Apollo 12

Launch, orbit & landing data: Designation  04225 / 69099A Launch date - time  14 Nov 1969 - 16:22:00 UT Launch site  KSC, LC39A Launch vehicle  Saturn V (SA-507) Payload  Apollo CSM 108 Size (m)  11.15 long - 3.91 dia Mass at launch(kg)  43953 (CM/SM/LM) Mass empty (kg)  11250 Flight Crew  Conrad, Charles (CDR) Gordon, Richard (CMP) Bean, Alan (LMP) Call Sign  Yankee Clipper/Intrepid Backup crew  Irwin, Scott, Worden Earth orbit on Nov 14 (16:49 UT):    - Perigee / Apogee  183 / 199 km    - Inclination  32.56°    - Period  88.15 min Orbital parameters on 14 Nov (21:36 UT):    - Perigee / Apogee  208 / 439210 km    - Inclination  33.2°    - Period  18150 min Selenocentric orbit on 18 Nov (03:50 UT): Landing date - time  24 Nov 1969 - 20:58:25 UT Landing location  15° S, 165° W 735 km southeast of Pogo-Islands in Pacific Ocean Prime recovery ship  U.S.S. hornet Flight Duration (d:hr:min)  10:04:36 (244h 36min 25sec) Nbr Earth orbits  1,5 Nbr lunar orbits

Crew:

Flight:

LM on Moon with Surveyor - Credit: NASA.

Official NASA Account of the Mission from Where No Man Has Gone Before: A History of Apollo Lunar Exploration Missions, by W. David Compton, published as NASA SP-4214 in the NASA History Series, 1989.

Charles Conrad, Richard Gordon and Alan Bean, on his way to the rocket. Credit Associated Press

Apollo 12 Lunar Module in Shop - Credit: NASA.

Surveyor 3 with astronaut; Apollo 12 Lunar Module in the background - Credit: NASA.

The only midcourse correction maneuver of the outbound flight was performed the next day, a 9.2-second burn that put the spacecraft on a fuel - saving hybrid trajectory. For the rest of the uneventful three-and-a-half-day trip to lunar orbit, the crew spent their time housekeeping, tending to spacecraft systems, and observing the earth and the moon.

Arriving at the moon 83 1/2 hours after liftoff, Conrad fired the main propulsion engine for almost 6 minutes to go into an elliptical lunar orbit. Five hours later a second burn put the spacecraft into a circular orbit at 60 nautical miles (111 kilometers) altitude, where Yankee Clipper would stay until it was time to return to earth. The spacecraft passed over and photographed Apollo 13's landing area in the Fra Mauro formation, and on the tenth revolution Conrad notified Capcom Gerald Carr that "you can tell good Captain Shaky [Jim Lovell, commander of Apollo 13] that he can relax. We've got his pictures."

Surveyor 3 / Apollo 12 Artists Concept - Credit: NASA.

For the next several hours Conrad and Bean in Intrepidand Gordon in Yankee Clipper were busy setting up their guidance and navigation computers and exchanging data with the ground. When all was ready, Gordon turned the spacecraft so that the long axis of the command and service module was perpendicular to the flight path with the lunar module outward from the moon, retracted the docking latches, and fired his attitude-control thrusters to move Yankee Clipper away from Intrepid. The landing craft was 5 miles (8 kilometers) north of its intended ground track - largely as a result of an error in the landing site location and the inability to adequately correct for the moon's irregular gravity field. This and other errors would be removed by the instructions transmitted to the guidance computer after the lunar module headed down for its landing.

A lonely Surveyor 3 on Lunar Surface; Apollo 12 LM in the distance. - Credit: NASA.

After seven minutes Intrepidnosed over into a near-upright position and for the first time Conrad could see the lunar surface. The principal landmark identifying his landing point was a pattern of craters the astronauts called "Snowman"; Surveyor III lay halfway up the eastern wall of the crater that was the Snowman's torso, and Intrepid was targeted for the center of the crater. As soon as he could see out the window, Conrad cried delightedly, "Hey, there it is [Snowman]! There it is! Son of a gun! Right down the middle of the road!" Then, as Bean called out altitude, velocity, and quantity of fuel remaining; Conrad maneuvered the craft with his hand controller to pick a smooth spot to land on. The engine exhaust began kicking up dust about a hundred feet (30 meters) above the surface and by the time Intrepid reached 50 feet ( 15 meters) the cloud obscured the surface completely. At 1:54:36 a.m. EST on November 20, Pete Conrad made a blind landing - exactly where, he could not tell, but certainly close to the intended spot.

