 During the flight , three fellow astronauts served on the ground as Capsule Communicators ( usually referred to as " CAPCOMs " ) on a rotating schedule . The CAPCOMs were the only people who regularly communicated with the crew . Michael Collins was the first CAPCOM on duty and at 2 hours , 27 minutes and 22 seconds after launch radioed , " Apollo 8 . You are Go for TLI . " This communication signified that Mission Control had given official permission for Apollo 8 to go to the Moon . Over the next 12 minutes before the TLI burn , the Apollo 8 crew continued to monitor the spacecraft and the S @-@ IVB . The engine ignited on time and performed the TLI burn perfectly . 
