Apol­lo 12: Des­ti­na­tion Ocean of Storms - 2nd Lu­nar Land­ing

Charles 'Pete' Conrad examines the lunar probe Surveyor 3
Charles 'Pe­te' Con­rad ex­am­ines the lu­nar probe Sur­vey­or 3
Image 1/2, Credit: NASA

Charles 'Pete' Conrad examines the lunar probe Surveyor 3

On 19 Novem­ber 1969, as­tro­nauts Charles Con­rad (im­age) and Alan Bean land­ed in the im­me­di­ate vicin­i­ty of the robot­ic Sur­vey­or 3 space­craft, which had stood in the Ocean of Storms since 20 April 1967, act­ing as a pre­cur­sor to the Apol­lo mis­sions. The pre­ci­sion land­ing was one of NASA’s pre­con­di­tions for con­tin­u­ing with the pro­gramme. In the back­ground is the lu­nar mod­ule 'In­trepid' of the Apol­lo 12 mis­sion.
Alan Bean takes a sample of lunar soil
Alan Bean takes a sam­ple of lu­nar soil
Image 2/2, Credit: NASA

Alan Bean takes a sample of lunar soil

Here, Apol­lo 12 Lu­nar Mod­ule Pi­lot Alan Bean fills a sam­ple con­tain­er with lu­nar soil. At­tached to his chest is one of the cam­eras used to take the many pho­tographs that brought the Moon clos­er to peo­ple back on Earth.

Crew and spacecraft

After the splendid success of the first lunar landing of Apollo 11 in July 1969, NASA was ordered by the US government to ‘step on the brake’: in fall of that same year, the Apollo budget was cut and the program restricted to nine (this was the figure then envisaged) missions and no more than two Moon flights per year. In the following year, it was even decided that Apollo 17 would be the last to land on the Moon. At least, this permitted further improvements of the spacecraft and the astronauts’ equipment.

Despite all this, NASA, still euphoric about Apollo 11, worked with unabated vigor to prepare the second lunar landing that was scheduled for November 1969. Apollo 12 was to be the first of three initially planned ‘H-missions’ whose objective it was not only to land on the Moon and return to Earth as quickly as possible but to remain on the lunar surface for a somewhat longer stay. Similarly, the scope and complexity of the experiments and geological studies was to be increased. A Saturn V rocket bearing the serial number SA-507 was prepared for launch. The spacecraft and the lunar module were almost identical in construction with those of Apollo 11.

The Commander was to be Charles ‘Pete’ Conrad, an experienced pilot who was highly regarded in the astronauts corps and who had been in space twice before, on Gemini V and Gemini XI. Alan Bean was assigned as Lunar Module Pilot, and Conrad‘s companion on Gemini XI, Richard ‘Dick’ Gordon, was nominated as Command Module Pilot. It was Bean’s first flight into space. If the first attempt to land on the Moon had failed, Charles Conrad would probably have been the first man on the Moon unless something went very wrong with Apollo 11.

Now, Apollo 12 was intended to demonstrate that it was even possible to make a precise, almost pinpoint landing on the Moon. The target was to come down about 1,400 kilometers further west than Apollo 11, in the immediate vicinity of the robotic space probe Surveyor III which had landed on the Moon on April 20, 1967. The lunar module was named Intrepid for ‘fearless’ or ‘brave’ and the spacecraft was given the name Yankee Clipper, first in order to pay tribute to the professional career of the three astronauts in the navy by invoking the image of a rakish wind-jammer, and second because commander Charles Conrad actually was a dyed-in-the-wool east coast Yankee.

Mission progress

The kick-off of Apollo 12 was far more exciting than that of Apollo 11. Two days before lift-off, a leak was discovered in one of the oxygen tanks of the service module. A replacement tank had to be removed from the service module intended for Apollo 13 and installed in the rocket that was already waiting on the launch pad. On November 14, 1969, at 11:22 local time, the rocket lifted off despite the thunderstorm that had begun moving across Cape Kennedy during the countdown. The rocket was promptly struck by lightning twice, 36 and 52 seconds after lift-off, temporarily causing the entire onboard electronics to fail.

Flight controller John Aaron suspected what had happened, having observed an anomaly during a simulation one year before when a voltage drop had caused the on-board electronics to break down. When he told flight director Gerry Griffin of his recommendation “Flight, try SCE to ‘AUX’”, the latter had no idea what he was talking about. When Conrad was given this instruction, he asked, “What the hell is that?” Luckily, Alan Bean knew where the SCE switch was. He set it to ‘AUX’ – and in the same instant, telemetry returned, the mission could be continued and an abort averted.

Later, both the injection into a transfer path to the Moon and the deceleration into an orbit about 110 kilometers above its equator on November 17 went without a hitch. To make sure that the lunar module had not suffered any lightning damage, Conrad and Bean entered Intrepid somewhat ahead of time to check the systems. On November 19 at 4:17 CET, they undocked from the mother ship and, like Apollo 11 before them, flew from east to west along the equator to approach their destination, the vast plains of Oceanus Procellarum, the ‘Ocean of Storms’, in the western part of the near side of the Moon.

