From the Apollo Lunar Surface Journal. Reproduced with the permission of Journal editor Eric M. Jones
Table of Contents
- Mission Profile
- The End of the Beginning
- ALSEP Deployment
- The Little Old Fendermaker
- Hole-in-the-Wall and South Massif
- The Scarp Gravimeter Stop
- Ballet Crater and the Comedy of Errors
- "There is Orange Soil!!"
- Camelot Crater
- The Last Apollo EVA on the Moon
- Tracy's Rock
- Dikelets in the Station 7 Boulder
- The Sculptured Hills
- The Puzzle of Van Serg
- The Final Close-out
- Some Thoughts About Mission Planning
- Launched: December 7, 1972
- Landed on the Moon: December 11, 1972
- Landing Site: Taurus-Littrow
- Returned to Earth: December 19, 1972
- Command Module: America
- Lunar Module: Challenger
Eugene A. Cernan, commander
Ronald B. Evans, command module pilot
Harrison H. Schmitt, lunar module pilot
- Launch of Apollo 17.
- Lunar Module passes over Taurus-Littrow landing site.
- Lunar Module landing.
- Astronaut struggles with equipment, falls over.
- Astronauts play soccer with rock.
- Astronaut drops sack, falls down. "Dad Gum It!".
- "Orange soil!".
- Jumping astronaut. "By golly time goes fast...".
- Blast off of Lunar Module.
- Lunar Module approaches the Command Module.
- Space walk.
- Crescent moon.
- Apollo 17 splashdown.
- Apollo 17 slide show.
And, to explore all of this, Deke Slayton had picked a two-man crew with, perhaps, the broadest range of capabilities of any of the Apollo crews. Commander Gene Cernan was a veteran of two prior missions - having flown with Tom Stafford on Gemini IX and with Stafford and John Young on Apollo 10. He was the only LM Commander to have flown a mission as Lunar Module Pilot and there were few in the astronaut corps who knew the spacecraft as thoroughly. And Lunar Module Pilot Jack Schmitt not only knew the LM but was also a professional geologist who, as we have seen throughout the previous chapters, was an active participant in the planning that had gone into the prior missions. If Taurus-Littrow was a geologist's paradise, them Jack Schmitt was the geologist.
Three of the new experiments figured prominently in the Apollo 17 geology traverses. One of these was an array of geophones designed to detect seismic waves generated by small explosive charges which Schmitt and Cernan later placed at predetermined spots as they drove around the valley doing geology. Detonation of the charges was commanded remotely from Earth after the crew was safely back in orbit. Analysis of the resulting data provided information about the subsurface structure of the valley.
The other two other pieces of new equipment were also designed to provide information about the subsurface structure: a portable "traverse" gravimeter (the TGE) and a surface electrical properties (SEP) experiment.
The traverse gravimeter was a simple experiment. The instrument, itself, was a battery-powered, stand-alone device packed into a closed, 6x6x12 inch box. At each of the geology stops, Cernan took the instrument off the Rover, set it on the ground, pushed a button to start the measurement and then left it alone while he took care of other chores. After about three minutes, the measurement was finished and, when he had a moment free from other tasks, Cernan pushed the "Read" button, read a string of numbers to Houston, and then put the gravimeter back on the Rover. Each of the measurements was a determination of the local pull of gravity; and variations in the measurements could be interpreted as variations in the density of the rocks below the surface. It was a simple, valuable experiment that took only a little time for a large return; and the only significant problem that Cernan had with the instrument was that of getting low enough to set it on the ground and punch the buttons. A taller instrument would have helped and, indeed, several measurements were taken with the gravimeter on the Rover. On such occasions, both astronauts had to make sure that neither of them touched the Rover before the measurement was done.
In principle, the SEP was also a simple experiment requiring little expenditure of crew time. At the end of the first EVA, Cernan used the Rover to draw a couple of perpendicular tracks upon which he and Schmitt then laid out antenna wires for the SEP's radio-frequency transmitter. There was a receiver/recorder mounted on the Rover and, while Cernan and Schmitt were out on their second and third geology traverses, the equipment on the Rover picked up signals from the transmitter. Those signals were influenced by variations in the electrical conductivity of the subsurface rocks between the Rover and the transmitter and, therefore, contained structural information. Unfortunately, at some point during the first EVA, the glue on a patch of Velcro holding down a dust cover on the SEP recorder failed. Cernan and Schmitt attempted to tape the cover shut but the tape didn't stick well to the dust-impregnated cloth and the instrument got fairly dirty. The SEP recorder was equipped with a mirror-like radiator which was exposed to the black lunar sky during each of the rest periods and at each of the geology stops; and, had the mirror been clean and had the instrument not been quite so temperature sensitive, the radiator would have cooled the instrument enough to keep it running through all of the geology traverses. However, despite Cernan's best dusting efforts, the radiator was too dirty - and the receiver too temperature sensitive - to work properly. The instrument overheated and failed, returning relatively little useful information and taking up far too much crew time in the process.
The SEP problems emerged on Day 2, and were part of a series of minor frustrations in an otherwise very successful and productive mission. According to the mission operations plan, deployment of Rover and of the ALSEP was to have taken a total of four hours, leaving Cernan and Schmitt time for a 90-minute geology trip south from the LM to Emory Crater. However, through no fault of his own, Cernan had a great deal of trouble removing the deep core, despite the fact that he had a treadle and jack identical to the one Charlie Duke had used successfully on Apollo 16. The soil at Taurus-Littrow simply gripped the core very tightly and the effort of removing the core cost both time and oxygen. As a result of Cernan's troubles with the core - and to Jack Schmitt's considerable consternation - the first day's geology trip had to be shortened to an hour.
There were also problems with the gravity wave detector, a potential Nobel Prize experiment. Gravity waves were a predicted consequence of Einstein's theory of General Relativity and a confirmed discovery would have been a major achievement. In essence, the Apollo 17 experiment consisted of a delicate balance beam designed to respond if a passing gravity wave caused the Moon to oscillate. Seismically, the Moon is very quiet compared with the Earth. The moon does have quakes, but they are relatively infrequent and, a lunar gravity-wave detection coupled with a nearly simultaneous detection by instruments on Earth would have been a momentous event. During the trip out from Earth, the balance beam had been locked ("caged") and, once Schmitt deployed the instrument and had it more or less level, he uncaged the beam. Because it would have been impractical for Schmitt to level the instrument precisely, the experimenters then did some fine-tuning by adjusting the mass distribution on the balance beam. Or, at least, they tried. It soon became obvious that the beam couldn't be adjusted and, indeed, that it didn't seem to uncage at all. The experimenters were concerned that Schmitt hadn't deployed the detector properly and, in the end, he was asked to make repeated visits, finally hitting the instrument with a tool in an effort to get it unstuck. It was all in vain; subsequent investigation revealed that a design error, essentially an error in the assumed strength of lunar gravity, meant that the balance beam wasn't heavy enough to uncage.
