SINGAPORE — With the U.S. government pledging to resume manned missions to the Moon, and eventually send a mission to Mars, Cold War-style competition over space exploration is re-emerging — between China and the U.S. this time. China hopes to make its first manned lunar landing within 15 years, around six decades after the last American walked on the moon in 1972. But China is not as far behind as those dates suggest. It hopes to make the first-ever landing on the dark side of the Moon by the end of 2018. This feat eluded the U.S. and Soviet Union during the heyday of their Space Race from the late 1950s to the mid-1970s. Other Asian counties, notably Japan and India, have their own space programs. But China appears to be leading the way.