The robotic reach to the Red Planet includes grabbing, bagging and then shipping Martian soil and rocks back to Earth. But bringing home the goods, Mars style, is neither easy nor cheap to do. In terms of engineering difficulty, some officials call it “Apollo without astronauts.” For years, NASA has wrestled with numerous cash and carry concepts to return chunks of the extraterrestrial terra firma, enough material so electron-microscope peering scientists can get a hands-on feel for Mars. Scrutiny of those bits and pieces may well reveal a message of life. Whether it