The first EVA had been a bit frustrating for Jack Schmitt. He wanted nothing more than to get out and do some geology; and, by the end of the first day, he was concerned that, if he and Cernan had to leave early for some reason, they would take home very little information about the geology of Taurus-Littrow. At the ALSEP site and, then, at their one geology stop, they had collected samples of coarse-grained basalt which, undoubtedly, represented the top layers of the bedrock that underlay the soil. However, they hadn't seen or collected any rocks that might be representative of the deeper bedrock or of the Massifs and, therefore, the site was not yet well characterized. Now, on the second day, they were going to be able to get to work and, indeed, the second and third EVA's proved to be exciting, productive, and full of fun.
This first stop proved a geologic bonanza and, consequently, Houston decided to lengthen the stay to the maximum allowed by the walkback constraints. With the Apollo 14 experience as a guide, NASA had made a conservative assumption that, in the event of a Rover breakdown, the astronauts would be able to maintain an average walking speed of 2.7 km/hour, about half the running speeds achieved by several of the astronauts over distances of a hundred meters or so. Making allowances for reserves - but no allowance for the backup capacity provided by the Oxygen Purge System (OPS) - the assumption of a 2.7 km/hr return speed meant that, at this farthest station, Cernan and Schmitt had to leave no later than about three and a half hours into the EVA. During our review of this summary, Jack Schmitt said, "I remember arguing with them about how conservative the walkback assumptions were. Particularly where your landmarks are clear of you have Rover tracks to follow. You could almost certainly get into a fairly efficient motion that would have been better than 2.7 (kph). I can't document any estimates that we ever made, but we always thought that it was pretty conservative. On the other hand, the reason I didn't argue about it very much was that there was going to be plenty of things to do. You didn't need to go very far (away from the LM) in order to reach all the interesting places that we wanted to get to in the time that we had available."
In all, Cernan and Schmitt spent sixty-four minutes at Station 2. It was one of the longest stops made during Apollo and, still, it was a frustratingly short time for so productive a stop. They sampled the two major rock types evident in the area and, although it is still an open question as to which of the rock types is more characteristic of the South Massif, there was no doubt that the Massif, like the mountains at Hadley, is made up of breccias. The samples the crew collected gave the geologists at home a great deal to think about.
In reality, even more time was lost because the crew hadn't trained for a such a contingency and there was some initial confusion about whether or not both of them had to get off the Rover. Hoping to save time, Houston wanted the measurement made with the gravimeter sitting in its stowage slot on the back of the Rover but Cernan thought, at first, that he could sit quietly while Schmitt got off, started the measurement, and then collected a sample or two. However, the experimenters were concerned that the pumps and fans in Cernan's PLSS would perturb the measurement and it took an extra minute or two for everybody to decide that he had to get off.
Once Cernan was off and the Rover's suspension system had quieted down, Schmitt got the gravimeter started. Cernan had grabbed a camera equipped with a 500mm lens from under his seat and, while Schmitt used the LRV sampler to get some soil and rocks, Cernan took pictures of Massifs. The sampler consisted of what was called the Universal Handling Tool (UHT) and, attached to it, a stack of cup-shaped bags in a holder. The crew had used the UHT's to deploy the ALSEP. The tool was about a meter long. It had a pistol-grip handle and, at the other end, a socket-type fitting for the removal of ALSEP attachment bolts. At the business end, there was also a pair of retractable pins - worked with a trigger in the UHT handle - so that the tool could be locked into a suitably-equipped socket, such as one in the sampler head. The sampler made an excellent solo-sampling tool because Schmitt could collect a sample in the exposed, top cup of the stack and then remove that cup, seal it, and put it away before grabbing the next sample. The sampler eliminated the problem of manipulating a scoop and a bag at the same time, and the only real problem in using it was making sure that there was a pocket or a Sample Collection Bag (SCB) handy so that you could get rid of the sealed sample and free your hands. Here, Schmitt had to hold on to the sealed bags until the gravimeter measurement was done and he could put them in an SCB that was hanging next to the Rover console.
Within a few minutes, the gravimeter measurement was finished and the astronauts were ready to mount the Rover. To do so, they stood at the side of the vehicle, next to their seats and facing forward. They gripped a handhold next to the console between the seats, jumped up and sideways, kicking their feet forward. With luck, they fell into a sitting position; but, here, Cernan missed his jump and fell to the ground. With the Rover handy, he had no trouble getting up and, in the process, noticed that he had uncovered a layer of very light-colored soil below about two inches of darker, brownish-grey surface soil. Most of the Apollo crews uncovered light layers from time to time and, in most instances, what they were probably seeing was highly-shattered - and, therefore, light-colored - ejecta from relatively recent impacts, with the top layer having been turned dark by the subsequent effects of countless small impacts which produce small globules of relatively dark glass. Here, however, the light material probably represented the unaltered landslide material and it only took Schmitt a moment to get a sample.
The next stop was planned for the rim of a small crater a few hundred meters north of Hole-in-the-Wall at the base of the Scarp. The astronauts had something of a wild ride coming down the slope and, once they were off, Cernan claimed a lunar speed record of "17 1/2 to 18 clicks (kilometers per hour)". While his claim can't be independently verified, there is no doubt that he was moving quickly and that he had managed to avoid a spinout in the process.
The three things that the Backroom really wanted at this site were a double core tube which Cernan would drive into the ground, a gravimeter reading, and a pan. The core tube promised to keep Cernan busy for most of the twenty minutes - especially because the geologists in the Backroom wanted him to put the lower half in a sealed can. Basically, this was a one-man operation and, in the meantime, Schmitt could take the pan and do some solo-sampling. However, Schmitt's forearms were very sore and, as a consequence, he wasn't able to work with his normal efficiency. The source of his forearm soreness that, during the drive out to Station 2, the camera bracket on the front of his suit had started to work loose and, all through the drive, he had been forced to grip the camera so that he didn't lose it. Once they got to Station 2, he and Cernan managed to tighten the bracket, but the effort of keeping his hand closed against the pressure of the suit meant that his hands and forearms sore and tired as he started to work at that stop. An hour later, the soreness and forearm fatigue had only become worse; and the drive to Ballet Crater hadn't been long enough to give Schmitt much relief.
