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EVA

Sol 13: Valles Marineris, Mount Sagewood, and the elusive caves

Today our crew was interviewed by Amnon Govrin, a space enthusiast blogger. He brought his twin 9-year-old sons, and we had a good time showing all three of them around our Hab, GreenHab, Musk Observatory, and Engineering Station. Amnon came equipped with a sharp camera and a list of questions for us. The kids seemed really taken by anything vertical: the steps we climb up to our living quarters, the ladder to the storage loft, the hills outside the Hab, and so on. We had planned for an EVA to leave just as Amnon arrived, so he and his sons could see the whole suit-up and EVA preparation process.

I led EVA 19 off on a quest for Valles Marineris, accompanied by Mike and Darrel. In some ways, the Mars-y names assigned to these local Utah features feel a little weird. Our local Olympus Mons doesn’t rise much more than 65 meters above the surrounding plain, rather than the jaw-dropping 27,000 meters attained by the Olympus Mons on Mars (three times taller than Mount Everest). Likewise, our local Valles Marineris surely could not compare to the 7,000-meter deep feature on Mars. But I’d heard that it was still a sight to see, so I wanted to investigate first-hand.

Darrel and Mike as we hunted for Cactus Road

Darrel and Mike as we hunted for Cactus Road

This was a bit of challenge, since Valles Marineris is positioned on the same Cactus Road that we failed to find on EVA 16. The road had been washed out so badly that, with patchy snowcover littering the terrain, I couldn’t be confident that we were *on* a road. I am (maybe overly) cautious about exploring into the unknown because I really hate to cause any damage to the desert terrain, even aside from the BLM requirement that we stay on trails. But today we went out with fresh determination and scouted away from Lowell Highway until we found bona fide ATV tracks, just around a hill. Encouraged, we took off down “Cactus Road”, which was actually the muddy bottom of a trickling runoff creek.

Mike and Kiri enter Valles Marineris

Mike and Kiri enter Valles Marineris

We came upon Valles Marineris almost immediately, as our creek-bed road cut down through 30-50 feet of layered rock. The mini-canyon walls rose up, revealing beautifully bedded layers. I was torn between stopping to photograph and inch along each bit of exposed section, and wanting to explore further with my EVA-mates. We’d only been out for about 15 minutes, and I knew we all wanted to go further than that! So we drove along further, eventually striking a road leading up a snowy slope to the south.

We crested the hill and found ourselves on a wide plain. Truly deep canyons dropped off in the distance to our left (later we confirmed them as Candor Chasma, the subject of EVA 8). Closer in reach, a mountain with beautiful, striking bands of purple and red towered to our right. Squinting, I could even detect a tiny green layer sandwiched in. “That’s where we might find fossils,” I said, pointing. “That’s probably a green shale layer, deposited in a marine environment.” Darrel immediately jumped on this and proposed hiking up to the distant layer. I was a little leery of the steep, muddy slope, but it was just too tempting to pass up!

Mike ascends Mt. Sagewood

Mike ascends Mt. Sagewood

We scrambled and pawed our way up the flanks of the mountain (later identified as Mount Sagewood). At the top, we picked our way along the green layer’s exposure, conveniently at about hip-height. It topped a series of vivid red and purple bands, and the colors glowed in the noontime sun. We didn’t find any fossils… but may have found traces of endoliths, and the variety and beauty of the sedimentary structures was more than enough satisfaction for me.
Kiri digs at the green layer

Kiri digs at the green layer

We then climbed the last 30 feet to the top of the mountain and enjoyed a beautiful panoramic view, with the Hab in the distance to the west, Olympus Mons and Factory Butte jutting up to the northwest, Valles Marineris dropping away to the north, and Candor Chasma floating like a heady mirage of sedimentary nirvana to the east. We oohed and ahhed and took tons of pictures, then carefully descended back down to the ATVs. Our trip back was quick, but very muddy. I waved Mike on to take the lead from Cactus Road home, and he clearly enjoyed racing through the muddy streambed, bouncing off rocks, and racing full-throttle back down Lowell Highway to the Hab.

You can view the full EVA 19 information, including a map.

