Youngest man on the Moon
On 16 April 1972, Apollo 16 left Earth and headed to the Moon. The mission’s Lunar Module pilot, Charles Duke, recounts the day his astronaut boots touched lunar soil
Could you tell us a bit more about how you went about choosing the landing site without crashing?
There is no dark side of the Moon; it’s actually the far side. It rotates once every 28 days. There are two weeks of daylight and two weeks of night on every spot of the lunar surface. Apollo 16 landed with a low Sun angle to give us definition of the lunar surface. If you tried to land at high noon, it was all washed out by sunlight, which meant that you couldn’t see any of the craters and you couldn’t see any of the elevation changes. The landing site was therefore chosen at a very low Sun angle, so that we had all of the shadows to the west. It was early morning during the lunar day at the Apollo landing site, which was called Descartes. We got some definition of the landing site, which meant that we didn’t crash or fall into a big crater. The further east you go, the more the backside of the Moon was in darkness. We landed just a little east and a little south of the centre and could see that half of the backside of the Moon was in sunlight.
What did you see as you entered lunar orbit?
As we entered the shadowed portion of the Moon, you got this eerie feeling because the Sun hadn’t been shining on this region for a few days. The feeling was so unreal that I was left thinking: ‘Well, I hope our tracking is right!’ You’re going into orbit at 60 by 70 miles [97 by 113 kilometres] above the Moon. And so we burned to slow down and manoeuvre into orbit. At this point, the computer told us that we were out of contact with Earth and that we had loss of signal. Then, all of a sudden there was the sunrise – it was the most dramatic sunrise I’ve ever seen. In Earth orbit, you see the Sun’s glow on the horizon, or the planet’s atmosphere, and it gets brighter and brighter. The Moon is different though – there’s instant sunlight, with long shadows on the lunar surface. The far side of the Moon was very rough back there. I would not have wanted to land on the backside of the Moon.
The manoeuvre into orbit lasted around two minutes and 41 seconds. During that time, we burned about 2 million kilograms of fuel. We took pictures of Earth after we left our planet over Australia around an hour after liftoff. Earth was like a jewel suspended in the blackness of space. The Sun shines all of the time on the way to the Moon, but the stars are never visible.
It’s very dark when you look outside and all you see is the Earth, Moon and Sun.
Why didn’t you land on the far side of the Moon?
We wanted to be in contact with Earth, so we weren’t able to land on the backside of the Moon. We ended up landing at a
place called Descartes – our landing site was in the Descartes Highlands. We were the fifth mission to land on the Moon and I can say that it really is a dramatic place. We had to lower the spacecraft further down into orbit by about 60 by 8 miles
[97 by 13 kilometres]. That would be the orbit in which we would attempt to land. At this point we needed a critical burn of the main engine, because if you had one second overburn, you ended up impacting the Moon’s surface. As we were lowering ourselves, we looked out of the window as we came around from the backside of the Moon to make sure that we weren’t going to crash into its surface. If we felt like we were going to, then we would have had to bail out.
“If the roving vehicle broke down then we would have had to walk back – there’s no rescue on the Moon”
Your Command Module pilot Ken
Mattingly was meant to go on a mission to the Moon before you… what happened?
Mattingly was supposed to be on Apollo 13, but I caught measles a week before the launch and exposed him to the measles, so they jerked him off the flight and we ended up on a flight together.
What was liftoff like?
Everybody went to the Moon on a Saturn V rocket. At liftoff the engines were producing 3.5 million kilograms of thrust, so you didn’t lift off very fast, but you were shaking like crazy from side to side. I got a little bit nervous – you don’t see outside of Apollo at this point. The windows were covered over, so I got a little bit nervous and my heart was pounding. I said: “I hope this thing makes it,” because the vibration was so intense. Later on, when we returned to Earth, I spoke to the flight surgeon who was based at Mission Control and asked what my heart rate was. He said that “it was 144 beats per minute – you were excited!” I replied: “You bet I was excited!” I then asked what John Young’s was, and apparently his was 70, so he was the cool one.
What did you do as soon as you landed?
