Lecture 3

Apollo 17 astronaut Eugene Cernan on the Moon - NASA image AS17-140-21391

Apollo on the Moon

Project Apollo was an attempt by the United States to recover lost ground and gain the upper hand in a technological confrontation with the Soviet Union. The goal was set in 1961, and accomplished with the first Moon landing in 1969. After five more landings the program was terminated and less expensive space goals were pursued for the next four decades. Only now is a return to the Moon being planned.
Apollo missions (lower down the page: click each Apollo mission name in the list)
Apollo missions
Apollo memories
The decision to go to the Moon
Apollo Lunar Surface Journal - transcripts of the mission communications.

Landing sites

Landing site selection was a major undertaking. The Moon is a big place. Where should a crew land? The sites had to be safe - gentle slopes, few small craters, not many rocks. Sites like that could not be chosen using telescopes. Spacecraft near the Moon were needed to see it close up. The Ranger spacecraft gave a first closeup look, and the Lunar Orbiters thoroughly examined potential sites. The Surveyor landers showed what some sites looked like from the surface. A committee, The Apollo Site Selection Board, worked for several years to choose sites. The early sites were very safe, smooth and flat, the later sites more visually appealing and scientifically interesting. Taken together they allowed samples to be collected from different types of rock, and of different ages, so the Moon's geology and history could be understood better.
Landing sites - zoom in
Project Ranger
Ranger images
Surveyor missions
Lunar Orbiters
Lunar Orbiter images
LRO Quickmap

Sequence of Apollo flights

Apollo was developed step by step in a very logical manner. First, equipment was tested on the ground. Then, several Apollo spacecraft flew in Earth orbit without a crew to test the new vehicle. One crew, referred to now as Apollo 1, died during a ground test at the Kennedy Space Center. When everything had been tested, the first Apollo crew to fly took Apollo 7 into Earth orbit. Then, in a huge leap, the second Apollo crew to fly took Apollo 8 all the way to the Moon and back. Apollo 9 stayed in Earth orbit for a test flight of the Moon landing vehicle (Lunar Module). Then Apollo 10 flew the Lunar Module in orbit around the Moon, testing every part of the system except the landing itself. Finally, Apollo 11 landed. Six more Apollo flights were made. All except Apollo 13 landed safely. Each Apollo went one step beyond the one before, with more time on the surface, more samples collected, and more distance covered in more interesting landing places.
Apollo missions
Apollo 1 accident

Apollo 8

The Apollo 8 crew were the first humans to leave Earth and travel to another world, but they did not land on the Moon. The mission was designed to test the spacecraft, the navigation and communication systems, and the ground control systems. Apollo 8 orbited the Moon in December 1968 and returned safely to Earth. It did not carry a Lunar Module, but its crew photographed the Moon close up, including dramatic images of Earth rising over the lunar horizon.
Apollo 8
Apollo 8 images

Apollo 10

Apollo 10 was a full system test in lunar orbit, including a Lunar Module (LM) which was flown separately from the main Apollo spacecraft (the Command/Service Module, CSM). The LM was flown down to only about 15 km above the surface, but did not land. Apollo 10's crew took close-up images of the Apollo 11 landing site and many other areas.
Apollo 10
Apollo 10 images

Apollo 11 - the first human landing on another world

This flight in July 1969 fulfilled President Kennedy's challenge. The landing site was a very smooth part of the 'Sea of Tranquility' (Mare Tranquillitatis). It was chosen just to be as safe as possible. Two people, Neil Armstrong and Edwin 'Buzz' Aldrin, landed on the Moon and walked on its surface for about 3 hours. They set out instruments including a seismometer, collected rock samples, and then returned safely to Earth. A third crew member, Michael Collins, stayed in lunar orbit and photographed the lunar surface. Most of the rocks collected were pieces of basalt lava flows, 3.6 billion years old.
Apollo 11
Apollo 11 images
Apollo 11 landing site
View from the window
Surface of the Moon
LM on the surface
Deploying the seismometer
Carrying equipment
LM and landing area
Apollo 11 site seen from orbit

Apollo 12

Apollo 11 could have landed anywhere as long as it landed and returned safely. Future exploration required pinpoint landings, so the crew would be within walking distance of their scientific targets. Apollo 12 tested the ability to make a pinpoint landing, using as its target the Surveyor 3 spacecraft, which had landed nearly three years earlier. How did engineering materials like plastic, aluminum, paint or glass stand up to the extremes of the lunar environment? Pieces of Surveyor 3 would be collected and returned to Earth to find out. This landing site was in the 'Ocean of Storms' (Oceanus Procellarum), in an area now called 'Sea of Islands' (Mare Insularum). The mission was very successful, and the Surveyor samples were collected as planned. A science station called ALSEP (Apollo Lunar Surface Experiment Package) was set up during one EVA (extra-vehicular activity, 'moonwalk') and operated for 8 years. A second EVA allowed the astronauts to collect samples from several craters and from Surveyor 3. The rocks collected at this site were different from those at Apollo 11 - younger and with different composition. They were also basalt lavas, but only 3.2 billion years old. Some grey soil at the site might have been thrown out of the large crater Copernicus 1 billion years ago.
Apollo 12
Landing site
Apollo 12 images
On the surface
Unloading equipment
Setting up the ALSEP
Looking into Surveyor crater
Approaching Surveyor
Surveyor 3
Apollo 12 site seen from orbit

