There were key problems that needed to be overcome in order for NASA to be able to land men on the moon and return them back. This problems include:
1. Takeoff : Generating enough force to escape Earth's gravity requires enormous energy.
2. Propulsion: Enough available fuel to return to Earth was crucial in order to take off.
3. Artificial Environment: Creating an artificial life support system for the crew of the ship. This must supply oxygen, filter out surplus carbon dioxide, provide heating, radiation shielding and a perfect seal in order to protect the occupants from the cold vacuum of space.
4. Provisions: Enough supplies such as water and food was fundamental to mantain all the members of the crew alive during the entire trip.