Amnon Govrin and his sons were just getting ready to leave, so Mike and Darrel ferried them back to Hanksville, and I helped Brian, Luis, and Carla get ready for EVA 20. Their intended destination was the pair of caves that had eluded Luis and Mike on EVA 15. They were equipped this time with a series of GPS waypoints that should have led them straight to Canton Cave. Unfortunately, they got all the way up near the cave, in Serenity Valley, only to find that the road plunged into a deep channel that could not be safely crossed with the ATVs. While they could have walked the last kilometer on foot, they were running out of time. They returned home, even muddier than we had been, disappointed not to have found the cave but still glad to have had one last EVA.

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And here’s the full EVA 20 information, including a map.

It’s hit home with all of us that this has been the last day of our Mars mission simulation. Tomorrow will be filled with more cleaning, packing, and getting ready for the Hab handover to Crew 90. I realized that just recently our mode of operations here has really started to feel normal, and that I feel quite at home. Two weeks is just enough time to settle into a good routine, having smoothed out the rough edges. (It hasn’t hurt that Darrel has fixed or upgraded much of the Hab’s functionality during our tenure!) I expect it to be quite jarring to return to “Earth” life. I’ve certainly felt this to be a hugely educational, eye-opening, wonderful, beautiful experience. If what we’ve accomplished and learned can in any way translate into useful knowledge for a real human mission to Mars, I fervently hope that there will be a way for us to share.

Sol 12: Nightrider part 2

(continued…)

ATV covers make great light shades for laptop users

ATV covers make great light shades for laptop users

Brian showed me how the software worked so that I could help him prepare it for shot data collection. We had to update the current position each time Luis moved, and update the position of the land streamer each time we advanced it. It was good to have two people who could operate the software, because Brian’s helmet fogged up so that he couldn’t see the laptop screen. So we both hunched over the laptop, under the ATV cover we’d brought up with us to use like a photographer’s black drape. We poked at the laptop keys with two pens, since the suit gloves aren’t dextrous enough to hit the keys accurately.

Luis with mud-spattered helmet

Luis with mud-spattered helmet

Brian, Luis, and Darrel had previously worked out a system of hand gestures to communicate while collecting data, because we had to turn our suit radios off (they could cause interference with the data collection). So I’d enter the coordinates, Brian would wave vertically to Luis, Luis would swing the hammer, the laptop would beep happily when it detected the shot, and we’d repeat. When three good shots were collected, Brian would wave his hand horizontally and Luis would advance to the next location. I’d disarm the geophones while Luis moved, then re-arm them once he was in position again.

Brian replacing faulty geophone #3

Brian replacing faulty geophone #3

One thing we had not anticipated was how quickly running the laptop from the ATV’s battery (via an inverter) would drain the battery. After a couple of hours of data collection, the next time we tried to tow the land streamer, the rover almost wouldn’t start. Duh! Of course you need to run the rover for a little while each time and let it charge the battery. We didn’t have trouble after figuring this out.

Brian and the land streamer

Brian and the land streamer

Soon we’d settled into a great routine and were collecting shot data with high efficiency. Near the end of the sixth line, though, I noticed that the sun was touching the far horizon, and we decided that we’d have to stop at the end of that line. We finished the shots and started packing up as quickly as we could. At that point we realized that we were somehow short on bungee cords—and two snapped while we were strapping them on. So things weren’t as secure as we would like. Also, Luis was the only one with a headlamp, which was a bad oversight on our part.

It was nearly dark by the time we started for home. But our rovers have great headlights (if they didn’t have lights, we obviously wouldn’t have stayed out so long). In fact, visibility wasn’t a problem at all, and it felt perfectly safe heading home. The problem instead was with the strapped-on equipment. I had the laptops in a hard case strapped on the front of Spirit, but they were resting on that wretched heavy metal plate we used for shots. The plate was both smooth and had snow on it, which was a recipe for a very low coefficient of friction. Plus, the bungee cords weren’t really strong enough to hold the laptop and the plate in position. So every little bump in the road was causing the case to slide around. I started holding the case with my left hand and driving with my right (where the throttle is) but this definitely is not ideal on an ATV. Finally, after crossing an unusually bumpy mini-gully, I felt the case slide more than usual and decided to stop. I guess Luis was close behind me, because his rover bumped into mine (but not hard).

