The Fra Mauro hills stand a couple of hundred kilometres to the east of the Apollo 12 landing site. Apollo 13 was supposed to land there so the site was reassigned to Apollo 14, because scientists gave that area a high priority.
In what is the most remarkable comeback in space history, the commander of the mission was Alan Shepard. He was one of the original Mercury 7 and the first American to fly in space. He had been slated for the first Gemini mission but then contracted Ménière’s disease and was grounded.
In 1968, fellow astronaut Tom Stafford told Shepard that an otologist in Los Angeles had developed a cure for Ménière’s disease. Shepard flew to Los Angeles, to see Dr William F. House. House proposed to open Shepard’s mastoid bone and make a tiny hole to drain excess fluid. The surgery was conducted in early 1969 at St Vincent’s Hospital in Los Angeles, where Shepard checked in under the pseudonym of Victor Poulos. It was successful, and he was restored to full flight status a few months later.
Being in charge of astronaut crew selection, Shepard and Slayton put Shepard down to command the next available Moon mission, Apollo 13 in 1970. Under the normal crew rotation procedure Cooper, as the backup commander of Apollo 10, would have been chosen, but Cooper was swept aside. Stuart Roosa, who had not made a spaceflight before was designated the Command Module Pilot and Shepard wanted Jim McDivitt as his Lunar Module Pilot. McDivitt, who had already commanded Apollo 9, was not impressed, saying that Shepard did not have sufficient Apollo training to command Apollo 13. Curiously, another astronaut who hadn’t flown in space before, Edgar Mitchell, was then designated as the Lunar Module Pilot.
Slayton had to get approval for flight crew assignments from George Mueller, who rejected the Apollo 13 assignments saying the crew was too inexperienced. Slayton then asked Jim Lovell, the backup commander for Apollo 11, and slated to command Apollo 14, if his crew would be willing to fly Apollo 13 instead. He agreed, and Shepard’s inexperienced crew was assigned to the Apollo 14 so that they could get more training. Neither Shepard nor Lovell expected there would be much difference between Apollo 13 and Apollo 14. The failure of Apollo 13 meant that Apollo 14 was delayed until 1971, so that modifications could be made to the spacecraft.
In September, NASA announced that the last two Apollo missions had been cancelled. Visitors to President Nixon’s Oval Office noticed that the copy of the Apollo 8 ‘Earthrise’ picture that had been placed on the wall in December the year before had been taken down. The fact was that whenever government cuts were proposed, NASA was at the top of the list.
With Apollo 14 under way, a major problem occurred on 5 February, just prior to the final descent at Fra Mauro, when Shepard and Mitchell were in the LM, ‘Antares’. An abort command was received by the Lunar Module’s guidance computer. Had the abort command been initiated, it would have separated the ascent stage from the descent stage, ending the landing altogether. As it was, the descent had to be delayed as Mission Control investigated. They concluded that the problem was that the abort switch itself was faulty. A computer program was written and tested within two hours by the operations team and inserted manually into the computer by Mitchell. According to Shepard, the targeting data for the Apollo 14 landing site were every bit as good as the data for Apollo 12; nevertheless, they had to fly around for a little while. As for Apollo 12, this was because the landing site was rougher, on direct observation, than the photos had indicated.
On the first moonwalk Shepard and Mitchell set up the solar-wind experiment and the flag, and deployed the surface science package. The latter had two new experiments. One was called the ‘thumper’: Ed Mitchell set up an array of geophones, and then walked out along a planned survey line with a device that could be placed against the surface and fired, to create a local impact of known size. Thirteen of the 21 charges went off, with good results. The other experiment was a grenade launcher, with four grenades to be fired off by radio command sometime after they had left the Moon. They were designed to impact at different distances from the launcher, to get a pattern of seismic response to the impact explosions. While the moonwalkers were performing their tasks, Stuart Roosa was obtaining photographic coverage of the proposed site for the Apollo 15 mission, near the Descartes crater.
During their first moonwalk, Shepard and Mitchell worked on the surface for four hours and 50 minutes. For their second EVA they used the MET – Modularized Equipment Transporter, although they called it the lunar rickshaw – to carry tools, cameras, and samples so they could work more effectively and bring back a larger quantity of samples. According to Shepard:
Our planned traverse was to take us from Antares more or less due east to the rim of Cone crater. That traverse had been chosen because scientists wanted samples and rocks from the crater’s rim. The theory is that the oldest rocks from deep under the Moon’s surface were thrown up and out of the crater by the impact, and that the ones from the extreme depth of the crater were to be found on the rim.