Although the LRV sampler had it's advantages, Schmitt's tool of choice was a scoop with which he could be more selective in sampling and, as well, could be used to dig small trenches. However, solo-sampling with the scoop and the packet of flat bags attached to the camera bracket required some finesse and, with tired hands, Schmitt was short on finesse at Ballet Crater. The head of the scoop could be angled at 90 degrees to the handle but, once a rock had been captured, it was no easy matter to get a bag open and then get the head of the scoop high enough to dump the rock into the bag. Later in the mission, Schmitt worked out a technique of resting the scoop head on the ground and then walking his fingers down the shaft far enough that pouring was a relatively easy matter; but, here, solo-sampling proved to be much more of a chore than it had been for those astronauts who had longer arms and/or used tongs as their solo-sampling tool.
In order to close a sample bag, Schmitt had to get rid of the scoop for a moment but, with the head angled, it couldn't be stuck in the ground. Naturally, he rested it against his leg but, time after time, it fell to the ground. The job of grabbing it up was made a little easier by the raised rim of the crater because Schmitt could put his feet downslope. However, the slope also made balance a bit tricky and, not only did Schmitt drop his scoop, but also his packet of sample bags; and, in a final moment of frustration, he accidentally kicked over an SCB he had put down near him. At one point, he took a spectacular, spinning fall onto his hands and knees and, once he was up, had to take a couple of minutes to make sure that his camera hadn't been damaged. Fortunately, the camera and lens were okay and Cernan soon came over with a pair of tongs to help Schmitt collect the scattered gear. In a successful attempt to lighten the mood, Parker told Schmitt that "the switchboard (at Houston) has been lit up by calls from the Houston Ballet Foundation, requesting your services for next season," and in response, Schmitt did an impromptu audition, managing two big hops on his left leg, with his right leg flexed up and back about as far as was possible in the suit. Twenty years after the fact, Schmitt still feels the frustration of Ballet Crater; but, at the very least, the episode illustrates the problem of finding the right combination of tools and technique, particularly for unrehearsed activities. By the end of the mission, Schmitt had learned enough that solo sampling was no longer a particular problem.
As was typical of an Apollo 17 geology stop, once Cernan had the Rover parked, Schmitt hopped off and took a quick look around while Cernan took care of the dusting and the other house keeping. They were parked near a highly shattered boulder and Schmitt went over to take a look and then take a pan. Being a little gun-shy from his experience at Station 3, Schmitt wasn't about to start sampling until Cernan was ready to help him. Having looked at the boulder, he backed away to start the pan and immediately noticed that there was something very unusual about the soil that he'd stirred up with his feet.
"Oh, hey!", he said, obviously excited.
He paused for a fraction of a second. At the Scarp gravimeter stop he'd seen spots of color on the ground which, after a moment's consideration, proved to be spots of sunlight reflected off the gold foil on the front of the Rover.
"Where are the reflections? I've been fooled once."
And then he was sure. "There is orange soil!!"
The orange was all around him. He was very excited.
Cernan, who was still dusting, hadn't seen the orange soil yet and, at first, thought that perhaps Jack was letting his imagination run away from him. "Don't move it until I see it," he said.
"It's all over!! Orange"
"Don't move it until I see it," Cernan said again.
"I stirred it up with my feet," said Schmitt as he pondered the implications and started to think about a plan of attack.
By now, Cernan had turned around to look. "Hey, it is! I can see it from here."
"It's orange!", exclaimed Schmitt again.
Cernan wanted to be sure that he wasn't being fooled. "Wait a minute. Let me put my visor up." But there was no doubt. "It's still orange!"
"It sure is! Crazy!"
"I've got to dig a trench, Houston," Schmitt said.
"Copy that. I guess we'd better work fast," said Parker, conscious that they would soon be up against the walkback constraints again.
"Hey," said Cernan, "he's not going out of his wits. It really is."
If the Ballet Crater stop was a comedy of errors, the Shorty stop was a demonstration of the efficiency that could be achieved by a talented, well-trained, highly-motivated crew. The patch of orange seemed to form a band that ran parallel to the rim of the crater and as Schmitt dug a trench across the band, it became evident that, under a thin layer of altered surface soil, the ground was a deep red at the center of the band, fading to orange toward the edge. By the time Schmitt had finished the trench, Cernan had finished dusting the TV camera - so that Houston could have a good look - and arrived with the gnomon and a supply of sample bags. The gnomon was a lovely little device consisting of a free-swinging staff mounted on a tripod base. The idea was to put the gnomon down on the ground next to a sample so that, in the pictures, the gnomon shadow provided information about orientation while the gnomon itself provided a vertical reference and a length scale. In addition, there was a color-and-grey scale on one of the legs to provide calibration for photo processing. Schmitt and Cernan didn't have to spend much time talking about what they were going to do. With the trench already dug, they took documentary photos; and, then, with that done, Schmitt used his scoop to get the first of several samples while Cernan got a bag open and ready. As soon as a sample was in the bag, Schmitt turned to present his SCB to Cernan who, once he'd sealed the sample bag, put it in Schmitt's SCB. Schmitt then turned to get the next sample while Cernan got another bag ready.
While the crew was getting trench samples, people in the Backroom in Houston were debating what they wanted next. On Earth, orange or rust-colored rocks and soil around volcanic vents are often the result of literal rusting of iron by volcanic water vapor. If this was the cause of the orange soil at Shorty then, small amounts of volcanic gasses might still be present and, at first, what the Backroom thought it wanted was a trench sample put in a vacuum tight can. However, by the time the crew was satisfied that the trench had been properly sampled and Cernan was on his way to the Rover to get the "short can", there was a change of heart in Houston. What they wanted was a double core which could later be sealed in one of the vacuum tight rock boxes.
"Did you want that in the orange," asked Schmitt?
Back in Houston, Parker heard a chorus shout "Yes" on the Control Room comm circuit and told the crew, "We can put cores in grey soil all the time."