Surveyor 3 as photographed by the crew of Apollo 12 - Credit: NASA.

After postlanding checks of systems, Conrad and Bean described what they could see from their spacecraft. Intrepidhad landed in undulating terrain pocked with craters ranging from a few feet to several hundred feet across, the larger ones rimmed by large blocks of rock. Numerous boulders, up to 20 feet (6 meters) in size, were scattered around the site, most of them angular rather than rounded, many showing fillets of dust around the base. Immediately in front of the landing craft Bean saw an area of "patterned ground" - parallel cracks in the surface soil perhaps an eighth of an inch (3 millimeters) deep. From the lunar module the crew could distinguish no color differences in the rocks or soil; everything seemed the same bright white. Five and a half hours after landing, Conrad squeezed out the hatch, then clambered down the ladder to the bottom rung. As he stepped off onto the landing pad Conrad remarked, "Man, that [step] may have been a small one for Neil, but that's a long one for me." Looking around, he spotted the Surveyor halfway up the opposite wall of the crater. One of the first things Conrad noticed was that he was going to get extremely dirty: the surface dust was finer and deeper than he had expected.

Surveyor 3 / Apollo 12 Artists Concept - Credit: NASA.

The primary objective of their first excursion was to deploy the scientific experiments. Conrad and Bean unloaded the package easily, picked a spot 130 meters (425 feet) northwest of the lander, and laid out the instruments without any serious difficulty. On their way back to Intrepidthey picked up more documented samples and Bean took a soil sample with the core tube. After nearly four hours on the surface, the astronauts returned to the lunar module, dusted each other off as best they could without brush or vacuum cleaner, and climbed back inside. After a brief evaluation of the day's work and some discussion of the next day's plans, Houston signed off and the two astronauts strung up their hammocks and turned in.

Apollo 12 Lunar Module in Shop - Credit: NASA.

During the next four hours Bean and Conrad covered something more than one kilometer (3,300 feet), following a large-scale photographic map prepared for the traverse and chatting constantly with each other and with Houston. Scientists in Houston followed their progress from their references to the maps they carried. The extensive conversation was intended to substitute for a geologist's field notes. On the nearly featureless lunar surface, sampling proved somewhat difficult; except for size, most of the rocks showed few distinguishing features. Colors and textures were not always easy to determine, and when they were, the astronauts tended to use nonscientific terms in describing them - probably a symptom of their sensitivity to possible misuse of geological terminology. At one point Conrad noted a rock containing a "ginger-ale-bottle green" crystal (which was probably olivine), and a few minutes later Bean spotted a rock he said "looks almost like a granite," but immediately added, "of course it probably isn't, but it has the same sort of texture." Bean and Conrad documented their samples carefully, photographing many of them and describing the location and bag number for later reference. At "Head" crater, following instructions from Houston, Conrad dislodged a medium-sized rock and allowed it to roll down the slope to determine whether the seismometer some 70 meters (230 feet) away could detect it (it did). Then it was on to "Bench" and "Sharp" craters, where they sampled several large rocks on the surface that might be bedrock thrown out when the craters were formed.

A lonely Surveyor 3 on Lunar Surface; Apollo 12 LM in the distance. - Credit: NASA.

Examination of the Surveyor, the only human artifact ever encountered in lunar exploration, was among the more interesting parts of the mission for Conrad and Bean. What they noticed first was that much of its originally white surface had turned brown - a change they attributed to a deposit of dust when they found it could be wiped off. After photographing the surrounding surface and examining the spacecraft, they removed the Surveyor's television camera and cut off pieces of electrical cable and structural tubing for study by scientists at the Jet Propulsion Laboratory. They decided to remove the trenching scoop as well; then, after collecting soil samples, they headed for another small crater to take a few more samples on their way back to the lunar module.

Surveyor 3 as photographed by the crew of Apollo 12 - Credit: NASA.

Despite the fact that they had trebled the existing record for lunar surface activity, Bean and Conrad were not exhausted and had expended about 10 percent less energy than anticipated. Both returned to the lunar module with almost 40 percent of their oxygen supply remaining on both excursions. Bean suggested to the medical officers that he would have enjoyed an occasional drink of water while working on the surface; not that he felt dehydrated, but he would have been more comfortable if he had been able to relieve the dryness in his mouth.