On our way to the crater, one of the first things Ed did was to take a magnetometer reading at the first designated site. When he read the numbers over the air, there was some excitement back at Houston because the readings were about triple the values gotten on Apollo 12. They were also higher than the values Stu was reading in the Kitty Hawk [the Command Module], and so it seemed that the Moon’s magnetic field varied spatially. Our first sampling began a little further on, in a rock field with boulders about two or three feet along the major dimension. These were located in the centers of a group of three craters, each about sixty feet across. Like the bulk of the samples brought back, these were documented samples. That means photographing the soil or rocks, describing them and their position over the voice link to Mission Control, and then putting the sample in a numbered bag, identifying the bag at the same time on the voice hookup.
The mapped traverse was to take them nearly directly to the rim of Cone crater, a feature about 300 m in diameter. As they approached, the boulders got larger, up to 1.5 m in size. And at this time, the going started to get rougher:
The terrain became more steep as we approached the rim, and the increased grade accentuated the difficulty of walking in soft dust. Another problem was that the ruggedness and unevenness of the terrain made it very hard to navigate by landmarks. Ed and I had difficulty in agreeing on the way to Cone, just how far we had travelled, and where we were.
As they moved towards Cone, into terrain that had almost continuous undulations, and very small flat areas, the surface began to slope upward even more steeply, and they felt they were starting the last climb to the rim of Cone. They passed a rock which had a lot of glass in it, and reported to Houston that it was too big to pick up. As they continued, they altered their suit cooling rate to match their increased work output as they climbed. For a while, they picked up the cart and carried it, preferring to move that way because it was a little faster. And then came what had to be one of the most frustrating experiences on the traverse. Shepard tells the story:
We thought we were nearing the rim of Cone, only to find we were at another and much smaller crater still some distance from Cone. At that point, I radioed Houston that our positions were doubtful, and that there was probably quite a way to go yet to reach Cone. About then, there was a general concurrence that maybe that was about as far as we should go, even though Ed protested that we really ought to press on and look into Cone crater. But in the end, we stopped our traverse short of the lip and turned for the walk back to Antares.
Later estimates indicated they were perhaps only 10 m or so below the rim of the crater, and yet they were not able to define it in that undulating and rough country.
We stopped at Weird crater, for more sampling and some panoramic photography, and then continued the return traverse. At the Triplet craters, more than three-quarters of the way back to Antares, we stopped again. Ed’s job there was to drive some core tubes; I was to dig a trench to check the stratification of the surface. But the core material was granular and slipped out of the tube every time Ed lifted it clear of the surface. I wasn’t having any better luck with my trenching, because the side walls kept collapsing. I did get enough of a trench dug so that I could observe some stratification of the surface materials, seeing their colour shift into the darker browns and near blacks, and then into a surprisingly light-coloured layer underneath the darkest one.
By the time they got back to Antares they had covered a distance of about 3 km and collected many samples during four and a half hours on the surface in the second EVA. ‘I also threw a makeshift javelin, and hit a couple of golf shots,’ said Shepard. ‘That was our mission. Our return was routine, our landing on target, and our homecoming as joyous as those before.’ He continues:
I look back now on the flights carrying Pete’s crew and my crew as the real pioneering explorations of the Moon. Neil, Buzz, and Mike in Apollo 11 proved that man could get to the Moon and do useful scientific work, once he was there. Our two flights – Apollo 12 and 14 – proved that scientists could select a target area and define a series of objectives, and that man could get there with precision and carry out the objectives with relative ease and a very high degree of success. And both of our flights, as did earlier and later missions, pointed up the advantage of manned space exploration. We all were able to make minor corrections or major changes at times when they were needed, sometimes for better efficiency, and sometimes to save the mission.
Apollo 12 and 14 were the transition missions. After the cart towed by the moonwalkers of Apollo 14 came the Lunar Rover: a wheeled vehicle to extend greatly the distance of the traverse and the quantity of samples that could be carried back to the Lunar Module.