During the automated approach, Conrad and Bean peered through the lunar module’s small windows in an attempt to locate a characteristic pattern of craters in the target area which resembled a snowman when viewed from the east. When they discovered the ‘snowman’, Conrad switched as planned to manual control for the last 400 feet (122 meters) of the descent, sought out a suitable spot directly next to the snowman’s ‘head’, and landed Intrepid safely on the Moon on November 19, 1969 at 7:54 and 36 seconds CET despite the clouds of dust raised by the engine, which obscured his vision completely.

On the Moon

Passing over the site for the second time, Richard Gordon discerned both Intrepid and the robotic probe Surveyor III from his 110-kilomter orbit. Using a sextant, Gordon was able to determine the position of the lunar module fairly precisely. For Houston, this confirmed that the crew had actually succeeded in making a pinpoint landing. Well aware that, this being the second landing on the Moon, the first words spoken after leaving the lunar module would not be accorded the same importance as Neil Armstrong‘s “small step”, Pete Conrad said when he set foot on the surface of the Moon on November 19, 1969, at 12:44 CET, “Whoopie! Man, that may have been a small one for Neil, but that’s a long one for me”, alluding to his small stature.

Alan Bean followed soon afterwards in the best of moods. The atmosphere was much more relaxed than during the first lunar landing, and activities were accompanied by a great deal of humor. When a television camera was switched on, its light-sensitive tube was dazzled and destroyed because it was directed unprotected into the sunlight for a short moment – the scheduled color-TV transmission had to be cancelled. This time, the American flag was planted at a greater distance from the lunar module, for the one set-up by Apollo 11 had been toppled over by the rocket-engine stream during the return lift-off. The American flag in the (Moon) dust – never again!

This second lunar landing revolved around science. A voluminous package of physical experiments called ALSEP (Apollo Lunar Surface Experiment Package) was installed for the purpose. When Alan Bean had to free ALSEP‘s jammed radioisotope battery from its bracket with a few firm hammer blows, he quipped, “Never fly to the Moon without a hammer…!” After an EVA of four and a half hours and no more than four hours of sleep, preparations for the second excursion began. At seven stations distributed over a distance of 1300 meters, several tasks were done that were mainly concerned with collecting rock and soil samples. The crew was in good physical condition, heart rates never reached critical heights. The high point was a walk to Surveyor III which stood 163 meters away from Intrepid on the sloping interior wall of a crater. The astronauts removed a camera and some metal parts for examination on Earth and returned to their lunar module, forgetting to take with them a number of magazines containing exposed film that remain on the Moon to this day.

Results

On November 20 at 15:25 CET, Intrepid lifted off on schedule, docking to Yankee Clipper a few hours later. On November 24, Apollo 12 returned from space after ten days and four and a half hours. Once again, the second crew to have been on and near the Moon had to undergo quarantine to ensure that they did not pick up any unknown pathogens on the Moon. The mission was a great success. First, for the engineers, because they had proven that it was possible to make a pinpoint landing on the Moon. This encouraged NASA to go for targets in later missions that were not situated in a dead flat plain. Second, it was a success for science, because in the nearly eight hours for which the lunar excursions lasted many more experiments had been carried out and more samples gathered, 34.3 kilograms in all.

Geologists, however, would have preferred a region further south, in the Flamsteed crater, a suggestion which had also been discussed before the mission. The low number of impact craters indicated that some of the most recent volcanic deposits are exposed there. With samples from Flamsteed, the period of volcanism on the Moon might have been fixed more precisely, particularly the end of the eruptions about three billion years ago. The geology exposed at the landing site of Apollo 12 resembles that found by Apollo 11, although volcanism there is younger by about 500 million years. Moreover, it was found that the basalt samples taken by Apollo12 from this western ‘Mare’ clearly differ in their mineralogy from those taken by Apollo 11 farther east.

All this means that, contrary to assumptions, the formation of molten rock – magma – in the interior of the Moon was quite a complex process, that volcanism on the Moon, which is four and a half billion years old, was not restricted to a brief episode, and that it was not triggered by the impact of enormous asteroids about four billion years ago. Of equal interest were samples of greenish glass: since the Moon has no atmosphere, infinitesimally small dust particles from the Solar System have been bombarding its surface at very-high speed from the very beginning, gradually grinding down rocks into a kind of dust called regolith which is as fine as cement, and generating enough heat in the process for the dust to melt and promptly solidify again into glass.

The texts presented here were created by the DLR Institute of Planetary Research and space expert Gerhard Daum for the exhibition ‘Apollo and Beyond’ at the Technik Museum Speyer. Among other things, the history of the Apollo programme is showcased in detail using both text and images. In addition, full-scale models of the Apollo 11 Lunar Module ‘Eagle’, the Apollo 15 Lunar Roving Vehicle and an Apollo space suit for visiting the Moon’s surface, as well as a 3.4-billion-year-old rock collected from the Apollo 15 landing site can be seen in a lunar landscape.

Contact
  • Ulrich Köhler
    Ger­man Aerospace Cen­ter (DLR)
    In­sti­tute of Plan­e­tary Re­search
    Rutherfordstraße 2
    12489 Berlin
    Contact
  • Elke Heinemann
    Ger­man Aerospace Cen­ter (DLR)

    Com­mu­ni­ca­tions and Me­dia Re­la­tions
    Telephone: +49 2203 601-2867
    Linder Höhe
    51147 Cologne
    Contact
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