During Apollo 11, Neil Armstrong and Buzz Aldrin traveled to the Moon's surface in the lunar module. Michael Collins remained in the command module, carrying out his work in lunar orbit.
The three astronauts' different roles made the landing and return possible. After leaving the surface, the lunar module had to rendezvous with the command module, making orbital operations essential to the mission.
Columbia in lunar orbit
During his day flying solo around the Moon, Collins never felt lonely. Although it has been said "not since Adam has any human known such solitude", Collins felt very much a part of the mission. In his autobiography he wrote: "this venture has been structured for three men, and I consider my third to be as necessary as either of the other two". In the 48 minutes of each orbit when he was out of radio contact with the Earth while Columbia passed round the far side of the Moon, the feeling he reported was not fear or loneliness, but rather "awareness, anticipation, satisfaction, confidence, almost exultation".
One of Collins' first tasks was to identify the Lunar Module on the ground. To give Collins an idea where to look, Mission Control radioed that they believed the Lunar Module landed about 4 miles (6.4 km) off target. Each time he passed over the suspected lunar landing site, he tried in vain to find the module. On his first orbits on the back side of the Moon, Collins performed maintenance activities such as dumping excess water produced by the fuel cells and preparing the cabin for Armstrong and Aldrin to return.
Just before he reached the dark side on the third orbit, Mission Control informed Collins there was a problem with the temperature of the coolant. If it became too cold, parts of Columbia might freeze. Mission Control advised him to assume manual control and implement Environmental Control System Malfunction Procedure 17. Instead, Collins flicked the switch on the system from automatic to manual and back to automatic again, and carried on with normal housekeeping chores, while keeping an eye on the temperature.
When Columbia came back around to the near side of the Moon again, Collins was able to report that the problem had been resolved. For the next couple of orbits, he described his time on the back side of the Moon as "relaxing". After Aldrin and Armstrong completed their EVA, Collins slept so he could be rested for the rendezvous. While the flight plan called for Eagle to meet up with Columbia, Collins was prepared for a contingency in which he would fly Columbia down to meet Eagle.
Lunar ascent
Aldrin entered Eagle first. With some difficulty the astronauts lifted film and two sample boxes containing 21.55 kilograms (47.5 lb) of lunar surface material to the LM hatch using a flat cable pulley device called the Lunar Equipment Conveyor (LEC). This proved to be an inefficient tool, and later missions preferred to carry equipment and samples up to the LM by hand. Armstrong reminded Aldrin of a bag of memorial items in his sleeve pocket, and Aldrin tossed the bag down. Armstrong then jumped onto the ladder's third rung, and climbed into the LM. After transferring to LM life support, the explorers lightened the ascent stage for the return to lunar orbit by tossing out their PLSS backpacks, lunar overshoes, an empty Hasselblad camera, and other equipment. The hatch was closed again at 05:11:13. They then pressurized the LM and settled down to sleep.
Presidential speech writer William Safire had prepared an In Event of Moon Disaster announcement for Nixon to read in the event the Apollo 11 astronauts were stranded on the Moon. The remarks were in a memo from Safire to Nixon's White House Chief of Staff H. R. Haldeman, in which Safire suggested a protocol the administration might follow in reaction to such a disaster. According to the plan, Mission Control would "close down communications" with the LM, and a clergyman would "commend their souls to the deepest of the deep" in a public ritual likened to burial at sea. The last line of the prepared text contained an allusion to Rupert Brooke's World War I poem "The Soldier".