In 22nd century, a huge number of earth's citizens will settle on the moon. This would be possible due to the invention of international space shuttle that will be rapid, efficient, safe and affordable. It is also projected that dozens of permanent colonies will be established on the moon. Most of the colonies will be on the southern region of the moon due to the greater access to water. The residents of these colonies will consist mainly of scientists and explorers. Scientists during that era will also develop a form of artificial gravity that would make the moon suitable for living and have humans fully adapt to the gravity of the moon. Tourism will become a booming industry, as thousands of tourists will be arriving on the surface of the moon. Guided tours will include sites such as Apollo's landing and its mountain peaks as some of the popular destinations. Many tasks will also be handled by robots on the moon which will give its inhabitants more time to spend with their families.