Later this month, a British-made lander known as the Beagle 2 is scheduled to be delivered to the European Space Agency's primary contractor for the Mars Express spacecraft.

The lander – named after the ship Charles Darwin sailed in to explore unchartered areas of the Earth in 1831 – will be integrated with the spacecraft in Toulouse, France, thus nearing the end of preparations for the summer launch of an exploratory mission to Mars.

The mission, whose goal is to search for sub-surface water from orbit and to deliver the lander to Mars, is expected to be launched in June and to land on Mars in December. It is timed to coincide with Mars' closest approach to Earth in 17 years, which takes place in August 2003.

The distance between Mars and Earth varies because they have elliptical orbits. By launching the mission during the closest approach, the spacecraft will take the shortest possible route, thereby costing less than a longer trip would.

Precursor to manned mission to Mars

The Mars Express is a precursor to later manned missions to Mars, which scientists say could happen in the next 15 to 25 years. Indeed, preparations for such a mission are already under way.

On Thursday, medical researchers in Berlin put out a call for volunteers to participate in a study that will seek to determine how the astronauts – who are expected to be under way for two years for the Mars mission – can counter the effects of long-term weightlessness.

Long-term exposure to weightlessness damages muscles and bones and the researchers are hoping to come up with ways to ensure that the astronauts don't break their legs once the get out of the spacecraft for the first Mars walk.

The study, conducted by doctors at the Free University of Berlin in conjunction with the European Space Agency, is scheduled to begin in February and will last for two months. During this time, some 20 volunteers will live under conditions that simulate that of the astronauts on the Mars mission. Namely, they will live in simulated weightlessness and will be allowed no contact with other people.

Destination: Mars

David Hall, director of science at the British National Space Centre in London, told BBC News Online that by 2025, Europe will likely have the expertise to send a human to Mars.

But the costs for such a mission are likely higher than Europe can afford on its own, thus the European Space Agency is eyeing collaborations with the United States, Japan, Russia and perhaps even China, according to the BBC.

Russian scientists announced this summer that they were planning to send people to Mars by 2015 – but noted that they needed international cooperation for the mission to succeed. In the works is a 440-day mission with six people, with a price tag of about $20 billion, according to the BBC.

The Russians last attempt to launch a spacecraft to Mars, in 1996, ended in failure after the spacecraft crashed into the Pacific Ocean.

Comet mission delayed

Failed missions are certainly on the minds of European space scientists following the December 11 mid-air explosion of an Ariane-5 rocket. This delayed the launch of the Rosetta spacecraft, which was set to be launched by an older version of this rocket launcher.

The Rosetta launch had been scheduled for January 12, but officials now say they will disclose a new launch date on January 11.

The Rosetta is supposed to make an eight-year trip to the comet Wirtanen The project has been 10 years in the making, and scientists are on edge as planetary conditions dictate that the launch must take place by early February in order to succeed.

Mars Express an international endeavor

The Mars work goes on, meanwhile, with contributions coming from around the world. The radar instrument for probing water depths is a joint enterprise between Italy and the Jet Propulsion Laboratory in California. The spacecraft includes a stereoscopic camera from Germany, a geological mapping device from France and an atmospheric sounder from Italy. And the landing craft is being built in the United Kingdom.

The Beagle 2 lander is expected to take photographs that will guide future explorations. Ist robotic arm will gather rock fragments to be analyzed for the existance of organic matter. The experiments aim to determine whether there is any evidence of past life on the planet.