Intrepid's ascent stage lifted off the moon on time, and an hour and a half later Conrad had Yankee Clipper in sight. Back in lunar orbit the dust the lunar explorers had brought in with them began to float, thick enough to be visible in the cabin. After the two spacecraft had docked they attempted to vacuum up the dust, with little success, so they removed and packaged their suits in the lunar module, hoping to minimize contamination of the command module. In spite of their efforts, considerable dust clung to everything they brought back and remained suspended in the atmosphere; the environmental control system seemed not to filter it out as completely as had been expected.

Surveyor 3 with astronaut; Apollo 12 Lunar Module in the background - Credit: NASA.

Yankee Clipper stayed in lunar orbit for 11 more revolutions, finishing up the "bootstrap" photography and landmark tracking, looking at sites being considered for Apollo 14 and 15. Then the crew boosted their spacecraft out of lunar orbit and settled in for the three-day voyage home. Now and then they chatted with the duty CapCom about something that crossed their minds concerning their exploration. Once in a while scientists wanted to debrief them concerning details of their lunar surface activity. For most of the time, however, they relaxed.

At one point both Conrad and Bean passed along some reservations they had about the field geology exercise. They had found the lunar surface a particularly difficult one for classical field-geological techniques. Bean commented,

... we talked with [the geologists], before we went, about [the fact that] the main objectives of the geology wasn't to go out and grab a few rocks and take some pictures, but to try to understand the morphology and the stratigraphy... of the vicinity you were in. Look around and try to use your head along those lines. Well, I'll tell you, there [were] less than ten times I stood in spots... and said, "Okay now, Bean,... is it possible to look out there and try to determine... which is first, which is second, and all that?"... That whole area has been acted on by these meteoroids or something else so that all these features that are normally neat clues to you on earth are not available for observation.

Conrad concurred: "I think even a trained geologist would have trouble doing a whole lot of field geology that way on the moon." Long afterward, Bean still felt that astronauts could be most effective on the lunar surface by selecting and documenting as many apparently different kinds of samples as possible rather than attempting on-the-spot geologizing. During a press conference on the last day out, Conrad was asked whether he thought it would be desirable to have a geologist as a member of the crew. He did indeed think so, but pointed out that landing Intrepidhad required all the piloting skill he had - implicitly echoing Deke Slayton's contention that landing on the moon was not yet a job for a novice.

Early on the morning of November 24 Apollo 12 splashed down some 600 kilometers (375 miles) east of Pago Pago, 3.5 kilometers (2 miles) from the recovery ship U.S.S. Hornet. The landing was rough - apparently Yankee Clipper hit a rising wave as it swung on its parachutes - hard enough to dislodge a 16-mm movie camera from its bracket and slant it into Alan Bean's forehead, momentarily stunning him and opening a 1-inch (2.5-centimeter) cut, which Conrad bandaged.

The recovery swimmers soon arrived, tossed respirators and coveralls - replacing the biological isolation garments that the Apollo 11 crew had found so objectionable - into the command module, then assisted the astronauts into the raft. Half an how later recovery helicopters set the crew down aboard the Hornet and they went straight to their mobile quarantine facility. Lunar sample containers and film magazines were removed and flown to Pago Pago and thence to Houston. The astronauts had a longer journey: four days aboard ship to Hawaii, then a nine-hour flight to Houston. On the morning of November 29, Conrad, Bean, and Gordon entered the Lunar Receiving Laboratory for their 11-day stay in quarantine.

That Apollo 12 was a success was apparent even on preliminary evaluation. The procedural changes incorporated to improve landing accuracy had allowed Conrad to put Intrepid down within sight of Surveyor III , exactly as intended. Lunar exploration had been easy; neither Bean nor Conrad encountered any unexpected difficulties and both had oxygen to spare when they returned. And while they had found it hard to apply their field - geology training on the unrevealing surface of Oceanus Procellarum, they had collected nearly 75 pounds (34 kilograms) of samples, most of them documented. The surface experiments they had set up were returning streams of data, and scientists agreed the astronauts had done a remarkable job. Communication between scientists in Houston and the astronauts on the moon had been well handled by Mission Control. If Apollo 12 was a reliable indicator, the scientific return from the remaining eight missions should be gratifying.

External links:

• AmericaSpace: 201114-Remembering Apollo 12′s Hair-Raising Launch