By Helen Briggs
BBC News science reporter, Berlin
Ministers from 17 European nations are meeting in Berlin to map out Europe's space activities over the coming years.
Esa boss Jean-Jacques Dordain must keep all members happy
The European Space Agency is seeking 8.8bn euros over three to five years to continue its existing space science programme and to start new ventures.
Key proposals include a Mars mission and a system to improve environmental and security monitoring from space.
The talks are regarded as pivotal to the future of Europe's space industry amid shrinking commercial markets.
The Esa council at Ministerial Level gathers every three to four years to reach key decisions on European space policy.
Some 27 ministers are attending the two-day talks in Berlin, which opened on Monday.
ESA SUBSCRIPTIONS 2005
Esa is made up of 18 member states (17 European countries and Canada)
The total requested budget is 8.8bn euros (£5.9bn)
3.1bn euros (£2.1bn) goes to the mandatory science programme
A further 5.7bn euros (£3.8bn) is needed to continue optional programmes and start new ventures
European Space Agency (Esa) spokesperson, Franco Bonacina, said the ministers would set the course for the future of the agency over the next three to five years.
"The success of Esa today is based on decisions which were taken 10 years ago," he said.
"Now it is time to start opening doors to set the course for new programmes."
Key proposals being discussed in Berlin include:
- The next phase of a programme to launch a series of satellites to monitor the health of the Earth, including building Cryosat 2, which would replace the ice-monitoring probe lost on launch in October.
- Implementing the GMES (Global Monitoring for Environment and Security) programme to improve environmental monitoring and policy making in Europe.
- Proposals to join forces with Russia on its new spaceship, the Clipper, which will eventually replace the Soyuz capsule.
- Work to define programmes that would lead to European cooperation on possible human missions to the Moon and Mars.
- Starting work on the proposed ExoMars mission to launch a lander to the Red Planet in 2011.
The first proposed mission under Europe's so-called Aurora programme is to land a robotic probe on Mars.
ExoMars would include a lander, rover and deep-drilling system that would explore for possible biology on our near neighbour and pave the way for a sample return mission.
"It's our entry ticket to prepare ourselves for landing, separation, rovering on Mars and in the future bringing back samples in a Mars sample return mission done with the Americans," said Mr Bonacina.
"But the ExoMars mission, that's to be made in Europe, is one of the big first steps into the future of space exploration for Esa."
WHAT IS THE GMES PROJECT?
A joint initiative of the European Union and Esa
Pulls together all Earth-monitoring data whether collected in space or not
Will use existing and newly commissioned spacecraft
Crucial to the understanding of how our climate is changing
Important for disaster monitoring - earthquakes, floods, eruptions, etc
An enforcement tool for EU policies: fishing quotas, etc
The European component of a global project known as Geoss
Another important issue is the flagship GMES (Global Monitoring for Environment and Security) project.
It has been the subject of intense lobbying in the UK, amid concerns that money allocated by the UK government may fall far short of industry expectations.
The status of launcher programmes funded by Esa, such as the Ariane-5 rocket and the newly developed Vega rocket, due to fly in 2007, may also split Esa's members.
Ministers will be asked to sign a resolution that would force member states to use a European launcher for non-commercial projects.
Analysts believe this could be a major sticking point, particularly among countries that make only a small contribution to Esa's launcher budget.