Three Chinese astronauts stranded at their nation's space station after their spacecraft was apparently hit by space debris departed for home Friday using the craft that had brought a replacement crew, China's space agency said.The astronauts were on a six-month rotation at the space station and originally scheduled to return Nov. 5, four days after the new crew arrived.Their return was delayed for more than a week. China's Manned Space Engineering Office said there were minor cracks in a window of the return capsule of the Shenzhou-20 spacecraft, most likely caused by impact from space debris.There are millions of pieces...