Aug. 1, 1971: Roving the mountain front

Apollo 15 makes its longest traverse

****

            What is it about our flight and water?  We had the water leak in the Command Module during our transit to the moon.  And now we wake to this:  A spill of about 25 gal. in the back of the cabin, coming from a damaged filter.  We’ve got plenty of water remaining, but cleaning the spill — scooping it up with used food bags, takes time.  Replace the damaged filter.

            And then another water worry:  bubbles in the water coolant lines of the backpacks could block the flow.  We have to take the time to drain and refill it. We’re delayed getting outside by damn near 1.5 hr.

            Finally we’re ready, depressurize the cabin at 7:47 a.m. EDT.  After 55 min. loading up the Rover, we depart, heading south for Station 6 on the slope of Hadley Delta.  “OK, we’re off.  We’re moving.”

            It’s a beautiful day for a ride on the moon, shadows shortening, Hadley Mountain emerging from them, the sun 14 degrees high in the black sky than yesterday.

            And amazingly, the front steering has healed itself overnight — it’s working.  “It’s quite responsive.”  Hard to get used to.  It’s damn near too much.  Press on, press on.  

            We roll through and around craters, note the debris pattern around them.  “There’s a fresh one — with angular blocks on the rim.” 

            Once again, we find it difficult to identify craters.  “We’re definitely east of our track yesterday.”

            “We’re coming up on a sharp one.”   Whoa — press on.

            “See if I can find a reasonable path through here.”  We dip and swish left and right, bound ahead like a puppy.  Hey — can see the South Complex of craters on the plain before the mountain front.  We’d originally planned to stop there, but press — no time, a shame.  A shame so much we can stop, sample and experience.

            “The surface is covered is covered with more debris here than what we’ve seen before.” 

            “Look at some of those big ones — they’re like 3 meters across.”  Rough, angular blocks.  We pass by the south side of Dune Crater which is part of the South Complex of secondary craters splashed up by impacts.   

            As we approach the foot of the mountain, the rocky debris lessens once we reach the mountain front. “Boy, that’s a big mountain when you’re down here looking up.  My, oh, my — that’s the biggest mountain I’ve ever looked up.

            We descend into a little depression that runs along the foot of the mountain.  “Like we’re driving in a valley.”  And the valley takes us to the mountain front. “We are starting upslope.”  A gentle slope at first of 3 – 4 degrees.  We stop a moment to see where to proceed.  

            “Let’s go to the rise ahead of us.”  We moving along the front now, angling uphill, easterly (the opposite direction from the rille).  We’d planned to go further, to a crater we call Front.  No use wasting the time — there’s no blocks in that direction.  We climb a slope of 8 – 10 degrees, riding about a quarter mile up from the mare floor.  

            We don’t see any fresh, deep craters that may have excavated bedrock, just shallow ones.  A disappointment.  Joe tells us to take a few samples of rock fragments representative of the area.

            We’ll call this Station 6.  The drive here took 43 min.  Pick at a few rock fragments.  Damn disappointing.  “There isn’t much debris around here.”  We’d hoped to find bedrock containing rock called Anorthosite, a piece of the original lunar crust.  Nothing here, a waste of time.  Press on. After 5 min., we drive a couple minutes to a more promising location up the slope, drive for a big ol’ boulder, the largest we’ve seen, 10 ft. across.  We’ll tag this stop as “Station 6a.”

            Wow, this is steep. You just don’t realize how steep the slopes are.  I don’t know if we can do this.  We try parking the Rover on the slope above it — too steep.

            We back up and swing below the boulder — dismount.  Whoa! As we get off the Rover, can feel it slip.  

            “I see a lot of green in that boulder.”  We gotta get a taste of that.

            And, on that slope, in that soft ground, the Rover begins to slide away.  

            Grab it!  And you do — grab it on the downslope side, grab the frame and keep it from galloping off.  Hold on, one wheel off the ground. 

            Houston is alarmed. “We’d better abandon this one,” Joe calls.  “The block is not that important.”

            Nervous, isn’t he?  Naw — by God, I’m gonna get a sample of that.  You keep tight rein on that Rover.  Chip, chip with the hammer and there’s our sample.  It’ll prove worth the effort.  You know, long after our flight, geologists determine that the green was part of the original ocean of olivine magma covering the moon.

            After 21 min. skiing the dust here, let’s get off this steep slope.  We drive 4 min. westward and downslope in the direction of the rille to Station 7.   We’re at Spur Crater, about 300 ft. up the slope and 3 mi. from Falcon, a small silvery insect on the rolling mare floor.  Just look at it.

            And this time we find a level spot at the northwest rim to park.  We’ve only less than an hour at this stop.

            “You come up here and look at this.  It’s got green in it, light green.”   By golly, more green on the moon, this time green soil.    It’ll turn out, it’s green due to volcanic glass beads tossed by “fire fountains.”   Thrown out by volcanic vents eons ago.  Imagine that.

            Ah, no time to indulge the imagination.   Look at what we have here.  We both spot it, sitting on a pedestal of bland gray rock as if placed on display. 

