The term 'launch locations' can refer to the places where rockets and other spacecraft are launched from. The four-letter solution for this term is 'PADS', which stands for 'Permanent Aerospace Development Sites'. These sites are typically large, purpose-built facilities that are designed to launch rockets and other spacecraft into space. They are usually located in remote areas, away from populated areas, and are equipped with specialized equipment and personnel to ensure a safe and successful launch.