The challenges facing Elon Musk and NASA in sending humans to Mars

President Donald Trump and Elon Musk, the world's richest man, want to make living on Mars a reality. Musk has said that his company, SpaceX, can get humans to Mars as early as 2029. Meanwhile, NASA officials have said that sending humans to Mars even by 2040 would be an "audacious" goal. China also has ambitions, with the country planning to establish an autonomous Mars research station by 2038. In Musk's view, going to Mars is tantamount to preserving humanity and escaping the ever-growing threats to Earth, including natural disasters and warfare. For scientists, Mars offers possible answers to questions such as the prevalence and diversity of life in the universe. "The early Earth and Mars were twins. They were both rocky planets with liquid water, CO2 dominated atmospheres," says Robert Zubrin, president of The Mars Society, a nonprofit. "So if the theory is correct that life originates naturally from chemistry, wherever the right physical and chemical conditions, then it should ... Read full article.