            “Guess what we just found.”  A white rock, the size of your fist.  As if placed for us to find, it sits on a a pedestal of gray rock — like a display in a jewelry store.  White — look at those crystals — could mean, should me — damn it, gotta be:   Anothorsite — from the original lunar crust.  “I think we found what we came for.”

            Hey Joe.  “Oh, boy, I think we may have ourselves something close to an Anorthosite.”  On Earth, it’s 11:18 a.m. EDT.  

            What a beauty.  We grab it, then sample all around it, including the rock pedestal on which it was perched.

            The white rock becomes Sample 15415, dubbed by the press as “The Genesis Rock.”  It will be dated at 4.1 billon years old — not the oldest rock we’ll bring back, it turns out, yet formed before the Imbrium basin was created.

            Wow — what a site, ol’ Station 7.  We tell Joe, this is a gold mine.  We’re working hard an fast, slip-sliding, skiing around on this slope.  We work as a team — one picking up samples with long-handled tongs while the other holds open a sample bag.  Photographing the location where we pluck it.  Everything bagged and documented.  We really work the rim of Spur Crater, side-slipping around on 20-degree slopes.  As many samples as we can.  A gold mine.

            We poke and prod every which way imaginable — that means digging a trench  and taking a core sample.  We own this place.  Alas, for only a limited time.

            We run against those walk-back limits.  But — this big one we gotta pick up!  There’s always one more rock we wish we could pick up or sample.  

            “All we really need is soil,” Joe says.

            Come on, just a soil sample, Joe?   Ol’ Joe can read our minds and adds, “And maybe some grapefruit-to-football-sized rocks.”   Quick to it, as Joe warns, “We’ll want to move in about 3 min.” 

            After 50 min. at the site, we’re moving, down the front, closer to home, gaining against those limits. Our oxygen consumption has been less than anticipated, so the EVA is extended and on the way from the slope, we’re able to make a stop we bypassed — Station 4 at Dune Crater, part of the South Cluster of craters, secondary craters formed by ejecta from impacts to the north.  Could Dune have tossed out some of the precious bedrock?   Look at that — that outcropping around the crater wall.  And boulder on the rim, right where within reach. No sooner do we stop than Joe says we’ve only got about 10 min. here.  We do all the sampling we can, with just time to dash to a boulder on the rim and chip off a sample.  “Let’s head back to the Rover.”  And after 17 min., leave on a drive of just 22 min. to the LM.    

            We’ve spent 4 hr. traveling and working the slopes of the front.  Alas, we have to come back to the ALSEP site and that damn drill, first stopping at Falconfor 10 min.

            OK, let’s see if we can finish this heat-probe hole.  We grind away at it for 15 min.

            Are your hands hurting? Now we attempt the third hole, for the deep core sample.  Hey — it goes in smoothly.  At first. Damn — we hit a hard layer.  Keep grunting at it.  We’re going to get this thing — up and down, lifting to clear the chuck, then down, biting a bit deeper.  

            “It’s tightening up again, Joe.”   We waste 15 min. on this effort.  We only have a hole about as deep as the first.  How about it Joe?   He says, “We’re satisfied with this hole.  Go ahead and emplace the heat-flow probe.”

            Even the damn probe sticks, won’t go down all the way.

            “We’ll take what we’ve got,” Joe says.

            That should be it for this damn drill.  Certainly they won’t ask for the deep core.   But they do.  They do. They want us to attempt to drill another 10-ft., this time with the core tubes.  So we begin to drill.  The core tube goes in easier, as it smoothly contains the soil rather than jamming it aside for a hole.  Feel those vibrations as the drill cuts through dense layers.  Damn hard work — damn hard on the hands.  We reach about 8 ft.  That’s plenty enough

            “Just leave the drill on the stem,” Joe says.

            Leave it?  Leave it for tomorrow?  No! — if we have to eat time on our last moonwalk for this thing, we’ll have to cut back the traverse.  We’ll probably lose the stop at the North Complex.  

            “I’ll just try it now.”  Gonna get this core out, finish this thing.  Pull!  The stem comes up maybe a foot.  “I’ll get it!”  But it won’t budge anymore.  Damn — we’re never gonna get it out.  Should leave it.  And I mean permanently.

            We return to the LM and perform another task delayed from the first walk:  We erect the U.S. Flag, pounding the staff in with a hammer. “I’ll hit it a few times so it’ll stay up here a few million years.”  Time for our tourist photos with the flag.  Give it a big Air Force salute, Falconin the background.

            We close the hatch at 3 p.m. EDT.  The moonwalk has lasted 7 hr. 15 min., and we’ve traveled 8 mi.  Three previous flights only covered 4 mi. — total. It’s been the greatest day of exploration ever, not even counting the work Al Worden is doing on orbit mapping large-scale lunar features.  He even spots what look like volcanic cinder cones in the Littrow region that will lead to that area’s selection as the landing site for the final Apollo. 

            Unlike Al, we can literally smell our work inside the repressurized cabin.  The dust we’ve carried in on our suits, despite a careful dusting before coming up the ladder, gives off an acred smell, sorta like gunpowder. It’s with us as we sleep our final “night” on the moon. 

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