The Apollo command module was an eleven-foot-tall cone shaped structure, nearly thirteen feet wide at the base. The walls of the crew compartment were made of a thin sandwich of aluminium sheet and an insulating honeycomb filler. Surrounding that was an outer shell of a layer of steel, more honeycomb, and another layer of steel. These double bulkheads – no more than a few inches thick – were all that separated the astronauts inside the cockpit from the near-absolute vacuum of an outside environment where temperatures ranged from a gristle-frying 280 degrees Fahrenheit in sunlight to a paralyzing minus 80 degrees in shadow. Inside the ship, it was a balmy 72.
The astronauts’ couches lay three abreast, and were actually not couches at all. Since the crew would spend the entire flight in a state of weightless float, they had no padding beneath them to support their bodies comfortably; instead, each so-called couch was made of nothing more than a metal frame and a cloth sling – easy to build and most important, light. Each couch was mounted on collapsible aluminum struts, designed to absorb shock during splashdown if the capsule parachuted into the sea – or in the case of a mistargeted touchdown, onto land – without too much of a jolt. At the foot of the three cots was a storage area that served as a sort of second room (Unheard of! Unimaginable in the Gemini and Mercury eras!) called the lower equipment bay. It was here that supplies and hardware were stored and the navigation station was located.
Directly in front of the astronauts was a big, battleship-gray 180 degree instrument panel. The five hundred or so controls were designed to be operated by hands made fat and clumsy by pressurized gloves, and consisted principally of toggle switches, thumb wheels, push buttons, and rotary switches with click stops. Critical switches, such as engine firing and module-jettisoning controls, were protected by locks or guards, so that they could not be thrown accidentally by an errant knee or elbow. The instrument panel readouts were made up primarily of meters, lights, and tiny rectangular windows containing either “gray flags” or “barber poles.” A gray flag was a patch of gray metal that filled the window when a switch was in its ordinary position. A striped flag like a barber pole would take its place when, for whatever reason, that setting had to be changed.