We climbed off and fiddled with the bungee cords. Brian, who had been in the lead with a faulty radio, finally realized that we weren’t with him and turned around and came back. We strapped the laptop case on the back of Spirit (on top of the sledgehammer) and set off again. This was much more secure, and the driving went more smoothly—until the plate started moving on its own and I realized that its bungee cord had popped one end off. I stopped (no impact this time), reseated the cord, and headed off again. This happened a second time. The third time, I was heading into a ditch and the plate slid off the front of the ATV. I let it go, since unlike the laptop case it wasn’t worth diving for to save. I stopped, climbed off, picked it back up, and Luis and Brian strapped it more securely. We then cautiously motored home, our speed limited far more by our burdens than the night conditions. Luis and Brian also had challenges—the bulky geophone boxes strapped on the back of the ATVs prevented them from fully sitting down, because our suit packs stick out so far behind us.

You can view the full EVA 18 information, including a map.

We arrived back to the Hab at 6:45 p.m., and never was that airlock so welcome! Darrel and Mike were waiting inside and helped us out of our suits. We removed packs, helmets, radios, gloves, hats, gaiters, boots, cameras, GPS units, etc. and climbed wearily up to our living quarters. Thank goodness, Carla had a hot meal waiting for us on our return!

Sol 12: Nightrider part 1

Hab Sweet Hab (in the sun)

Hab Sweet Hab (in the sun)

I spent half of today up on Radio Ridge assisting with Brian’s seismic survey. He’d gone out yesterday with Luis and Darrel to start the survey, but they’d had their EVA truncated when the Panasonic Toughbook they were using fell off the ATV and yanked the Ethernet port entirely out of the PCMCIA card, rendering it inoperable. Worse, when they returned to the Hab, we discovered that none of the data they had collected had been saved to the hard drive! Brian handled this disappointment stoically, however, and planned a second attack for today. In yet another feat of gosh-wow on-the-fly problem solving, Darrel was able to solder the connections back together (!) and fix the PCMCIA card (I had been certain it was toast!). But then, to make things even easier, he donated his own laptop for use on the survey today. We took both laptops, just in case.

Brian knew from his EVA yesterday that this process would take some time, so he was itching to get going early. We all were. I’d volunteered to join the EVA out of curiosity (I’ve never studied any geophysics or seen seismic work in action) but also because Brian clearly needed some helpers. Luis and Darrel were worn out from yesterday, but Luis agreed to come along as well today—and ended up doing the lion’s share of the physical work in the expedition. But I’m getting ahead of myself. Although we were hoping for an early start, somehow it just took a long time to get everything together, strap all the equipment onto the ATVs, and get suited up. We didn’t enter the airlock until 12:30 p.m., and then Brian realized that in our rush he’d missed his helmet bungee cord… so we waited to re-pressurize, he got his helmet fixed, and then after a 5-minute wait we were finally stepping out into the noon sunshine. It struck us immediately, right in the face (our helmets don’t have visors).

Setting off on EVA 18

Setting off on EVA 18

We saddled up, me taking Opportunity for the first time (I’ve always ridden Spirit previously). Opportunity is supposed to be the easiest to drive, because it’s the only one with a thumb-button gearshift (the others have foot-pedal clutches). But having gotten used to Spirit, it took me a while to get the hang of thumb-shifting. We took off across the desert, and my second lesson of the day struck. My previous ATV EVAs almost exclusively stayed on Lowell Highway. This time we were on a side trail—narrow, twisty, bumpy, and an entirely different riding experience! There were a few times that I thought to myself, “This is a ROAD?!” but there they were, twin tracks in front of me, leading the way. So I came up to a half-crouch and rocked with Opportunity, absorbing the jolts and bumps, standing up on the up-hill sections to lean forward and aid in the climb. It was more lively than the road drives—and I must say, a lot of fun! It’s funny how the ATV feels much more than a machine beneath you—more powerful, more animal, more alive.