Apollo 13

Apollo 13 was supposed to land in a hilly area very different from the earlier sites. An explosion in an oxygen tank in the Service Module during the long flight to the Moon prevented a landing and almost killed the crew, but by exercising great ingenuity they were able to bring the damaged spacecraft home safely. They did obtain a few images of the Moon as they looped around it. The scientifically desirable landing site was visited by Apollo 14 instead.
Apollo 13
Apollo 13 images

Apollo 14

Apollo 14 completed the tasks originally intended for Apollo 13. The landing site was a hilly area (the Fra Mauro hills) made of debris thrown out of a gigantic impact (the Imbrium basin) hundreds of kilometres further north. A small fresh crater called Cone had excavated that debris from under any later material thrown in by other impacts. The crew landed safely and made two EVAs, set up another ALSEP, and walked up the hill to Cone crater to collect rock samples. The impact debris was about 3.85 billion years old, older than the lava flows samples at the earlier landing sites.
Apollo 14
Landing site
Apollo 14 images
First steps on the surface
Hilly landing site
ALSEP deployment
LM from ALSEP site
Rocks at Cone crater's rim
Apollo 14 site seen from orbit

Apollo 15

Apollo 15 was the first of a new generation of Apollo missions with increased capabilities. The crew landed at a spectacular site called Hadley-Apennine, between a mountain range (the 'Apennine Mountains', Montes Apenninus) and a deep winding valley ('Hadley Rille', or Rima Hadley) cut by flowing lava. They made three EVAs, using an electric vehicle to cover much more distance than walking would allow. First they set up an ALSEP, then visited the foot of the mountain range to collect rocks. On the second EVA they returned to the mountains for more geological work. On the third EVA they visited the edge of the valley, photographing layered rocks on the far wall and gathering samples. Time ran out, preventing a visit to nearby hills suspected of being volcanic. The mountains were part of the giant Imbrium Basin, the same huge crater whose debris deposits were visited by Apollo 14. The lava plains at their feet, and the valley, were younger. The orbiting Command-Service Module carried new cameras and other instruments for lunar mapping.
Apollo 15
Landing site
Apollo 15 images
On the surface near the LM
Working with the LRV
Looking along Hadley Rille
Mount Hadley
Obligatory flag shot
LM from a distance
Rocky wall of Hadley Rille
Apollo 15 site seen from orbit

Apollo 16

Apollo 16 went to a completely different type of site. The Moon has dark lava plains and bright highlands covered with big craters, easily visible to us even without a telescope. Apollo 16 landed in the highlands, the only Apollo to do so. Its landing site was named Descartes, after a nearby crater. The place was chosen because geologists thought it might be covered with bright volcanic materials, quite different from the dark lavas seen at earlier sites. This was a mistake. All Apollo 16 rocks were debris from large impacts, like the Apollo 14 samples. Apollo 16 also had a rover and made three EVAs like Apollo 15. On EVA 1 the crew set up an ALSEP and a small ultraviolet telescope, and examined the area near the landing site. EVA 2 was a trip to a nearby hill called Stone Mountain. On EVA 3 the crew drove north to a fresh crater called North Ray, and took samples from a house-sized boulder on its rim. The Apollo 16 samples showed that the highlands contain little or no volcanic material.
Apollo 16
Landing site
Apollo 16 images
Working at the ALSEP
Craters on EVA 1
Stone Mountain from the landing area
Small telescope in LM shadow
The view from Stone Mountain
North Ray crater
Apollo 16 site seen from orbit

Apollo 17

The last Apollo was the only one to carry a professional scientist. All other lunar astronauts had been military or test pilots who learned some geology. Harrison Schmitt was a geologist who learned to be a pilot and astronaut. The landing site was a spectacular valley between mountains on the edge of another giant impact basin called Serentitatis. The valley was called Taurus-Littrow, after the Taurus Mountains and Littrow, a nearby crater. The valley floor was unusually dark, and was thought to be quite young in lunar terms, with several small volcanic hills. In fact the dark material was quite old volcanic ash, and the only 'volcanic hill' they visited was just an ordinary impact crater. Despite this, important aspects of lunar geological history were explored by the crew. on EVA 1 they set up the last ALSEP. On EVA 2 they made the longest drive of the Apollo program, collecting debris from a landslide on one of the mountains, and volcanic ash dug up by a small impact crater. On EVA 3 they drove across the valley to the other side and sampled large rocks which had rolled down from the upper slopes.
Apollo 17
Landing site
Apollo 17 images
On the surface
View from LM window
Rover and valley floor
Setting up equipment
At the foot of the mountain
Mountains and rover tracks
Working at North Massif
Schmitt at Split Rock
Apollo 17 site seen from orbit

Conclusion

Between them, the six Apollo landings collected many different types of rock, thousands of images and many other types of data. They revolutionized our understanding of the Moon and of Earth's early history. Not bad for a program that originally had nothing to do with science.

Apollo 17 astronaut Eugene Cernan on the Moon - NASA image AS17-140-21391