One of the major hurdles to sending humans to Mars is their pesky predilection for eating. The amount of food needed for astronauts during a months-long trip to Mars and back would weight too much to make such a mission feasible. The solution is for astronauts to take a sustainable habitat with them. That or keep sending rover emissaries that don't need food.
The state-run Chinese news agency Xinhua this week revealed that China's space program is working toward being able to grow food on hypothetical extraterrestrial bases in places such as the moon or on Mars.
According to the report, the Chinese Astronaut Research and Training Center (CARTC) has just completed a lab experiment that attempted to balance oxygen, carbon dioxide, and water production between plants and humans in a closed environment. Two participants (presumably not these guys) were sealed in a 300 cubic meter cabin designed to provide a sustainable supply of air, water, and food. During the experiment, the participants were able to pick from four different fresh vegetables for meals.
According to Deng Yibing, deputy director of CARTC, the experiment is unique in China and is part of the country's long-term goals for it's manned space program. It is China's third generation life support system, which Xinhua referred to as a "controlled ecological life support system" (CELSS).
Earlier this week, NASA announced it's plans for Mars exploration for the next seven years, which include a new Mars rover to be launched in 2020. Part of the focus during NASA's announcement was how the new rover design will be based on the current new Mars rover, Curiosity, to save money. Considering NASA's dwindling share of the U.S. budget in the past decade and the Chinese space program's huge resources, it's not inconceivable that China will send a human to Mars before NASA can realize President Obama's challenge to do so by the 2030s.