Brian and Luis atop Radio Ridge

Brian and Luis atop Radio Ridge

We came up onto Radio Ridge, and I gasped with delight and awe—the valleys and hills fell away from us to the right, in colored bands and dappled with sparkling, shining snow. I hadn’t seen the sun out in its full glory in days. It was shining and sparking off every rock and bush. Mid-ridge Planitia spread out before us to the west, all the way to Skyline Ridge in the distance (now THAT looks like fascinating geology). We headed south to the seismic survey site, and I was bouncing and revving along in utter delight. There was a drop-off to our left that plunged back down to where the Hab is situated, and we stopped several times along the way to snap pictures of the awesome panoramic view. Since I had the camera, Brian urged me to say the word if I wanted another picture stop. “Only if you think we have time,” I said, since our main goal was to collect the seismic data, and we were late off the mark. “We probably won’t want to do it on the way back,” he said, and boy, would he be proven right.

We reached the site and Brian hooked up the laptop to the land streamer (12 geophones strung on a 55-foot cable). That’s when it really hit home to me how much work yesterday’s crew had done. Although they hadn’t gotten any data, they’d done all the surveying and marked out a 300-foot line in 30-foot increments, enabling us to just walk to the appropriate point without having to check GPS coordinates or mark anything ourselves. (The distances are in feet, by the way, because the geophones are spaced at 5-foot intervals.) We could get straight to work.

Still, it took us a while to fall into a rhythm. The way this survey works is that you lay out the land streamer, pressing each of the geophones into the ground, and then position a heavy metal plate at key points; you then swing a heavy sledgehammer and smack the plate repeatedly (each such blow is a “shot”). The laptop records the response from each geophone for each shot, and after collecting data from six shot locations, you then connect the land streamer to an ATV and drag it 55 feet further along the line you wish to survey. We did this six times. Luis turned in a heroic effort with the sledgehammer, doing almost all of the more than 120 shots himself.

We also saw mountain lion tracks!

(Stay tuned for part two… WordPress won’t let me put it all in one post!)

Sol 11: Seismic Shenanigans

After abdicating some tantalizing EVAs for the past three days on account of my not feeling well, I was looking forward to getting outside today and finally starting my seismic research project. I had originally planned to do the first seismic EVA yesterday, but I just wasn’t ready, so Kiri led the geology section EVA yesterday instead.

Darrel, Luis, and Brian in the airlock

Darrel, Luis, and Brian in the airlock

My morning was occupied with preparations for the seismic experiment. This included finalizing the survey coordinates and entering waypoints into the GPS, printing and laminating a survey plan, and fashioning several survey flags out of wire clothes hangers and flagging tape. I also strapped the big, heavy pelican cases containing the seismic equipment to the back rack of the Viking I and Spirit rovers. I affixed the sledgehammer, strikeplate, and two bright red buckets to the third rover Opportunity. At 11:30 am, I briefed Luís and Darrel on the EVA plan. It clicked with Darrel right away, but Luís looked a little confused. We ate a quick lunch of leftovers from previous meals and were in the airlock at 1:07 pm.

Our difficulties began almost immediately upon our egress from the Hab. Luís and I hopped on the Viking I and Spirit rovers only to discover that our EVA suit backpacks stuck out too far for us to comfortably ride the vehicle with the boxes behind us. Luís decided he could manage since the box on his rover was positioned farther back than the one on my rover. We had to move the box from the back rack to the front rack on my rover, and this ate valuable time.

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roving along

Twenty minutes later we finally rumbled off north from the Hab on the now familiar trail leading towards Olympus Mons. I led the caravan. With each dip and bump in the terrain, the box we had strapped to the front of my rover bounced. I had to keep a hand on it. Finally, just as we were turning west at the base of the hill crewmembers had climbed just two days ago, the bungee cords holding the box to my rover’s front rack gave way, and I barely caught it before it fell to the ground. I had to stop and put it back on the rover. Luís and Darrel helped. We moved it to the back rack where it originally was but were able to inch it back a little to give me enough room to sit down with the EVA suit.

On our ascent to the top of the ridge, we snapped a few photos and video footage. I had been here on EVA 13 just four days ago, and in that time the snow cover had thinned considerably. The dirt was even showing through in a few places. Another couple days of above freezing temperature, and the snow will be gone, replaced by the slippery muddy clay we experienced on our first two days at MDRS.

