The space shuttle, Discovery, and its seven astronauts returned to Earth safely today, bringing a successful end to NASA's troubled return to human space flight two and a half years after the Columbia disaster.Discovery made its fiery re-entry into Earth's atmosphere and swooped over the Pacific Ocean before gliding to a smooth landing at 0812 hrs EDT (1742 hrs IST) at Edwards Air Force Base in California after a 14-day mission that included a stay at the International Space Station.Space Shuttle Discovery Commander Eileen Collins said the gut-wrenching 14-day voyage had been "fantastic', but that she and her crew were relieved to be back to Earth.