There were many steps that were taken before the Apollo missions began. For one, there was the Gemini missions. These were meant to prove that life could be sustained in space. After they worked, and this was proven, scientists then moved to their next step. The next step was proving that a person could live in space. They took baby steps by starting with a few days and moving up to two weeks. After this was proven to be true, then scientists developed the Apollo program. This entailed proving that people could work in space and on the moon. These missions were successful. Even though Apollo 13 experienced troubles, this also helped scientists deal with and learn from these errors.
Ultimately, scientists wanted