A ‘marathon’ to the moon and Mars

A Long March 5 rocket carrying China's Chang'e-5 lunar probe launches from the Wenchang Space Center on China's southern Hainan Island on Nov. 24, 2020, on a mission to bring back lunar rocks, the first attempt by any nation to retrieve samples from the moon in four decades. (STR/AFP/Getty Images/TNS)

THE United States and China are racing to return humans to the moon and construct bases at the lunar south pole, all in preparation for an historic mission to Mars. Here is a timeline estimate.

2024: Send a crew to orbit the moon