LUMPS of Beer cliff which were rocketed up to space more than a year ago for a scientific experiment are finally making their way back home. The tiny cubes of rock have been exposed to the vast vacuum of space while sitting in boxes, known as EUTEF (Europ

LUMPS of Beer cliff which were rocketed up to space more than a year ago for a scientific experiment are finally making their way back home.

The tiny cubes of rock have been exposed to the vast vacuum of space while sitting in boxes, known as EUTEF (European Technology Exposure Facility), attached to the orbiting Columbus International Space Station for a year-and-a-half.

But now astronauts from the space shuttle Discovery have retrieved them and the rocks are spending their last days in the final frontier.

The rocks are part of a European Space Agency exobiology experiment investigating how organisms and life might survive elsewhere in the Solar System.

Discovery is due to blast into Earth's atmosphere on Friday, September 11 and will land in Florida.

Once they have reached our planet, scientists will examine the rocks to try and find out if any of the microbes that normally live in Beer cliffs have survived the extreme conditions of space such as ultraviolet light, cosmic rays and acute temperature changes.

Charles Cockell, microbiology professor from the Open University, said: "Although Beer is not an extreme environment, the surface of the cliffs there are.

"The green photosynthetic microbes that live there are exposed to desiccation and ultraviolet radiation from the Sun and we know that they include novel extreme tolerant species.

"We launched small pieces of the cliffs into space to expose them to extreme conditions of space as part of a European Space Agency programme.

"We are interested in the microbes that can survive these conditions. They might be used in future space applications, such as life support systems for stations on the moon."

The rocks collected by Discovery astronauts are incorporated in a science package of nine experiments.

As well as exposing samples to the harsh conditions of space, the package is also designed to test materials, analyse the near Earth orbit environment and take pictures of our planet.