Schmitt remembers thinking, at the time, that they might learn a bit more about the vertical distribution of the material by moving off the side to a thinner part of the deposit but, in hindsight, is very glad that they drove the core into the center of the orange band. When he and Cernan pulled the tube out again, the soil in the bottom wasn't red or orange, it was black. Back at the Rover, while Schmitt was getting a quick sample of the boulder, Cernan took the two sections of core apart and found that the bottom of the upper section was a very dark grey as well. As it turned out, the dark color - and the orange as well - was, due to the presence of tiny spheres of volcanic glass, with the color differences having been produced by variations in rates at which the two types of glass cooled. Later, examination of soil samples and cores collected at other stops showed that both types of glass are widely distributed on the floor of Taurus Littrow and are the distinguishing component of the so-called dark mantle. Billions of years ago, when the valley was being filled with lava, fire fountains laid down deposits of pyroclastic glass which were then covered and protected by later lava flows. Subsequently, various impacts dug up glass along with fragments of basalt and, as the rock fragments were ground down into regolith, the glass was mixed in, giving the area its characteristically dark surface color. At Shorty, a layer of pyroclastic glass remained protected by overlying lava until the impact punched through about 19 million years ago. As mentioned previously, in a cratering event the ejecta is laid down as an overturned blanket; and the presence of the orange soil near the rim indicates either that it was dug up from nearly the deepest point of penetration or that it was injected into a rim fracture by the force of the impact.
Had there been time, Schmitt and Cernan easily could have spent several hours exploring the Shorty ejecta blanket and taking samples. Unfortunately, because of the extra time spent (very profitably) at Station 2 and (less profitably) at Station 3, they had only thirty-four minutes available at Shorty. They were still more than four kilometers from the LM and were right up against the walkback constraint. By the time they had the core back to the Rover, they only had thirteen minutes left. Working as quickly as they could, Schmitt finished preparing the core tubes for the trip home while Cernan ran over to the elevated southeast rim of the crater to take a color panorama. From his relatively lofty perch, Cernan had a good view of the rim beyond the Rover and it was only a moment or two before he spotted more of the orange soil. Beyond the boulder, he could see "a lot of orange stuff that goes down, radially, into the pit of the crater" and more patches of it around to the north side of the crater. Clearly, the impact had exposed a great deal of pyroclastic material but, not only was there no time to do more sampling, there wasn't even time for Cernan to give more than a quick verbal sketch of what he'd seen. After the mission there would be time to examine the pictures and to talk with the geologists and to figure out what it all meant. In the mean time, Parker wanted Cernan back at the Rover so that he and Schmitt could be on their way.
During the first EVA, Schmitt had found coarse-grained basalts at the ALSEP site and, again, at Station 1. The longer a piece of lava takes to cool, the larger the grains in the resulting piece of basalt and it was a bit of a puzzle that they had found no pieces of fine-grained basalt which presumably would represent the uppermost layers of the lava flows. Camelot is a large crater, six hundred meters in diameter, that seemed young enough that the ejecta blanket would include a good selection of boulders dug up from as much as 150 meters below the valley floor. On the way out to Station 2, Cernan and Schmitt had driven by Camelot and had seen an extensive field of waist-high boulders on the southwest rim.
On close examination, the Camelot boulders showed many of the same characteristics that Schmitt had seen in the rocks at the ALSEP site and at Station 1. The boulders were made up of coarse-grained basalt and, in places, contained sheets of hollow, spherical cavities - called vesicles - left by a froth of gas bubbles that had formed in the cooling lavas. Now there was no doubt that they had identified the dominant form of the Taurus-Littrow basalts. There was still the question of why they weren't seeing any fine-grained versions, but that was a question to be answered through a detailed examination of the regolith samples back on Earth.
For about 20 minutes, Cernan and Schmitt worked in the cramped quarters of a boulder field, conscious of the potential for snagging their feet. They collected samples of the rock, samples of soil thrown up on the rocks by nearby impacts, and comparison samples of soil scooped up from between the rocks. They worked quickly and efficiently and, now pleased with themselves for a day's work very well done, skipped and sang as they made their way back to the Rover and, then, to the LM.
On the whole, the Station 6 boulder appeared to be a large piece of breccia like those they had seen at the South Massif, but there were some puzzling features that were only clarified toward the end of the hour. In places, Schmitt found vesicles that indicated that at least part of the rock had once been molten; and, eventually, he found a contact surface - a boundary between a blue-grey breccia and a tan-grey, vesicular breccia. Flattening of the vesicles in the tan-grey rock and evidence of melting in the blue-grey near the contact showed that the tan-grey breccia was very hot when it intruded into the blue-grey. Here was evidence that the Serenitatis impactor had struck deep layers of breccia formed in prior impacts and that, as the mountains were raised, streams of molten rock were injected into fractures. Both the flattened vesicles and caught-up bits of the blue-grey breccia in the tan-grey were indicative of a thick, viscous flow. Had Schmitt and Cernan been rushed at Station 6, they might have missed some of these vital clues and the geologists back home might not have bee able to piece the story together from the samples. However, here the astronauts had enough time to make a fairly complete field study of the boulder and to make the critical observations.
After the mission, only Cernan had any regrets about their work at Station 6 and, at that, he was only sorry that he hadn't taken time to write his daughter's name on a dust-covered, uphill shelf on the boulder. He'd collected a sample of the dust and the spot can be seen in a famous picture he took of Schmitt next to the boulder with the valley visible beyond. Fortunately, Alan Bean was able to correct Cernan's error by painting the scene and adding Tracy's name. To those who know the story, the Station 6 boulder has become known as Tracy's Rock.
Before they could move on to the next stop, Cernan and Schmitt were faced with the tricky problem of getting back on the Rover. The vehicle was parked with Cernan's side uphill and it didn't look as though he would have any particular problem. But Schmitt had visions of not jumping high enough up into his seat, missing, and rolling downhill. As Scott and Irwin had done in a similar circumstance on Apollo 15, the 17 crew decided that the best plan was for Schmitt to walk down to a small crater where Cernan could get the Rover level enough for him to climb on board.
