NBC News writes that with the current U.S.-led International Space Station expected to retire in 2024, China could be the only nation left with a permanent presence in space. China is "on the rise and the U.S. is in very real danger of falling behind in the future," warned Leroy Chiao, a former NASA astronaut and veteran of four space flights, one of which included commanding the International Space Station...Beijing is pouring money into funding the nation's ambitions — which include being the first to explore the dark side of the moon and sending a probe to Mars in 2020, the latter in direct challenge to U.S. and European space agencies...According to 2013 estimates by the Organization for Economic Cooperation and Development, China was the second-largest spender in space with annual budget of $13 billion — but still well behind the $40-billion U.S. space budget...Despite being decades behind the U.S. space program, China is clearly catching up and using what Chinese experts call the "latecomer's advantage" — exploiting the latest technologies to leapfrog space advancements.