Based on the revised EVA plan sent from Houston, Scott and Irwin would travel due south toward the South Cluster of craters. They would temporarily skip the Station 4 stop there, as well as the Station 5 stop near Front Crater at the Apennine Front, and go directly to Station 6 at the Front. Despite the undulating lunar surface, which was pockmarked with craters and blocks, Scott managed a brisk 9 kph. The two astronauts kept up a running description during the traverse toward Station 6.
''A crater on our right now about 50 m in diameter with a lot of gray fragments on its rim,'' Irwin commented to Houston, ''and we're just passing one [rock] that's sitting right on the surface - about two feet, sub-angular. I can look out now and see the South Cluster and I get the impression of perhaps some horizontal beds in the first mound in the South Cluster. I do see a lot of blocks over in that direction; particularly the second mound - the west side of the second mound that appears to be in the Secondary Cluster.''
Scott and Irwin headed directly for Dune Crater, then skirted the rim of the crater by traveling counter clockwise. Despite its size, Dune Crater proved surprisingly subdued, according to Scott.
''We're on about the southwest side, now, of Dune Crater,'' Irwin continued. ''As Dave mentioned, we're heading 155 now. A very fresh crater at our 1 o'clock position with a lot of angular blocks; very slight raised rim about two feet above the general surface, but a very fresh crater. It seems like the albedo was lighter around that one than others that we've seen. In fact, you might be able to see that on your map, Joe. The lighter albedo in the southwest side of Dune.''
The geologists were also following along with their maps, but waited in anticipation for the Station 6 stop, where everyone could watch the TV images. Irwin and Scott continued south toward Spur Crater, but after more than twenty-six minutes of driving the rover, Scott told Allen he needed to stop and rest. The rover had really been taking a pounding from the wheels hitting the blocks, Scott was constantly working the hand controller to avoid the largest ones, and his concentration on the driving itself was fatiguing. Scott instructed Irwin to remove his camera from its mount and take a series of photos while panning. While Irwin did this, Scott took the opportunity to nibble on his food stick and drink some water. Refreshed, Scott resumed the traverse toward Station 6, which he reached sixteen minutes later. He had been driving for nearly three-quarters of an hour. Surprisingly, Scott reported that the battery temperatures were 75 and 81 degrees, and the drive motor temperatures were off-scale low, meaning they were running cool.
Scott had driven up the Apennine Front and parked the rover about 100 meters above the mare plain. Irwin got off and took a series of photographic pans that were among some of the most striking of the entire mission. The astronauts could see their Lunar Module Falcon roughly 5 km distant on the Hadley plain. Scott aligned the TV High-Gain Antenna, and shortly thereafter, Mission Control was treated to the spectacular vistas from Hadley Delta. In between photographs, the astronauts began their sample collection above the rover's parked location. Scott displayed his excellent sample recognition and descriptive abilities to Houston as he and Irwin picked up rock samples.
"The first one here is a fine-grain breccia - a micro-breccia - and it's got, it looks like, a third order with white clast in it. The matrix is dark black and it has glass within a fracture on the side, not unlike some of the 14s,'' Scott observed, referring to samples returned from Apollo 14. Scott continued his detailed description with the second sample.
"This is definitely a different kind of breccia, Joe," Scott added. "It's only got light gray millimeter-size clast in it with fine-grain gray matrix, and the clasts are about ten per cent of the total frag, so it's somewhat different.''
Scott and Irwin spent about an hour collecting samples, and Scott was even able to collect a core sample from the rim of a small crater below the rover with relative ease. This EVA resulted in significant soil accumulation on the LRV, elevating the temperatures on the communications equipment.
"Before we leave this area, we want you to brush the LCRU and the TV camera lens,'' Allen instructed the astronauts. "We're running quite hot on the LCRU and think there must be a lot of dirt on it.''
"Running the TV camera was really intense,'' Fendell admitted. "When the astronauts stopped and you took control of the camera, you didn't fool around and you didn't take your eyes away for an instant. We had a TV monitor up on the console, as well as the big screens at the front. If you turned away, it was all over. It was pretty intense staying focused on the job.''
Scott and Irwin continued filling sample bags with soil and taking more pictures before walking back to the rover to stow their samples and equipment. Ed Fendell had already positioned the TV camera in the stowed position looking at the battery covers. At Allen's comment, he panned the camera to the right toward the LCRU which revealed a layer of dust completely covering the mirrored LCRU radiator. Irwin took the brush and first cleaned the TV lens which made a dramatic improvement. He then brushed the radiator on top of the TV camera and then he slowly brushed the dust from the LCRU radiator, revealing its mirrored surface with each brush stroke, visible in the TV images beamed back to Earth. Irwin then tilted up the TV camera and made a second pass with the smaller TV lens brush.
"Would you check the oil too, please?" Allen joked. Irwin chuckled. At this moment of the mission, Allen's comment, while said in humor, truly reflected the overall mood at Mission Control in Houston as to how well Apollo 15 was actually progressing. It revealed a level of confidence in the equipment and satisfaction in the crew that was in fact the result of stringent engineering, testing, years of training and rigorous management. Apollo 15 was already an astounding success, and more discoveries awaited. Scott completed his 500 mm photographs and Irwin changed out a jammed film magazine in the 16 mm Data Acquisition Camera. Irwin then climbed into his seat and then the Commander climbed on, buckled himself in and drove west toward a boulder on the side of Hadley Delta. This stop was identified as Station 6A.
As the astronauts got off the rover again, they were impressed with the severity of the slope, and had to lean into the hill to maintain their balance. Trying to align the High-Gain Antenna with Earth, Scott knew, would prove very difficult, so he told Allen that he would bypass the television for this station stop.
''Okay, Dave. Whatever you say,'' Allen acknowledged, understanding. The geologists in the science support room were not happy with that announcement, but they would have to be content with the audio feed and examining photographs when the crew returned. Allen asked Scott if this was because he could not get into the right position to align the antenna with Earth.
''Yeah, that's right, Joe,'' Scott answered. ''The slope is real steep and, like I mentioned before, the sighting device doesn't transmit enough light to really make it very easy to find the Earth. I think it would take me a couple of minutes just to find you, and I think you've seen the same thing. But if you would like, I'll give it a try.''
Allen advised him to proceed with the sampling without having to align the antenna. Scott had parked the rover above a boulder a safe distance, but after making a practice descent halfway down toward the boulder, he decided he would move the rover closer. Scott had to cautiously side-step his way back up to the rover. He got on, buckled himself in then flicked the switch on the hand controller to reverse. He pulled back gently on the hand controller and backed up slowly. Scott could not see behind him, and Irwin, standing nearby, guided him with brief verbal cues. Scott wanted to move far enough to be able to turn the rover, travel down slope, then park it just below the boulder. The loose lunar soil was deep, and Scott very slowly drove the rover down to its new position. He parked it cross-slope and got off and Irwin moved over to the rover to keep it from sliding. The rover's left rear wheel was actually up in the air. Irwin actually asked Scott if he was afraid they might lose the rover on this steep slope. With absolutely no television images being beamed to Earth and only audio being heard, the scene in Mission Control and the Backroom must have been tense at this point. Allen implored Scott to make an attempt to align the High-Gain Antenna as best he could so Houston could try to capture some live TV of their situation, but the brief stop, coupled with the steep slope conditions did not make aligning the antenna a priority for this stop, and Houston agreed.
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