASA's Chandra was launched in July, the ESA's XMM will launch in December (see opposite) and Japan's Astro-E will launch early next year. All three are also planning missions to Mercury.

The ESA's executive will consider ways of coordinating between disciplines, possibly at the level of the agencies' scientific advisory committees, to ensure complementarity of approach.

At the meeting, the ESA's executive said that the agency's science directorate will announce the opportunity for two medium-sized, ‘flexible’ missions in the coming weeks.

The executive also said that the ESA's next large, ‘cornerstone’ mission will be decided next June. The choice is between a journey to Mercury, called Colombo, and an astrometry project called GAIA.

One of the two flexible missions, to be selected in a free competition next September, will probably be a contribution to the Next Generation Space Telescope, the NASA-led successor to the Hubble Space Telescope. Decisions about the second will be influenced by the choice of the next cornerstone mission, as the ESA aims for a balance between disciplines.

The science programme committee also approved the ESA's first technology mission, SMART-1, to be launched in November 2002. This will test electric-propulsion technologies for deep-space travel on a lunar mission. Small experiments will also fly on the mission, gathering X-ray and infrared spectroscopy data about the Moon's surface.