If the climb up to the Station 8 boulder had been strenuous - and it is important to note that, as a result of the climb, neither of them experienced peak hearts rates of more than 130 beats per minute - the trip back down to the Rover was nothing short of fun. At Station 6, after finishing his pan from above Tracy's Rock, Cernan had headed back toward the Rover using a high-speed skip. As he came up out of the boulder track, he got his weight too far over his right foot and took a spectacular fall. Because the soil was soft, because there were no exposed rocks, and because Cernan was moving downslope as he landed, the fall looked worse than it really was. In truth, he fell slowly enough that he had some control and landed on his hands and knees, even managing to avoid hitting his camera on the ground. Indeed, the fall was so benign that, twenty years after the fact, neither Schmitt nor Cernan could remember the incident. More immediately, at Station 8 the only adjustment that Cernan made as a result of the Station 6 fall was to change his downhill gait to a series of big, two-footed kangaroo hops. These gave him more stability but without any sacrifice of speed. It was fun and Schmitt gave hopping a try, too. As he made his way downhill, he started making skiing noises - Shhhh, Shhhh, Shhhh, Shhhh, Shhhh, Shhhh.
"Can't keep my edges," he said, trying to hop from side to side, pretending that he was skiing moguls. "Shhhoomp. Shhhoomp. Little hard to get good hip rotation."
Unlike the frustrations of Ballet Crater and the excitement of Shorty, the mood of Van Serg was one of puzzlement. As Cernan and Schmitt approached the crater, they drove across a landscape littered with football-sized rocks and, the closer they got, the more Cernan had to maneuver. The Rover had a clearance of about 14 inches and, at low speed, it was certainly possible to run a wheel up and over taller rocks. But, here, there were so many rocks that Cernan had to turn frequently and he estimated his "wander factor" to be as high as fifty percent. That is, to go forward ten meters, he had to drive fifteen. The large number of rocks indicated that Van Serg was an impact structure. However, although the crater lies well out in the middle of the valley and should, like the larger craters around it, have dug up basalt, the rocks looked different from anything they had yet seen.
While Cernan dusted - and he had a great deal of dusting to do because the replacement fender had finally failed - Schmitt made his way up to the crater rim. The rocks looked highly shocked, he said, probably thinking about the boulder at Shorty. However, the more he looked at them, the more they looked like breccias. Many of the rocks seemed to contain light-colored fragments within a darker matrix and there was nothing that looked like the coarse-grained basalt. And, when the astronauts started to sample, they found that the rock was fragile and easily broken.
"I'm not sure I understand what's happened here, yet," Schmitt said. Van Serg "should have brought up (basalt) according to the theory, and it hasn't."
They never did find anything that was clearly basalt. As Schmitt complained, everything was covered with dust. In addition, there was no sign of any orange soil or anything else that even hinted at volcanism. It was a puzzle, and neither the crew nor Houston seemed to know what to do about it. Cernan and Schmitt collected samples, and then there didn't seem to be much else to do besides take a pair of pans and climb on the Rover for the trip to Sherlock. As they sampled, Schmitt wondered if, perhaps, Van Serg had hit a "window" in the basalt layers and had penetrated into an underlying layer of breccia; but there wasn't any way to answer the question by doing a few more minutes of field work. Houston wanted Cernan to take a few 500-mm pictures of the North Massif while Schmitt finished sampling. Then it would be time to go.
By this time, Cernan and Schmitt had been out for nearly five hours. They had been working hard all day, scrambling around on the hillsides; and, at Van Serg, there had been nothing like the discovery of the orange soil to keep them going in the face of sore muscles. While Cernan took the 500s, Schmitt started a planned "radial" sample, a series of samples taken on a line extending out from the crater rim toward the Rover. The "radial" had been planned as a solo activity; and, therefore, Schmitt had the LRV sampler with him. It was attached to a device called a yo-yo which consisted of a small, spring-driven reel hooked to the suit, a two-meter-cable, and a clip to which the LRV sampler or one of the pairs of tongs could be attached. When not in use, the cable was wound on the reel and the tool was held tight against the suit. If Schmitt then wanted to use the sampler, he merely grabbed it and pulled to unwind the cable. When he was done, he let go of the sampler and let the spring rewind the cable and pull the tool out of the way. The trouble was that Schmitt also had his scoop with him and, as his troubles mounted, he wished that he'd had Cernan take the scoop back to the Rover. At first, the scoop was merely a nuisance because he could plant it in the ground, out of the way, while he used the sampler. However, all through the day, the latch which let him change the angle of the scoop head had been getting more and more difficult to use because of dust that was getting in the mechanism. And the latch wasn't the only thing that was getting fouled. There was dust in the locking collar with which the scoop was attached to the extension handle; and, as Schmitt grabbed the scoop to move to the next spot, the lock failed and the scoop head fell to the ground. Tired as he was, he managed to get down to retrieve it, using the extension handle as a crutch; but, as he tried to get up, he had trouble and had to run forward several steps to regain his balance. In hindsight, he believes that, had he not been so tired, he would have been a bit more cautious. He was working near the crater rim and was surrounded by rocks big enough to have caused a problem had he tripped.
Schmitt decided to go over to the Rover to get rid of the scoop; and his decision triggered one in Houston. The geologists decided that they weren't going to learn anything new by continuing the radial sample and Flight Director Gerry Griffin agreed. Parker told Schmitt to abort the radial and told Gene to finish up the 500s. Schmitt readily agreed that it was time to leave.
There was a bit of housekeeping to do - in particular, a gravimeter to be read - and, as they got back to the Rover, Gene suggested that they needed a sample of the soil. Because he had the scoop in hand - the head now re-attached - Schmitt started to take a quick sample and, almost immediately, found a layer of very white soil about 3 or 4 inches below the surface. Fascinated by his discovery, he started to dig a trench, all traces of fatigue gone from his voice. Although Houston had been insisting that they leave Station 9 immediately, Cernan and Schmitt made a crew decision to stay for another few minutes so that they could get a trench finished, get some pictures taken, and get some samples bagged. They worked rapidly and efficiently. Houston did not interrupt.
While Cernan and Schmitt were digging, Griffin and others in Houston had an earnest discussion about an extension at Van Serg. The geologists were now a bit more enthusiastic, but Griffin was concerned about fatigue and, in particular, about the astronauts' hands. However, because Cernan and Schmitt seemed to have been revitalized by their discovery, Griffin decided to grant the extension and Parker informed the crew that the Backroom wanted a double core and some football-sized rocks.
