Here, I present for you a snippet from the Western Electric document
Introduction to Project Mercury and Site Handbook on one of the most important aspects of a space program that barely existed; ground control and monitoring. You know, the part where they actually know what the astronaut and his capsule are doing and decide whether or to send him into space and bring him back down, a wholly unnatural act.
a. Direct the entire flight in respect to the mission;
b. Monitor the flight in respect to aeromedical and capsule systems;
c. Keep the astronaut and range stations informed of mission progress;