Darrel, Luís, and I enjoyed the expansive scenery of Mid Ridge Planitia as we motored south on along Radio Ridge under mostly sunny skies. I stopped at some of the same places where I’d taken geotagged photos on EVA 13 so Kiri could have overlapping shots for her auto-geolocation study. We arrived at the target location around 2:15 pm, a little over an hour after embarking on the EVA.

panorama overlooking Radio Ridge

panorama overlooking Radio Ridge

I should back up and explain why I wanted to do the study in this location. Nominally, the main goal of the experiment is to test the feasibility of collecting a 2D seismic profile using a towed land streamer (more on what those terms mean later). However, if the exercise can be carried out somewhere with interesting geology, that’s icing on the cake. As luck would have it, MDRS Crew 83 led by Carol Stoker of NASA Ames collected ground penetrating radar (GPR) data earlier this field season data and discovered a buried feature where the Kissing Camel Range (aka: “Dragon’s Head”) intersects Radio Ridge. The interpretation is that Kissing Camel Range is an inverted channel that is covered by the Cretaceous sediments comprising Radio Ridge. An inverted channel is former streambed that filled with resistive material. Over time, erosion removed the surrounding surface leaving the former stream behind as positive relief (hence the “invereted” moniker). Inverted channels have been spotted in multiple locations on Mars, and one at Miyamoto Crater has been identified as a potential landing site for the Mars Science Laboratory.

Darrel and Luis discuss the survey strategy

Darrel and Luis discuss the survey strategy

Our first task was to survey the line for the experiment. Ideally, we’d have a theodolite or total station to make this work easier, but being resourceful Mars pioneers, we had to make do with the materials at hand. In this case, that meant a 50 meter tape measure, some homemade survey flags, a handheld GPS unit, and a compass. First, I walked the nominal 165 meter (540 ft) line I had planned for the profile and marked each end with a bright red bucket. Then, Darrel and Luís stretched out the measuring tape while I started unloading and hooking up the equipment. We had to adjust the the line a few times before I was satisfied it was straight. Luís put the survey flags at all of the planned shot points and spread endpoints, and Darrel marked GPS waypoints.

land streamer and astronaut shadows

land streamer and astronaut shadows

Now we were ready to start the seismic survey. We pulled the land streamer out of its box and hooked it to the back of the Viking I rover. I drove the rover forward to extend the streamer. A land streamer is just a big cable with geophones attached to it that makes for relatively quick movement of geophone arrays. A geophone is the simplest form of seismometer. It converts ground movement into voltage that is collected in a seismograph, which is a rugged field computer for collecting seismic data. In our case, we have a string of twelve geophones spaced five feet apart. Since I’d spent the better part of three days playing with the geophones and seismograph back at MDRS, hooking it all up in the field wasn’t a problem. However, there was one big issue.

Brian with the dreaded laptop

Brian with the dreaded laptop

The Geometrics Geode seismograph we have requires a computer to control it. If anyone has ever tried using a laptop outdoors, you know it’s difficult to see the screen in the sun. Now try that wearing a spacesuit helmet and using an old Panasonic Toughbook that is at least 10 years old (meaning its screen is quite primitive by today’s standards). All of these factors conspire to make seeing the one means of controlling the system nearly impossible. It took a while, but I was finally able to boot the computer and load the necessary software.

Luis swings the hammer.

Luis swings the hammer.

We were finally ready to take our first shot. For those uninitiated in seismic exploration lingo, a “shot” refers to the source of seismic energy. It’s often an explosive source for large scale surveys, but for us a simple sledgehammer striking a metal plate will do. Darrel, Luís, and I took a few turns practicing our hammer swings before starting the data collection. Since radio interference could potentially corrupt the data collection, we turned off our radios and worked out a few hand signals to communicate. I squinted at the nearly black Toughbook screen while Luís took the first swing. The computer beep told me it successfully took a record of data, and Luís swung twice more so we could stack the data to improve the signal-to-noise ratio. Then, he picked up the plate and dropped it at the next flag. We repeated this for all six shot locations for the first spread location.