Schmitt was skeptical about the feasibility of doing a double core. The ground was littered with rocks and there was every reason to believe that Cernan would run into more as he tried to hammer the core tube into the ground. If Schmitt had regained his enthusiasm about Van Serg, his fatigue hadn't completely disappeared and his tiredness was made evident when he started to argue with Houston about doing the core.
Not surprisingly, Cernan decided not to get involved and got busy assembling the double core tube. In hindsight, Schmitt says that he should have realized that Cernan wouldn't have much trouble. The rocks they'd tried to sample had broken easily and, as Cernan hammered on the core tube, it would meet occasional, momentary resistance and then would break through. Schmitt's difficulty in thinking this through was probably another symptom of the fatigue that had been masked by the discovery of the white soil.
Because Houston had decided to drop Station 10 completely, the Station 9 close-out was actually a fairly relaxed affair. The astronauts got the core sections separated and capped, changed film magazines, removed the data recorder from the SEP receiver, and deployed a seismic charge. There was even a moment or two for Houston to do some exploring independently of the crew. For a moment, it looked as though they had made a momentous discovery.
What happened was that Ed Fendell, who was operating the TV camera remotely from Houston, was doing a TV pan at the end of the Van Serg stop when someone in Houston noticed a patch of orange on the East Massif. Fendell zoomed in to take a closer look. Zooming didn't help; and Parker finally had to ask the crew "What's out there in the distance on a hillside in the field of view? The camera is pointing at it." And then, before Cernan or Schmitt even had a chance to figure out what he was talking about, Parker had the answer. "Oh, I'll bet it's the Italian flag, I'll bet. On the charge." What he realized was that Schmitt had put the seismic charge out about 10 meters east of the Rover. At the tip of the antenna, there was a small, bright, orange pennant to serve as a warning flag and to make the charge more visible in color photos. When Fendell panned by the charge, he was looking at the mountains and the TV lens set at intermediate zoom. The pennant filled only a few picture elements and was badly out of focus, looking like a blurred patch of color on the hillside. Once Parker figured out what was going on, Fendell pulled back on the zoom and brought the pennant into focus. None of the people involved remembers why they called it the "Italian Flag", although Parker thinks it may have been a reference to the less than enthusiastic participation of Italian troops in World War II.
As we have discussed, none of the Apollo missions could be more than a quick scouting trip to a particular landing site. The Kennedy deadline forced NASA to build the simplest set of hardware capable of completing a landing mission and it is a credit to the design teams that, by the time of the J-missions, crews could spend three days on the Moon and had Rovers to extend their range. There was never any hope of doing more than scratching the lunar surface and producing an outline of lunar geologic history. By the end of Apollo 17, there were enough samples of the mare lavas and the highlands breccias that the geologists could be confident that they understood how the big basins like Serenitatis had been blasted out by impacts, how the mountains had been raised, and how the mare had been formed by flows of lava episodically welling up from the lunar interior. And there were intriguing details which, if not completely explained, seemed consistent with the general themes. If, for example, some geologists were disappointed that no evidence of recent volcanism had been found at any of the sites, the discovery of the orange and black soils at Shorty - combined with Schmitt's subsequent mapping from orbit of similar regions elsewhere around the borders of Serenitatis - made it easier for geologists to describe the mare filling phase of lunar evolution.
Our scientific understanding of the Moon will, of course, change and improve when we resume lunar operations sometime in the future. Gene Cernan liked to describe Apollo 17 as the "end of the beginning" and certainly, from a scientific perspective, Apollo was an outstanding start.
Beyond the science, and beyond the historic significance of the program, Apollo was also a chance to learn something about living and working on the Moon. As we move forward into a lunar base era and, in the long term, toward the creation of self-supporting lunar communities and industries, an examination of the Apollo experience will provide some practical lessons about getting work done under lunar conditions. Certainly, the crews demonstrated that, with some additional attention to suit design, future lunar workers will have no significant problems with mobility and dexterity. Not surprisingly, there were problems with equipment and procedures - many of them caused by the dusty environment - and, certainly, for longer term operations it will be essential to have the capability to clean, refurbish, and repair equipment on a regular basis.
By the end of the third Apollo 17 EVA, the lunar dust was causing a number of practical problems. As we have discussed, the locking collars on the extension handles and the pivot on the scoop head had become fouled with dust and were difficult to use. In addition, the replacement fender had failed and, as Cernan and Schmitt made their way back to the LM, they drove in a shower of their own dust. And then, once they stopped, Schmitt found that the gate latch on the back of the Rover - which, because of dust clogging had been giving them trouble since midway through EVA 2 - had failed, and the gate was flapping in the breeze. What is more, both extension handles and the attached scoop and rake had fallen off sometime since Van Serg. At the end of Apollo 16, Charlie Duke brought his scoop home and, although there are scratches on the scoop that were probably made as he used it to pick up rocks, a cursory examination of the latch mechanism did not indicate any substantial wear. It seems likely, then, that, had Cernan and Schmitt had the time and work space to take the tools and even the Rover indoors for cleaning and repair, they could have continued to get good use out of the equipment for far longer than three days.
However, three days and a cramped LM cabin was the most that any of the Apollo crews had available; and, under the circumstances, an amazing amount of good work was done. Because they were able to build on the experiences of prior crews, Cernan and Schmitt hold virtually all of the records for time spent on the surface, distances driven, numbers of samples collected, numbers of pictures taken, and so on. Building on the experiences of prior crews, they had confidence in their ability to get the work done. Like the prior crews, they quickly learned how to use the lunar environment to their advantage; and, although procedures and equipment will be developed that will make it possible to conduct lunar base operations even more effectively, there is much that can still be learned from the Apollo experience.
Jack began his comments by noting that he had argued for an extension to a 4-EVA mission by reducing the science payload. I asked him how much would have to have been removed. "As I recall, it wasn't a lot, because of the significant margins they already had in the mission planning. I think you also had to give up some of the margin. Early on, right in the beginning (of the Apollo 17 training and planning), I asked Gene if he had any problem with me discussing the possibility of a fourth EVA with some people. He didn't, so I did. But it was clear that Chris Kraft didn't have much interest in it. Deep down inside - and maybe not so deep - some people didn't want to fly 17, but they didn't know how they could get out of it. They said, 'Hey, we've gotten away with it this long, why don't we quit before we kill somebody.' Some people were talking that way right after Apollo 11."
