 an ambitious mission to search for life that has been buried beneath 3km of ice in an antarctic lake for hundreds of thousands of years begins in earnest this week.  a team of British scientists and engineers will start transporting the 70 tonnes of drilling equipment needed to penetrate the West antarctic Ice Sheet and sample the lake's water column and mud-covered floor. They hope to discover a "lost world" of microbial lifeforms that have survived in solitary isolation from the rest of the biosphere when Lake Ellsworth, which is nearly the size of Lake Windermere, froze over for the last time between 200,000 and one million years ago.  although buried beneath a cap of ice some 3.2km thick, the lake's water remains liquid because of the immense 