In July 1971 Apollo 15 hit its target precisely, a large amphitheatre girded by mountains and a deep canyon on the eastern edge of a vast plain. Later, Commander David Scott said he would never forget the Command Module, ‘Endeavour’, hurtling through the Moon’s strange nighttime. Above were the stars, below lay the Moon’s far side, an arc of impenetrable darkness. As the moment of sunrise approached, barely discernible streamers of light – actually the glowing gases of the solar corona around the Sun – played above the Moon’s horizon. Finally, the Sun exploded into his view. In less than a second its harsh light flooded Endeavour and dazzled his eyes. The early lunar morning stretched into the distance. Long angular shadows accentuated every hill and crater. As the Sun rose higher, the moonscape turned the colour of gunmetal.
Dave Scott and Jim Irwin spent 67 hours on the Moon, landing in the bright morning of the 710-hour lunar day. Opening the top hatch, Scott made a preliminary survey, looking out on a world he described as still being in the epoch of its creation. Craters left by ‘recent’ meteorites millions of years ago stood out startlingly white against the soft beige of the gently undulating terrain. The Lunar Module, ‘Falcon’, had landed on the edge of the so-called Sea of Rains – Mare Imbrium – which stretches across a swathe of the Moon for over 1,000 km. To the south of Falcon, a 3,300-m ridge rose over the plain. To the east was an even higher summit. To the west was the Hadley Rille, snaking across the landscape and 300 metres deep. To the north-east was a great mountain towering 5,000 metres above them. ‘Their majesty overwhelmed me,’ said Scott.
Scott was a space veteran on his third flight but he was also a new breed of astronaut. Eight years of training in lunar geology made him aware of intriguing details in the landscape and the rocks – a dark line, like a bathtub ring, smudged the base of the mountains. Was it left by the subsiding lake of lava that once filled the immense cavity of Palus Putredinis on the fringes of Mare Imbrium billions of years ago?
On the surface, Scott found the one-sixth Earth gravity more enjoyable than weightlessness, in that it retained the same sense of buoyancy but with a reassuringly fixed sense of up and down. He felt like an intruder, he said, in an eternal wilderness. The flowing moonscape reminded him of the Earth’s uplands after a covering of snow. Most of the scattered rocks shared the same greyness as the dust. However, he found two that were jetblack, two that were pastel green, several with sparkling crystals, some coated with glass and one that was white. No wind blew, no sound echoed, only shadows moved.
At first, Dave Scott and Jim Irwin experienced a troubling deception in perspective. There were no trees, clouds or haze to determine whether an object were far or near. Each of the three spacewalks was due to last seven hours and they dug and drilled, gathered rocks, took photographs. Back in Falcon between excursions, it took them two hours to remove their suits and do housekeeping chores. For the first twenty minutes or so they were aware of a smell like that of gunpowder, before the air filtration system purified the air. The moondust stuck to everything. To sleep, they put shades over the windows before settling into hammocks.
By the third moonwalk they felt at home. Using the Lunar Rover on its first mission they ventured over the horizon – the first astronauts ever to do so. In case of problems with the navigation system on the rover, Scott had made a small cardboard compass that used the Sun’s position as a reference since its position didn’t change much during their brief stay. Although shrivelled in the savage lunar sunlight and covered with moondust, it would give him the bearings back to Falcon if he were to need them. On their way back the astronauts even dared to take a short cut, the rover bouncing between undulations and crater walls that obscured their view of the Lunar Module for long minutes.
At leaving the Moon they felt a sense of impending loss. They would never return to the plains of Hadley. Clutching the ladder, Scott raised his eyes from the now-familiar moonscape and saw the vivid blue sphere of the Earth.
On the descent stage of the lander, as with all Apollo landers, a plaque of aluminium portrayed the two hemispheres of Earth, as well as giving the name of the spacecraft, the date of the mission and the roster of the crew. The crew of Apollo 15 left behind a falcon’s feather and a four-leaf clover. In a little hollow in the moondust they placed a stylized figure of a man in a spacesuit alongside a metal plaque bearing the names of the fourteen Russian and American spacemen who have given their lives so that man may explore the cosmos. Alongside, Scott lays a single book, the Bible.
In April 1972 Charles Duke, the astronaut who communicated with Armstrong and Aldrin as they landed on the Moon, got his chance to make his own landing with Apollo 16 – although when they reached lunar orbit, a malfunction in the Service Module controlling the angle of the booster nozzle nearly caused the cancellation of the lunar landing.
One of the Command Module pilot Ken Mattingly’s tasks was to fire the Service Propulsion System engine to adjust his orbit from an ellipse into a near-circular one to enable a three-day program of lunar science with the instruments in the Service Module. Mattingly went through the procedure and suddenly the CSM, named ‘Casper’, shuddered.