Gene reacted to Jack's comments with the following: "Jack did a lot of lobbying, about two points. He wanted to land on the backside of the Moon, which I didn't think was going to happen. It's not a question of whether it could have been done; it was whether it was practical to do with the hardware we had. And the other thing was extending to four days and that's not something I really don't remember too much about. My gut feeling is that I was not too excited about spending an extra day without a good reason. In retrospect, had I known everything was going to go so well, I would have liked to have spent a week." Gene then switched to Kraft's reaction to Jack's proposal. "I dealt with Kraft off and on and I knew Kraft's feelings about our mission, all the way. He wanted us to get there and get home alive. I mean, as late as a couple of days or a week before the flight, he and I sat down and had a good talk about that. And his interest was for me not to take even the slightest additional chance, if I didn't have to. It was not mandatory that we land. It was mandatory that we get home alive. And Chris said that to me because, frankly, he knew I wasn't going to the Moon a second time without landing. I think he probably knew that Jack had worked up some ways for the AGS to help us if we lost part of our computer on the way down and need the AGS to finish our landing. But Kraft, all along, would have not wanted us to spend an extra day."
After our discussion of an extra EVA, I mentioned to Jack a question I had put to Pete Conrad - namely, why he and Al Bean hadn't gone more than 300 meters from the LM. I had expected him to make some comment about the suits or the PLSS's but, instead, he said that they wanted to be able to get back to the LM in a hurry in case something started to go wrong in the spacecraft and they needed to fix it or leave. I also told Jack that I had mentioned Pete's answer to Armstrong and that Neil said he felt the same way.
Jack responded by saying, "On Apollo 11, nobody ever suggested that they go very far away from the LM. I don't remember that ever being a consideration. As 12, you know, was really programmed to be the back up to 11 and I think it was just general inertia that kept them from moving very far away on the second flight. but with 11 and 12 under your belt, and particularly with the way the LM performed for 13, people just said, 'Hey, it's all right. Houston can watch it. You guys don't need to worry about it.' And I didn't. Gene may have, but I didn't. I think that one thing that I had that the other guys never got was an extra level of confidence in Mission Control. Because I worked with those guys, right from the very beginning. I figured it was a good way to learn the systems. they had some little simulators they used. they knew the schematics. I just went to bed with those guys. And no other astronaut ever did that, at least while I was there. So I knew their capabilities were; and not only as individuals but also, from a systems point of view, I knew what they could watch. In my own mind, during all the simulations, I was competing with them. AS friends, but I was competing with them to try to see what the simulations people had done to us before they did. They almost always won, because they had better information. but it was still a competition. Nobody else did that. Some people look at me funny when I say that I didn't worry about the systems going bad. I just flew the mission and figured that it something was going to go wrong, we'd take care of it at the time. And I think I had that attitude because of that extra level of confidence that I had in the people who were watching the spacecraft. Now, I'll bet you that if the Apollo 12 landing had been off by a factor of two or three, they still would have gone to the Surveyor. Even at a thousand meters, I'll bet they would have gone. the pressure to do that would have been very high. I don't remember about the mission rule about how far they could go, but it wouldn't have been the first mission rule we waved, depending on circumstance."
I noted that Pete had been fairly firm in his statement about not going very far from the LM.
"Yeah, but that's because he landed near it. I'll bet he would have been just as firm about getting over to the Surveyor if he'd been 500 meters away and knew where it was."
In addition to having some doubt that Conrad would have "gone over the hill to get to the Surveyor", Gene said, "Jack worked very closely with those guys on simulations. He drank beer with them. He knew them. He trusted them. He liked them. And he depended upon them. Now, I liked them. I drank beer with them. I trusted them. They were your best friends on the ground. But they weren't with me on the Moon, and they weren't flying that spacecraft. And this goes back to the fact that Jack doesn't have a long history of flight experience. Jack has never been on his own out where his ass was hanging in the sky. I think Jack flew because he had to fly, to become qualified to go to the Moon. And when that was done and he got out of the space program, he never touched the controls of an airplane again. Now, that's not a problem with me. Jack did a hell of a job and I want to go into that later. But for me, the bottom line was that Mission Control was not the final solution - we were. I don't care how many guys are on the ground. I don't care how many shifts they're working. I don't care how many simulations you've run with them, when you're out there, you're out there by yourself. Now Jack would say, 'Well, you're really not by yourself, you've got all those guys taking care of you.' They can watch you, but they can't do anything for you. And I think that's where the aviation philosophy comes in. When I'm out there on a dark night and a 500-foot overcast and I got to land on that god-damn carrier, those guys have got me on radar. They know who I am, they know where I am, they know how fast I am. And when I'm coming into that deck, they know whether I'm high or whether I'm low and whether my wheels are down, and whether my flaps are down. Everything there is to know about it. But none of them are flying the airplane. And none of them are going to hit the ramp. And none of them are going to fly into the water. I'm going to do that. And I liked the guys and I hit the beach with them. I drank beer with the Combat Information Control Officer and the LSO, the Landing Signal Officer. They were your best friends. Just like the guys in the MOCR. But the bottom line is that you're the one responsible, and you're the one accountable. And what your accountable for and responsible for is the success of the mission and your own ass. And I don't think Jack has that inbred philosophy and therefore - and this is not a bad rap, it's just the difference in our backgrounds - he used to depend on the guys in the MOCR. Anytime he was in a simulation or in the spacecraft, it was like they were sitting next to him. But they weren't. They were a quarter of a million miles away. And the interaction between me and them was just like flying in bad weather. I was flying with my son-in-law - and he flies - and he said "What if they told you to descend to an altitude and you had a problem with that or they told you to take a route and you didn't like it?" And I told him "If you remember nothing else when you're in an airplane, they're on the ground and you're up here. You're the commander, you are the decision maker in that airplane. Now, you can't violate rule; but if you don't want to accept something that they've told you to do, you just say, 'I'm sorry, I can't accept that' or, if you have an emergency and you need to say 'I can't descend to that altitude' or 'I can't take that heading'. You're the commander. They're just there to help you. And it's the same philosophy in a spacecraft. It doesn't change at all."
Sensing that Jack and Gene were, perhaps, talking about different aspects of the question, I said to Gene, "Let's go back a little bit to the LM. 11 and 12 versus later missions. Neil and Pete both said that they were conscious of the LM being there. They wanted to be able to get back in 10 minutes or 15 minutes if they needed to. But then, after 12 and the other flights, the community got enough confidence in the LM, that you, Gene Cernan, were willing to climb on the Rover and go to a place where you were an hour's drive away. So you have some greater confidence either in the spacecraft itself or in the ability of people to watch it from the ground."
