362: Total mass of Moonrocks collected, in kilograms
The Apollo programme was conceived as a political challenge to beat the Russians to the Moon. It became an engineering challenge to achieve that goal and, finally, a scientific challenge to make sure the astronauts did something useful when they got there.
Key to this was training the Apollo crews in field geology. As well as classroom sessions, the astronauts took part in field trips to Hawaii, Mexico, Iceland and Germany. They learned about rock formations, volcanoes and meteorite impact craters.
“It was great fun,” says Apollo 15 command module pilot, Al Worden. “We built up a picture in our minds of what we were looking for.”
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On the Moon, astronauts were equipped with hammers, scoops and drills. Meanwhile, command module pilots in lunar orbit, like Worden, made observations over much larger areas.
“I flew over the landing areas describing the large general features that would complement what they found on the surface,” says Worden. “I think that really helped paint a picture of the Moon.”
The first (and only) geologist to visit the Moon was Harrison Schmitt. During his Apollo 17 mission, he discovered orange beads of rock – strong evidence of volcanic activity on the Moon. The crew brought back some 741 samples, weighing a massive 111kgs (244lb).
The astronauts brought back more than 360kg (790lb) of Moon rocks for study on Earth (Credit: Nasa)
The 2,200 rock and soil samples collected on the Moon were taken to the lunar receiving laboratory in Houston. Although for Apollo 11 at least, the astronauts had to fill in a customs declaration first.
Moon rocks have since been donated to governments, museums or lent to scientific institutions for study. Others have remained sealed in their containers, untouched since they were collected.
Analysis of the samples has revealed the history of the Moon and provided compelling evidence that the Earth and Moon formed as a result of a giant impact between an early planet and another astronomical body.
60: Number of miles travelled on the Moon
Mission controllers were keen that Neil Armstrong and Buzz Aldrin didn’t stray far from the lander, their ride home. The furthest the crew walked was to a nearby crater, achieving a total distance of around half a mile.
But as the missions progressed, and the time spent on the surface increased, the astronauts walked further. Even in 1/6th gravity, however, bounding across the Moon was tiring and their range was limited.
The lunar driving record is still held by the last man on the Moon, Gene Cernan
During Apollo 15 in 1972, Dave Scott and Jim Irwin got to drive the first lunar rover. With a maximum speed of 10mph (16km/h), the electric vehicle carried them some 14 miles.
“The rover handles quite well… I can manoeuvre pretty well,” reported Scott to mission control. “It negotiates small craters quite well but it feels like we need the seatbelts.”
“Just like in the owner’s manual, Dave,” replies the ground.
The lunar driving record is still held by the last man on the Moon, Gene Cernan. During his Apollo 17 landing with Harrison Schmitt, he notched-up 22 miles (35km) on the clock – travelling a maximum of four miles from the spacecraft.
4.5: Lunar module habitable volume, in cubic metres
After the intensity of the lunar landing and two and a half hours walking on the Moon’s surface, Neil Armstrong and Buzz Aldrin sealed the hatch on their lander and re-pressurised the cabin. They were exhausted. Before blasting-off back to the command module in orbit, they were scheduled to sleep.
“The rest period was almost a complete loss,” Armstrong later wrote in his mission report. “Noise, lighting and a lower-than-desired temperature were annoying.”
On foot and by rover, the Apollo astronauts covered some 60 miles of the lunar surface (Credit: Nasa)
Although the lunar module proved to be a great spacecraft, as a habitation module it was far from comfortable. The bulky cylinder of the ascent engine cover – rising like a barrel in the middle of the cabin – meant there was little floor space.
Armstrong attempted to sleep on the engine cover and Aldrin on the floor.
“The window shades did not completely block out light, the cabin was illuminated by a combination of light through the shades, warning lights and display lighting,” Armstrong complained.
During later missions, astronauts slept in their underwear in hammocks
“The noise from the glycol pumps was then loud enough to interrupt sleep,” he added. “The lunar module pilot [Aldrin] estimated that he slept fitfully for perhaps two hours and the commander did not sleep at all.”
During later missions, astronauts slept in their underwear in hammocks. Nevertheless, with all the excitement of being on the Moon, only a few reported getting a good night’s sleep.
7: Maximum re-entry velocity, in miles per second
27 December 1968, the crew of Apollo 8 were about to become the fastest people in history. Having travelled to the Moon, Frank Borman, Jim Lovell and Bill Anders prepared to re-enter the Earth’s atmosphere. They were travelling at 36,303 feet per second (nearly seven miles per second).
This would be the ultimate test of the Apollo command module and its resin heat shield, designed to protect the crew from temperatures of up to 3,000C (5,432F).
“We used the atmosphere to slow us down,” Borman says. “From a physical standpoint it was the most arduous part of the mission because you’re pulling six gs for quite a long time and it becomes hard to breathe.”
“It was like flying inside of a neon light or a blowtorch – it was the most dramatic part of the flight.”
The lunar lander was a brilliant piece of engineering - but it had few creature comforts for its two-man crew (Credit: Nasa)
But it wasn’t the most uncomfortable. Splashing down at night in the Pacific Ocean, the spacecraft tipped upside down, leaving the astronauts hanging in their seats.
“The spacecraft was a lousy boat,” Borman says. “We had to wait about two hours till daylight because the Navy didn't want to put divers in when there were sharks.”
“I got seasick and threw-up all over Anders and Lovell,” he says. “I still hear about that to this day.”
Their speed record didn’t last for many months. The record for the fastest re-entry and, therefore, the record for the fastest speed ever attained by humans, goes to the Apollo 10 crew. In May 1968, they returned to Earth at 36,397 feet per second – that’s 24,816mph (39,705km/h).
(You can hear more about Apollo 8 here.)
238,855: Distance to the Moon, in miles
After the intensity of launch, some astronauts felt that travelling to the Moon was pretty dull.
“Three and a half days we had nothing to do,” says Apollo 15 command module pilot, Al Worden. “All we had to do was wait till we got to the Moon and that's a pretty boring time.”
The reason we know the average distance to the Moon with such accuracy is thanks to one of the experiments deployed on the surface during Worden’s mission
As the Earth receded behind them, astronauts chatted, read, listened to music or tried to exercise using resistance bands. They also took part in TV broadcasts. You could liken it to being confined to a small car with two work colleagues, occasionally livestreaming the experience.
“There are few moments during the day during the outbound trip where we would make little course corrections,” he adds. “That's the most exciting thing we did on the way out.”
The crew had three and a half mostly uneventful days on the journey between the Earth and the Moon (Credit: Nasa)
The reason we know the average distance to the Moon with such accuracy is thanks to one of the experiments deployed on the surface during Worden’s mission. Astronauts on Apollo 11, 14 and 15 left behind devices called Laser Ranging Retroreflectors (LRR). These special mirrors were designed to reflect lasers aimed through telescopes from Earth. (Incidentally, if you wanted to translate that distance into marathons, you’d have to run 9,186 of them to match it.)
They are still used today and have given astronomers an improved understanding of the Moon’s orbit. They have also discovered that the Moon is getting further away from Earth – it’s currently receding at 38mm a year.
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