Final answer:
The primary purpose of ground control in Houston's communication with astronauts in space is to provide detailed instructions on how to perform specific maneuvers.
Step-by-step explanation:
The primary purpose of ground control in Houston's communication with astronauts in space is to provide detailed instructions on how to perform specific maneuvers, such as docking with the International Space Station or conducting a spacewalk. Ground control acts as a support system for astronauts, guiding them through the necessary steps and ensuring safety and successful mission execution. They communicate with astronauts, providing them with step-by-step instructions and real-time guidance to perform complex tasks in the microgravity environment of space.