Coasting to the Moon


A large part of the Apollo journey was spent in coasting flight; a period of time, usually somewhere between the Moon and Earth, when the three crewmen waited to reach a destination or when the command module pilot was waiting for his two crewmates to return from their exploration of the lunar surface. Although this part of the flight held little interest for the news media, the crew were nevertheless kept busy with a great variety of tasks ranging from the clever precision of the CMP's navigation commitment to matters of personal hygiene.

NASA made sure there was plenty to keep its crews occupied. Exotic conditions like the command module in deep space had cost the taxpayer dearly and did not occur often, unlike the continuous time in weightlessness offered by later space stations. Being in deep space meant that the crew were exposed to an environment beyond the shielding effects of Earth's magnetic field. As a result, crews found that mission planners, managers and controllers very rarely allowed them to relax during a flight. This was particularly true of later flights, when the business of just keeping the spacecraft running had become somewhat routine.

The openness with which NASA conducted its primary objective, whereby it allowed unprecedented access to most of what it did, demanded that its costly missions should at least appear to extract as much as possible from every minute of the flight even beyond the goal of reaching the Moon. If the crew were not busy dealing with the upkeep of their mini-planet or of their own bodies, they would find themselves involved in a series of scientific experiments, out-the-window observations, television broadcasts, changes to the flight plan or the execution of carefully calculated adjustments to their trajectory.

The sleep problem

NASA's manned space experience began with Alan Shepard's 5-minute sample of weightlessness in May 1961 on board the first manned Mercury spacecraft. In just eight years, through the Mercury and Gemini programmes, NASA became increasingly sophisticated in Earth-orbit operations, culminating in October 1968 with the 12-day 'shakeout' flight of Apollo 7 when the first manned Block II spacecraft was put through its paces in Earth orbit. Yet, by the time that the pioneering flight of Apollo 8 was launched towards the Moon on 21 December 1968, managers found themselves vexed by a very basic problem - the disturbed sleeping patterns of the three-man crew in the limited volume of the Apollo command module.

Throughout the early years of planning for the Apollo lunar flights, it had always been assumed that the best arrangement for sleep would be a rotation system in which at least one crew member would always be awake to monitor the systems. Apollo 7 followed this regime. Donn Eisele, the command module pilot, took his rest period alone. The commander Wally Schirra and lunar module pilot Walt Cunningham took theirs simultaneously. The crew never reported problems with this arrangement during their debriefing; although any tiredness could have been masked by the irritating head colds that they endured and the irritability that they displayed could have been exacerbated by lack of sleep. In any case, Apollo 7 was confined to Earth orbit and its crew were not in the position of being the first humans to orbit another world for 20 hours.

Things started well on board Apollo 8 with only a bout of space motion sickness from the commander Frank Borman causing any medical concern. The coast to the Moon was relatively uneventful and the crew kept the ship running smoothly. The major activity was by Jim Lovell as the CMP, who practised the cislunar navigational techniques that subsequent crews would use. However, as the spacecraft's flight progressed, the crew found that their planned sleep patterns became increasingly disrupted.

A common problem occurred whenever a crewmember spoke to mission control, as his chatter would disturb the slumber of his colleague. A possible reason for this was that, unlike an Earth-orbit mission of the time, there were no long periods during the coast when radio silence was enforced by the sparse distribution of the tracking sites. During the coast to the Moon, the flight controllers in mission control were in permanent communication with the spacecraft and the Capcom would not only speak to the crew whenever an operational need arose but would also engage in idle chat, so communication was often ongoing. Also, with three men occupying the very cramped confines of the cabin, any activity to carry out chores tended to disturb the sleeping crewman who usually slept on his couch or underneath it. In the command module, there were no sleeping bags, and no place to escape from colleagues. By the time they reached their destination, they were all somewhat groggy from their attempts at napping, and needed the adrenaline produced by the excitement of making ten orbits around an alien planet to help them to perform their duties successfully and safely.

All three men were captivated by the forbidding, stark landscape that was passing beneath their windows. They worked hard at their full schedule of photography, TV broadcasts and navigational sightings, all the time keeping up a busy chatter with mission control until the seventh orbit, when Borman decided to discard the timeline for the remainder of their orbital sojourn. Although an incredibly sophisticated machine for 1960s' technology, the spacecraft could only achieve its capability by being necessarily complex and intricate. There were countless ways in which a tired crew could kill themselves through inappropriate operation of its many controls. Borman knew this, and ordered Jim Lovell and Bill Anders to take some rest before the trans-Earth injection burn.

Mission planners took the Apollo 8 experience to heart when they reviewed the sleeping arrangements for subsequent flights. It was decided that since the controllers on the ground had a better view of the spacecraft's systems through telemetry, the crews would sleep concurrently, following Houston time, with one crewman wearing a headset in case Houston felt the need to wake them up. As subsequent missions became increasingly complex and demanding, this change in the sleep regime allowed crews to sleep well and helped them to cope more easily with the immense physical and mental strain they had to endure when their opportunity came to explore another world in the very limited time Apollo could give them.

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