Gene said, "I think that's a fair statement. We built on the accomplishments of the preceding missions. Now, it certainly is nice to know those guys are watching my helium pressure and my battery temps, or otherwise I'd have to carry a telemetry system on the Rover or on my back. So it was nice to know those guys were watching, and the fact that they could alert you to anything that might be wrong was very important. So I think the confidence grew in two areas. One, confidence grew in the LM itself; and not only in the fact that it worked but, also, that you could do things like shut down the inertial nav system. And we thought about that a lot before we decided you could do it. Because, once you shut it down, if you couldn't power it up again that was a big deal. But we got confidence that you could power it back up. It's like having a marginal battery in your car and you think you've driven it enough to charge it back up, but that first time you shut it down, you're just not sure it's going to start again. It's that kind of feeling and attitude. And we gained confidence, also, in the ground's ability. Working with Mission Control was so very positive. Could you have done the whole mission without those guys? Could we have gotten home without them? Yes, we could have, because we had to and we planned to be able to do that. Maybe not as precisely but we would have done it. (Going back to confidence in the LM) The LM's response to the thermal environment was always a big question. Well, we found out that there appeared to be no degradation on the shorter flights. And we found out that the ground could, indeed, from a quarter of a million miles, pretty accurately follow what the systems were doing while you were away. And, so, I think we built confidence, and that's why we were willing to go further away. But, you know, on Apollo 17, we were 6,7,8 kilometers away - and I don't care if we had the Rover to get back with or not. It all depended on how fast the problem would generate itself and how much confidence you had that you could get back in time. but, if something was going bad quickly, your chances of getting off the ground were not very good. You had to get back to the LM - walk or drive back - say you're 20 or 30 minutes away. You had to get in and, granted, you're going to bypass doing certain things if you've got a leaky helium pressure tank or you've got something else that's going bad pretty fast. Now, if you've got something that's degrading more slowly, something that might not be very good tomorrow, that's another story and you shorten the mission from three days to two days and you come home. But, there's always the possibility of something that could really give you a problem -something not very subtle and it's pretty obvious - and, when you make a decision that you're going to go over the hill to grandma's house, and you look over your shoulder and you can't see the LM because it's over a hill or is too small to see, you've just made a decision that goes beyond confidence or not confidence in the LM. You've made a philosophical decision that you're going to take the chance, that the risk is worth it. You leave the LM in the best shape you can leave it in, you leave it as fail-safe as you can, and you leave it in the hands of the people who can't fly it for you or fix a problem, but who can watch it for you and say, 'we don't like what we see, why don't you guys get home.' Now, if you had an Apollo 13 kind of thing, you can forget it, because you're not going to get it home. And I knew that. Yes, we did what we did on 15, 16, and 17 because we had more confidence in the LM, more confidence in the response to the thermal environment, more confidence that the ground can stay on top of it. But we also said 'Why are we here? Let's go out and look around.'
"You know, it's kind of sad that in addition to all the other problems we'd have in going back to the Moon - like it's going to take twice as long as it did the first time (15 to 20 years versus 8) - I don't know that we have the mentality today to build upon what we did on Apollo. And it's sort of sad. Because if we went back again next week or next year or in another decade - which we probably won't, unfortunately, because it's going to be another generation - I don't know if we would have the mentality ( I don't want to say "guts") to take the kind of risks we did when we did it the first time. Landing on the Moon was a risk. And I believe our inability to take risk today wouldn't allow us to do what we did when we did it. And that's a sad commentary; and I really feel strongly about that.
"Some people think that I'm crazy for having gone to the Moon twice. I mean, some of my peers think I was crazy. They think that going out there once was enough and wouldn't have gone a second time if they'd been given the chance. Some of them didn't even want to go once. Now, I'm not setting myself aside; I'm just saying that sometimes there are risks worth taking."
(Returning to the issue of confidence) "Jack says that he was always competing with the guys in the MOCR in simulations. Well, we all were. Simulations were war games for us. Figuratively, the simulations guys wanted to kill you. And that's where you built up your reputation as a pilot. And, if I ever had any supporters to get a crew or to get 17, it was probably because of some of my performances in those simulations. Not because I went to bed with the guys in the MOCR, but because they knew that I knew my business. They knew their business and I knew my business. When we had simulations, we were all working together, We were competing against the simulation guys, but the MOCR and the crews were always working together. Jack says "I didn't worry about the systems going bad." Well, the ground could not do anything about the systems. And that's what I mean by Jack looks at the MOCR as being his co-pilot. The MOCR was not my co-pilot; it was ground control. They were there to help me. but I think that's the pilot mentality. On a dark, foggy night coming aboard a carrier, there isn't anybody in the world who's going to help you except you. I had a lot of confidence in the people who were watching. But they were limited; they were a quarter of a million miles away when it came to doing something about a problem. Not that the MOCR - and I was part of the MOCR - didn't bring the guys on Apollo 13 back. We devised flight plans and the dynamics and all kinds of things for them. But the guys who had to execute, the guys whose lives were on the line, were up in that spacecraft.
Now, Jack had a different attitude about all this, and that's just because of a difference in background. And it's not a knock at Jack. I mean, Jack can look at a mountain and see a lot of things that I can't because of his background and experience. He'll know whether to look at the left side of the mountain or the right side and I might walk right up the middle, without knowing what the hell I'm doing. I think that when Jack (and the other "scientist-astronauts) were selected for the program, Deke Slayton said 'If you're going to fly on my spacecraft, you're going to fly in my airplanes, too'. And there were some guys who looked at it as an opportunity and there were other guys who learned to fly airplanes because Deke said they had to do it. I think Jack looked at it as a square he had to fill to get to the Moon. Jack's objective was to get to the Moon, and I admire that, and he did well. He was a great Lunar Module Pilot, and Apollo 17 would have been done any better if I had flown with the best stick and rudder guy around. Jack flew airplanes because he had to fly, not because he wanted to fly - as evidenced by the fact that he hasn't flown since we came back. And, therefore, as part of his scenario, he looked for all the help he could get. And the MOCR certainly was help. Essential help. But they just weren't at the controls."