Experiment volunteers take 2nd 'walk on Mars'

Astronauts on a simulated flight to Mars made a second walk on a mock-up of the Red Planet's surface in Russia Friday, collecting soil samples for analysis.

Russian Alexander Smoleyevsky, who made the first of three planned sorties with Italy's Diego Urbina on Monday, was joined by China's Wang Yue this time.

Six volunteers "reached Mars" on Monday after spending eight months in a space capsule cut off from the world on the simulated flight.

Smoleyevsky, Wang and Urbina were deemed to have landed while Romain Charles from France and Russians Sukhrob Kamolov and Alexei Sitev remained "in orbit" in the main module.

Friday's walk in full space gear, which also included testing for magnetic anomalies, lasted for some 40 minutes on the sandy soil laid on the floor of a Moscow research centre.

Television pictures were relayed to Russia's real-life space control centre outside Moscow.

The third walk, by Smoleyevsky and Urbina, will take place Tuesday before all six -- three engineers, a doctor, a surgeon and a physicist -- are locked back in the capsule for the long "return flight."

Officially called Mars-500, the unprecedented experiment with the six volunteers, aged between 26 and 38, spending 520 days in isolation is to test how humans respond to the pressures of a there-and-back voyage to Mars.

Although not weightless, they are spending their time in tight quarters that prevent their bodies from getting their normal doses of exercise.

The mock-up space craft's living quarters measure just 20 metres (yards) long and less than four metres across, and special armchairs were set up on the "planet's surface" to help the men deal with the sudden stress.

The experiment is due to finish with a mock landing in November but Russia and the European Space Agency hope to be doing the trip for real by 2040.

(c) 2011 AFP