After nine months in orbit, China's mysterious space plane has landed for the second time, making the nation one of the few entities to successfully launch and recover a reusable spacecraft. "The complete success of this experiment marks a significant breakthrough in our country's research on reusable spacecraft technology," Xinhua, a Chinese state media agency, reported earlier this month. However, the Chinese government has released very little additional information about the craft; the details of its design, capabilities and performance remain hazy. Experts think the Chinese plane is likely similar to the Boeing X-37B, a U.S. space plane that debuted...