Wang Yue (1st R), a Chinese participant of the Mars-500 program, is welcomed by his colleagues, relatives and friends upon his arrival in Beijing, capital of China, Dec. 6, 2011. Chinese researcher Wang Yue, along with five other astronauts from different countries, has successfully finished Mars-500, the 520-day mission of living in a confined capsule that simulated a trip to Mars, on Nov. 4. [Xinhua/Wang Shen]