YOKOHAMA, Japan - The CHIKYU is studded with superlatives. Completed last year, the ship houses the world's biggest deep-sea drill, sports a high-tech floating laboratory and boasts a $500 million price tag. The Japanese boat has an ambitious agenda to match: uncover the secrets of climate change, find microbes that help explain the origin of life, and clarify the causes of earthquakes. The 210-yard ship underwent its first major test run in November, drilling deep into the ocean floor off northern Japan for specimens that scientists say can yield historical information on everything from volcano cycles to global warming. "The...