We were supposed to go outside right after we landed, but we didn’t get the chance. Instead we went to sleep and had a rest period. That was pretty hard to do, three hours after we landed on the Moon. With a sleeping pill though, I was able to do it.
Could you describe the moment you left the Lunar Module?
I opened the door, got on my hands and knees and crawled out backwards down the ladder and onto the footpath. From the door to the footpath, to give you some idea, is about five metres [16 feet] in height. Descartes had some mountains and plains, as well as a big valley, which was about ten kilometres [6.2 miles] wide. We would explore this valley over our three-day stay. You could see the shadows of the Sun in the
direction of Stone Mountain. The Sun was always in the west while we were on the surface.
We drove further afield on our second extravehicular activity. It was about four kilometres [2.5 miles] from where we landed. We were actually going to go out as far as 100 kilometres [62 miles], but we didn’t drive that far, because if the roving vehicle broke down then we would have had to walk back – there was no rescue up on the Moon!
How did the Moon feel underfoot?
The Moon is covered with this very fine dust, like a powder, which is actually pulverised rock. When we walked on it, we didn’t sink any further than a couple of inches. One of the problems in the beginning was that some of the scientists thought that we were going to land in lunar dust that was 200 to 300 metres [656 to 984 feet] deep and we were going to sink when we stepped outside.
Did you get a chance to study the Moon’s surface?
We could see the western horizon from our location. We could see a place called North Ray crater, and all of the white rocks in our area were from the meteor impact that made that crater. We collected three colours of rocks – grey ones, white ones and black ones. Lesson number one in geology is to pick up a rock in every colour, and so we were able to get the whole suite of Moon rocks. We collected about 98 kilograms of lunar soil. We also had a whole suite of experiments: two seismic experiments, a mass spectrometer and a heat flow experiment, which unfortunately failed. We also had two magnetometers.
To the west of where we landed was Plum crater. It was about two metres [6.6 feet] deep – or perhaps a bit deeper. We gave it a wide berth because we didn’t want to fall into it. As I said earlier, there’s no rescue on the Moon, and we wouldn’t be able to get out. We got a good view of the lunar surface during the mission. We got plenty of samples and a good view of the lunar colours – there were different shades of grey. We collected rocks with different shovels, rakes and tongs.
We could see for a long way from Stone Mountain, which is the furthest we got on the mission, and the lunar plains glistened in the sunlight. It was very bright on the Moon, so we had our visors down at all times. In some places, our footprints were barely there because the lunar soil was so thin. I drilled three holes in the Moon, around three metres [9.8 feet] deep, and the soil was still quite solid. In some areas on the lunar surface, it was like walking on a solid floor. There was no dust at all.
What did Earth look like from the Moon?
From where we stood on the Moon, Earth was directly overhead. And it stayed there. I did see Earth from lunar orbit, but not from the Moon. If you look up, you’re looking at the top of your helmet – this part of your spacesuit doesn’t move back with your head. I only ever saw Earth when I fell backwards one time – it scared me half to death! I fell back and said: “Oh yeah, there it is!” It’s a good job that I knew how to get back up again because I would still be on the Moon.
Apollo 11’s Neil Armstrong and Buzz Aldrin left a flag on the Moon. Did you leave your mark in a similar way?
I left a picture of my family on the Moon. People wondered why I did that, but I really wanted to get my family involved in the mission. We were travelling and training all of the time, and so I asked them: “Would you like to be on the Moon with me?” My children said: “We sure would!” So we took this picture of the family and on the back of the picture we wrote, this is the family of astronaut Duke from Planet Earth. Landed on the Moon, April 1972. We all signed the picture. It’s still there. The lunar rover is still there also, and we left the TV camera running on the front of it. The rover could travel at a maximum speed of 17 kilometres [10.6 miles] per hour. Up on the Moon, which only has 17 per cent of Earth’s gravity, it felt like you were flying.
On your return to Earth, where did you land?
We splashed down in the Pacific Ocean, and the three parachutes started to open before fully deploying as we landed in the water. It was one of the most beautiful sights I ever saw. We were grateful for the parachutes – without them the spacecraft would have hit the water with such force that Apollo 16 would have split open and we would have sunk to the bottom of the ocean.