Then it was time to move the geophones 60 feet down the line and take more data. I drove the rover along while Darrel made sure the land streamer didn’t get tangled. I was impressed with how well the system performed and can appreciate why land streamers are very popular these days for enabling quicker more affordable seismic surveys. I had asked Darrel to tell via radio when I needed to stop, but I didn’t hear him. I overshot the mark and dragged the geophones too far. So, Luís and Darrel pulled on the land streamer while I backed up. This would have been fine except that I had drive over a big rock.

Going downhill over the rock meant the rover was tipped backwards pretty steeply. I had only loosely closed the box on the back of the ATV holding the equipment. When the rover pitched, the laptop slid out. In the process, it yanked the ethernet cable jack out of the PCMCIA card. Thankfully, the laptop itself escaped being run over by the vehicle, but the PCMCIA card didn’t fare so well. I shoved the ethernet jack back in hoping it would work, but it did not. The laptop started beeping, and it all three of us squinting at the black screen to get the computer rebooted.

to the Hab

to the Hab

It was clear that we couldn’t collect any more data with the computer until we fixed it, so we packed up and drove back. Luís led the way and took some amazing video footage along the way. When we returned, we were tired and hungry from the 4 hour, 19 minute EVA (our crew’s longest yet). Thankfully, today was a cooking day, and Carla and Kiri did not disappoint. They made baked tofu “cashew-dine” and vegetable couscous with apricot cinnamon biscuits and coconut brownies.

After a couple of hours wearing a headlamp and soldering tiny wires, Darrel was able to fix the Toughbook’s PCMCIA card. Kiri and I tried recovering the data from the laptop and to our horror found that it wasn’t there. According to the log files, the six shots we took today should have been recorded, but the data has vanished. Perhaps it’s related to the hard reboot we had to do in the field. Life on Mars is never easy. We’ll go back out tomorrow and start over. This time we’ll try putting the laptop in a cardboard box to reduce glare.

You can view the full EVA 17 information, including a map.

I’d like to thank Exploration Instruments, LLC for their generous loan of the seismic equipment for this study. Some day, astronauts on another world will need to conduct geophysical exploration of the shallow subsurface, and the work we’re doing helps identify how to modify terrestrial methods for extraterrestrial application.

Sol 10: Stratigraphy and Clue

Today during our morning planning meeting, we discussed what our remaining goals for the mission would be. Our first week was a constant barrage of learning new procedures (for science investigations adapted to this environment; for keeping ourselves fed, watered, and clean; and for keeping the Hab functioning). Now that we’ve found our legs in those regards, our attention has opened out to thinking more broadly about what we want to accomplish. And now there are just four days left of our mission!

Brian has spent hours learning how his land streamer of seismic geophones works, so that he can deploy it to collect a seismic refraction profile of an intriguing inverted channel. Darrel has struggled to find time to work on his radio-controlled plane, which has a camera and could potentially be used for scouting good locations for on-foot investigations. Luis wants to culture and analyze the biological samples he’s already collected. Carla wants to compile the results of her Mars Dessert Research Station efforts. 😉 I’ve been itching to get out and do some real geology, not just the tourist-geology I’ve accomplished so far (point and gasp and take pictures!). Of us all, Mike may be in the best position, having raised the radio telescope from 10 feet to 20 feet high early in the mission; he’s been happily collecting data ever since.

After much discussion about what our remaining EVAs might focus on, Brian determined that his land streamer deployment likely would require a seriously long (like all day) EVA—or even two such EVAs. He also needed some more time to plan just where and how he would deploy it. So we decided that I would use today to do a two-ish-hour EVA with a geology goal, and Brian will aim to do a seismic EVA tomorrow.

I jumped on the chance immediately. I wanted to find an outcrop and practice measuring a stratigraphic column in Mars-like field conditions (e.g., suit, gloves, helmet, etc.). From our crew’s previous EVA 8 to Candor Chasma, it seemed a likely place to find nice exposed layers. That crew had walked out to the Chasma, but we instead planned to drive up Lowell Highway to Cactus Road, aiming for the “Candor Chasma Access Parking” area, to shorten the trip.

