Why we have to explore the space, including knowing and landing on the Moon and Mars? In case of academic research, there is no need for a reason. Knowledge is knowledge, human needs knowledge and pursue of knowledge is given on birth. Knowledge is endowed by the great nature, so we explore the great nature is so natural. If man do not have knowledge, it is no difference to animal. Why man is on the highest level of all creatures, because we have knowledge. Therefore, the greatest knowledge is in the universe, when we explore the universe, there is no need for a reason.
However, in case of pragmatism, we invest so much in exploration of the universe or the Moon and Mars, why we do not invest in other knowledge? Such as earth quake, hurricane, geothermal energy, hydrogen energy cars, wind energy, minerals of the earth. They are all of great nature. That is people may ask what is the practical usage of space industry?
There are a lot of usages in our daily life but we are not aware of, they are caused by space industry. After Neil Armstrong landed on the Moon, of course, he has to report to Huston Center first, and later on talk to the president of the United States. In the 1970s, it is a common occurrence of the president to talk to astronauts on the Moon, for there is a total of 6 Apollo flights. So made people have an idea of mobile phone. There is no telephone company on the Moon, no power plants, but Apollo crews still can talk to the president on phone, so why we cannot talk to others in a car, ship or train on earth with other phone owners?
Thus gave an idea of developing mobile phones. At first the control center in Huston talk to astronauts using their communication device, it is so common. But later on, when the crews on the Moon talk to the president, he was sitting in White House using a desktop phone to talk. So, it generated the idea of mobile phones and was successfully developed by the end of 1970s in cars only, and in 1980s developed to hand carry mobile.
Later on, developed into GPS system, at first was by hikers in the mountain, now can be used by every single car for guiding the route, and even for waiting the bus in stations and on Google Map can guide everyone in a strange city.
But one more important change is the Kamikaze of Japan by the end of World War II. Westerners were surprised to see the suicidal planes of Japan crashing into US warships. It is a non-humane deed, but to Japan, it is extreme patriotism. So, people are thinking of is there any method to shoot precisely at the target without using the Kamikaze planes. That is the GPS system developed by satellites in lower orbit of the earth.
In the 1990 Iraqi War, guided missile was first used in practical war and found it is so accurate and would not hurt the general citizens and only at designated targets, so the carpet bombing of World War II no longer needed. Satellite in lower orbit of the earth proved useful, not only for space exploration but also military usage on earth.
Mind that Space Exploration is one of the best methods to show the power of a nation in peaceful manner. Therefore, no matter developed or under developing countries are keen to join the race. Please be noted that Israel is just a small nation, but they also have a spacecraft having a hard landing on the Moon in April 2019, with a flag of “small country, big dreams” and crashed on the Moon. Now, only 2 countries have the power of decapitation operation, that is to kill the leader of other countries by special air force mission. That is US and Israel.