Mars the target in space-race revival

CA new space race between the US and Russia is in the offing - but this time the object is to reach Mars, rather than the moon, and bring back a sample from its surface.

The US space agency, Nasa, yesterday unveiled detailed plans of the two spacecraft that it will launch in the next six weeks, to land on our closest planetary neighbour next year. But Russia also has advanced plans for a space mission to the planet, with an almost identical timetable for arrival. However, it has had to overcome serious financial problems - and has sought funding from Germany, France, the UK and US, and eastern European countries.

None of the missions, though, will bring back samples: each is a one- way trip. Return trips are not planned until 2005 at the earliest, while the prohibitive cost of sending a crewed mission - which would run into billions of pounds - means it is not even tentatively planned before 2010. The two-year round trip would be psychologically exhausting; the US astronaut Shannon Lucid was worn down by her unplanned 188-day stay on the Mir space station after shuttle problems extended her mission.

The announcement by Nasa aims to build on the excitement generated by the announcement from a team of US scientists that they had found evidence for past life on Mars in a meteorite. The findings have not been confirmed, but they boosted Nasa's profile when its budget was under attack, and impelled President Bill Clinton to announce substantial backing for the agency's planned space missions.

The first of the Nasa spacecraft, the $200m Mars Global Surveyor, is due to be launched on 6 November and the other, the $150m Mars Pathfinder, on 2 December. It would actually be Pathfinder which should arrive first - on 4 July 1997. It will consist of a stationary lander and a six-wheeled surface rover, intended to be controlled from Earth with a time delay of between six and 41 minutes between order and response.It will also carry out atmospheric tests.

Previous tests on Mars, by the Viking lander in the 1970s, showed no signs of life.

The Global Surveyor is due to arrive in orbit around Mars in September 1997, and begin putting together high-resolution maps of the surface, and of the weather and climate of the planet in the following March.

Russia's answer to the American announcement is its Mars 96 spacecraft - the first deep-space mission since the fall of the Soviet Union. Due for launch next month, the $450m project will have both an orbiting craft and two landing craft, both unmanned.

They will shoot darts under the surface to investigate the soil chemistry. It will also investigate the atmosphere, mineral deposits, seismic activity and magnetic fields.

The Soviet Union's last foray to Mars ended in failure, when technical failures on the unmanned craft meant contact was lost with the Phobos 1 and Phobos 2 missions in September 1988 and March 1989, just as they were approaching orbit.

Japan is also planning to send probes to Mars in 1998.