‘I have an unstable yaw gimbal No. 2,’ he radioed to Young and Duke.
‘Oh, boy,’ replied Young, who knew it could cancel the landing.
In consultation with Mission Control, four hours later, it was decided to use a secondary system to control the burn. What no one except Mattingly knew was that all of the rocket motor’s control signals – main and backup – used the same cable. After Apollo 16 returned to Earth, it was said by Mission Controllers that had they known about the cable, they would never have allowed the landing.
Another problem with communications meant that Young and Duke had to start their descent with the windows pointed out to space and just depend on the landing radar to update them on their altitude. Duke says:
So at 7,000 feet, the guidance program manoeuvred the vehicle to windows forward down, and I saw the lunar surface close up for the very first time. It looked exactly like the mock-up. ‘John, there it is!’ you know, ‘There’s Gator. There’s Lone Star and North Ray Crater.’
John Young descended the ladder of the LM and became the ninth man on the Moon. ‘There you are, our mysterious and unknown Descartes highland plains,’ he said. ‘Apollo 16 is gonna change your image!’
Looking back, Duke describes the mission:
We landed in the Descartes highlands of the Moon – a valley 8 to 10 miles across, and the objective was to explore to the south to a place we called Stone Mountain and then to the north, 3 or 4 miles, to a place called North Ray Crater, which was at the base of the Smoky Mountains. With the rover, you could do that. It took us 40–50 minutes to drive down south; and I was the navigator. We had trained, so I was the navigator; and John was the driver of the rover.
We landed within a couple of hundred meters of where we thought we were going to land. So we […] basically recognized the major landing spots. And I remember as John started off, I said, ‘Okay, John. Steer 120 degrees for 1.2 kilometres, and then turn left to 090 degrees and go another 2 kilometres’ or whatever it was. And so, that’s the way we navigated. The lunar rover had a little directional gyro. There was no magnetic field on the Moon, so a magnetic compass wouldn’t work. So we had a little gyroscope that was mounted in the instrument panel of the rover. We had a little odometer on the wheel that counted out in kilometres, and so that was our distance. And so, that’s how we navigated up on the lunar surface. We’d start out one direction and we’d make a big loop and come back to the lunar module 6–7 hours later. That was the plan. And, you never really worried about getting lost up there because everywhere you drove, you left your tracks. And so, if you really were unsure of your position, it was easy just to turn around and follow your tracks back.
We kept jogging and jogging, and the rock kept getting bigger and bigger and bigger. And we were going slightly downhill, that we didn’t sense at first, and so we get down to this thing and we called it ‘House Rock’. You know, it must’ve been 90 feet across and 45 feet tall. It was humongous. And we walked around to the front side or the east side, which was in the sunlight, and, you know, it was towering over us and John and I hit it with a hammer, and a chunk came off, and we were able to collect a piece of House Rock. But – then we had to hike back. It was uphill, and it was a struggle getting back up.
Before he left, Charlie Duke left on the surface a picture of his family. A message on the back reads: ‘This is the family of Astronaut Duke from Planet Earth. Landed on the Moon, April 1972.’ Underneath are the signatures of his wife and children.
On 6 December 1972, Gene Cernan, Harrison Schmitt and Ron Evans were in the Command Module ‘America’, on top of a fuelled Saturn 5 for the first night-time launch in US spaceflight history. The launch time was dictated by the angle of the Sun at the landing site in the Taurus-Littrow highlands when they arrived – the shadows cast had to be long enough to show sufficient relief to allow a safe landing.
Gene Cernan was making his third trip into space and his second Apollo mission, having also flown on Apollo 10. This time he was to take part in what would be the final Apollo Moon landing, along with geologist Harrison Schmitt. Originally Joe Engle was due to accompany Cernan but when it was realized that Apollo 17 would be the last such mission, NASA decided to replace him with a professional geologist who had been training for the now-cancelled Apollo 18.
With the exception of Apollo 14, the launch of which was delayed 40 minutes due to the weather conditions, every manned Apollo launch up to this point had lifted off exactly on schedule. Now, however, Apollo 17 was delayed two hours and 40 minutes, until 12:33 a.m., because of the failure of an automatic countdown sequencer in the ground equipment. Gene Cernan said later that he kept his hand very tightly on the abort switch, ‘because you never know’.
