From June, 5438 to October, 2004 10, then US President George W. Bush released the "New Space Exploration Plan", which included developing the next generation spacecraft, returning to the moon and even landing on Mars. From June, 5438 to February, 2006, NASA released the "Return to the Moon" program, which described the overall framework and objectives of American lunar exploration in 2 1 century. Its core goal is to establish a permanent base on the moon as a springboard to prepare for landing on Mars and even exploring more distant space. According to this plan, American astronauts may return to the moon for the first time in 2020, and the previous landings may be completed by four astronauts, who will stay on the surface of the moon for about 7 days. Subsequently, the United States will gradually build a lunar base, including power supply system, lunar rover assembly and astronaut residential area. The final permanent lunar base will ensure that astronauts can live on the moon for 180 days, which can prepare for manned exploration of Mars. There are three important aspects worthy of attention in the "Return to the Moon" program. One is the next-generation spacecraft "O 'Ryan" with the manned mission of "returning to the moon". At present, the spacecraft has entered a critical stage of development. According to the plan, O 'Ryan will fly to the International Space Station 20 14 years ago and carry out a manned mission to the moon in 2020. The second is the lunar lander. It is one of the key equipment for returning to the moon. According to NASA, this lander will be able to work in unmanned and manned modes, and it can land anywhere on the moon quickly and safely. The third is to establish a permanent base for the moon. This requires many unmanned explorations, such as surveying the surface area of the moon that is convenient for landing on the moon, sampling and testing the natural resources of the moon, and evaluating the technical risk of the future lander. Among them, the location of the lunar base has attracted much attention, and the South Pole and the North Pole of the Moon are two alternative locations.