Kiri and Mike contemplate the road ahead

Kiri and Mike contemplate the road ahead

So after lunch, Carla, Mike and I suited up. We exited the airlock at 1:45 p.m. and roared out on our three ATVs onto the “highway”, a moist concoction of snow and mud, but still quite drivable. As commander for the EVA, I led the group, with a mirror strapped to my left forearm so I could glance back and check on Carla and Mike without turning around (which is very difficult in the suits, and would be very unsafe if done while driving). I checked my GPS unit every so often so that I would know when the intersection with Cactus Road was at hand. I’d pre-loaded the GPS not only with our final destination but also with some waypoints compiled into a “route” (my first exercise of this GPS capability). Everything went fine at first—but then we overshot Cactus Road. We turned around and headed back slowly. I could see the waypoint blinking at me on the GPS screen, but we just could not find a road or track of any sort heading east of Lowell, due to thin but obscuring snow cover. After some dithering and scouting expeditions on foot, we gave up on that goal. Instead, I decided that we would head north on Lowell until we found an interesting outcrop and just map that.

Carla and Kiri traversing the Lowell North Sedimentary Outcrop

Carla and Kiri traversing the Lowell North Sedimentary Outcrop

As we went north, I was anxious—as commander of the EVA, it was my responsibility to make good use of our time, and I was thrown off by the failure to find Cactus Road. Would we even see anything interesting to the north? I’d been up there before on EVA 5 and only had a dim impression of lots and lots of soft, squishy, muddy Morrison Formation. I wanted solid rock with interesting structure to map.

Kiri delights in the outcrop

Kiri delights in the outcrop

EVA16_pano3 And then we lucked out! We spotted a low hill topped with some Dakota sandstone to the east of the road. (More accessible than the top of Olympus Mons, too!) We parked the ATVs and headed over on foot. And yes! It was fantastic! (Back at the Hab, we would learn that this site has a name: Lowell North Sedimentary Outcrop. So someone else thought it was worth study, too.)
Mike doing his Star Wars sandpeople impersonation

Mike doing his Star Wars sandpeople impersonation

We clambered up to the Dakota layer, and I walked Carla and Mike through the process of identifying layers and noting them down on paper. It definitely was good to have multiple people there. I couldn’t see my own suit well enough even to get the pencil out of my shoulder strap holder. We didn’t have a Jacob staff or Brunton compass, so we made do with a T-square we’d found in the EVA room, which had been augmented with a plumb bob to aid in standing it straight up.
Carla and Kiri sense a disturbance in the force

Carla and Kiri sense a disturbance in the force

We measured 13 distinct layers over 146.5 inches (the entire exposed section) and Carla and Mike took copious pictures to augment my hasty sketches. (Pencil, by the way, is highly superior to ballpoint pen in 36 F weather.) The layers were a combination of fine horizontally bedded sandstone, medium sand layers inclined about 30 degrees, and conglomerate layers with gravel and pebbles. Some of the latter seemed to have some inverse grading (finer grains at the bottom, coarser grains near the top), which can be created by debris (mud) flows, as opposed to deposition from water or air.

Kiri and the rock hammer

Kiri and the rock hammer

We spent a good chunk of time at the outcrop, then toured around it, also noting an impressive cave that sat below our level, under a treacherous overhang composed of the same crumbly/poorly consolidated rocks. We kept our distance from the edge despite its undeniable allure. I found a chunk of gypsum buried in some sand, and we collect a couple of other small samples to bring back to the Hab.

You can view the full EVA 16 information, including a map.

Olympus Mons from the northeast

Olympus Mons from the northeast

We returned at 4:07 p.m. Now I’m sitting at the work bench, writing reports, and savoring having done some field geology, here at MDRS! I plan to make up a proper section (to scale, with composition, grading, and layering noted) soon… when I can find time. Whee!

We’re planning to play MDRS Clue tonight. Darrel turns out to have some truly impressive artistic skills, and he became enamored of the idea of an MDRS-themed Clue game. So he put together a full game board, with MDRS locations instead of the traditional Clue ones; a set of character cards, based on the six of us and our roles; and a set of weapon cards (hydrochloric acid, horribly polluted GreenHab water, oxygen tank, wrench, rock hammer, and a cool lookin’ rock). The end result is really cool! We’ll leave it here for future crews to enjoy. (See the board below. He drew all the locations from photos of the actual areas and they are very realistic!)

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And with that, goodnight!