Cernan recounts the experience of landing on the Moon:
Our valley where we were to land in was surrounded by mountains on three sides that are higher than the Grand Canyon is deep, to give you some idea. So at 7,000 feet we were down among them. I mean the mountains rose above us on both sides. The valley was only 20 miles long and about five miles wide. We had good photography. So [we] practiced this 100, 500, I don’t know how many times. So what I was looking at I’d seen before basically, because of the simulation and the pictures. So I knew we were in the right spot. At 7,000 feet as the craters and rocks and the boulders and so forth began to appear I could begin to pick up my landing site.
We had a particular target point, but it was only as good as we expected it to be. But when I got closer and I could see, then I could what we called re-designate where we were going to land. As I say, all the way down the engine is firing, you’re in a suit, it’s noisy, it’s vibrating, people are talking to you from both ends, needles are going left and right. You know you don’t have much fuel. So you got to get down quickly. But you can’t get down too quick, you got to have your rate of descent under control.
You get down to 200 feet and you’re going to land or crash because if something happens to the descent engine at that point in time you can’t react quick enough to stage the two vehicles, fire the ascent engine, and get out of there. So when you’re down below 200 feet you’re going to land. I mean I wasn’t going to go all that way a second time and not land. Fortunately everything worked well for us. The landing radar, all the equipment, everything worked fine. You’re coming down pretty fast through 200 feet. I don’t remember exactly, but somewhere around 30, 35 feet per second, which is pretty fast, you’ve got to slow down from that point on so that you touch down at one or two feet per second. You get to about 80 feet, and you start blowing dust all over the place. By that time you now know where you’re going to land, the dust keeps you from really seeing much of anything, because it just scatters horizontally in all directions. You effectively take what you got.
‘It could have been two seconds, ten seconds, a minute or two, I don’t know. But after we all got our breath and realized ‘hey, we are there’, that’s when I told Houston, ‘Houston, the Challenger has landed.’ There have been people who want to believe in the fantasy or the conspiracy, whatever, that it was all done in Hollywood, we never really walked on the Moon. Well, if they want to have missed one of the greatest adventures in the history of mankind, that’s their choice. But once my footsteps were on the surface of the Moon, nobody, but nobody, could ever […] take those footsteps away from me. Like my daughter’s initials I put into the Moon during that three days we were there. Someone said, ‘How long will they be there?’ I said, ‘Forever, however long forever is.’ I’m not sure we, any of us, understand that.
As Cernan and Schmitt ranged over the Moon, back in Houston Cernan’s daughter Tracy was interviewed on The Today Show. She was asked if her father was bringing her back something special. ‘I can’t tell you,’ she said. The interviewer persisted. She gave in. ‘He’s going to bring me back a Moonbeam.’
Soon it was time to leave the Moon for the final time. With a waning gibbous Earth in the black sky above him, Cernan said goodbye.
When I climbed up the ladder for that last step, and I looked down, and there was my final footsteps on the surface, and I knew I wasn’t coming back this way again, somebody would – and somebody will – but I knew I was not going to come back this way. I looked over my shoulder because the Earth was on top of the mountains in the southwestern sky. Never moved for the whole three days we were there. People kept saying, ‘What are you going to say, what are going to be the last words on the Moon?’ I never even thought about them until I was […] basically crawling up the ladder.
‘As I take man’s last step from the surface, back home for some time to come – but we believe not too long in the future – I’d like to just say what I believe history will record – that America’s challenge of today has forged man’s destiny of tomorrow. And as we leave the Moon at Taurus-Littrow, we leave as we came and, God willing, as we shall return with peace and hope for all mankind.’
On the leg of the descent stage of ‘Challenger’, the Lunar Module, is a plaque that reads: ‘Here Man completed his first explorations of the Moon. December 1972 AD. May the spirit of peace in which he came be reflected in the lives of all mankind.’ Nearby, next to the abandoned Lunar Rover, drawn in the lunar soil, are the initials, TDC, standing for Tracy Dawn Cernan, who was waiting to welcome her father home. Apollo 17 splashed down on 19 December 1972. Within days of its return, US National Public Radio carried an interview with a farmer from Ohio who said, ‘I don’t think they went to the Moon.’ Since then no one has left low Earth orbit.
Apollo 17 brought back 111 kg of lunar samples. One of them is particularly cherished by geologists. It is a 1-m-long tube of regolith taken from a deep drilling. It is kept as a reserve sample and has never been opened.