As the Apollo 11 astronauts hurtled toward their historic rendezvous with the moon 47 years ago this week, they kept a hand-drawn calendar on the wall of their command module, crossing off the days of the journey as if voyagers of old.
They also scribbled labels for "smelly waste" compartments and "launch day urine bags." And after splashdown, command-module pilot Michael Collins wrote on a panel, "Apollo 11 . . . the best ship to come down the line. God bless her."
The writings, along with numerous calculations and notations on the interior, were uncovered earlier this year and late last year during an exhaustive 3-D scan of the module at the Smithsonian's National Air and Space Museum.
On Wednesday, the museum unveiled results of the scan, which show the claustrophobic interior of the module that carried Collins and fellow NASA astronauts Neil Armstrong and Buzz Aldrin to the moon and back in July 1969.
On July 20, Armstrong and Aldrin reached the moon in a landing module that had detached from the command module, where Collins remained. Armstrong then became the first person to set foot on the moon, followed by Aldrin moments later.
The two returned to the command module in an ascent vehicle, which was later jettisoned, and they came back to Earth in the command module. The mission lasted from launch on July 16 to splashdown July 24.
The Smithsonian has had the command module since 1971, said Allan Needell, who is curator in the Air and Space Museum's division of space history and oversees the Apollo program collection.
The scan shows an interior crammed with switches, buttons and dials, as well as three side-by-side seats.
The astronauts' wall writings have been known to historians but have not been widely available to scholars and the public, Needell said Wednesday.
He said the calendar, which Collins kept, was perhaps helpful because the astronauts, lacking sunrises and sunsets, wanted to keep track of the days back on Earth.
The markings give a sense of reality to the module.
"The whole wonderful thing about this is . . . because the thing is dirty and marked up and obviously lived in, it gives you a way to sort of transport yourself into the context of an artifact that . . . we don't usually provide," Needell said.
Because of its importance, he said, experts have been careful not to venture often inside the fragile command module. But the chance to scan inside would provide researchers a detailed record of life on board.
Amid the drama of the mission, for example, "it got pretty stinky in there," he said.
"There were various human functions that went on," he said. "Once they closed up some smelly waste in some locker, they didn't really want to bother to open it again until they were home."
So they labeled lockers accordingly.
Needell said the command module will be removed for conservation next year so it can be included in a future state-of-the-art gallery at the museum. The Smithsonian said the new exhibit is scheduled to open in 2020 and is titled "Destination Moon."