100 Sols on Cape York — An Absurdly Brief (Read: Long) Summary (Part 6/8)

Part 6: Drawing Blood — Homestake

Sols

2763 to 2772

"tl;dr" Description

We found Martian drywall.

Highlights from Matt's Notebook

Sol 2763:

> We found two veins, one that is easier to reach and one that is harder to reach. The latter is a "richer" target. 

> Science says that these veins could be one of the more important targets at Cape York, if not the mission. 

> I don't get the excitement over the veins. Then again, I'm not a geologist.

Sol 2771:

> Homestake ate our winter haven mapping margin. MSL launch looming. Caffeine supplies dwindling.

Sol 2772:

> These are good times.

Sol 2773:

> The vein is Gypsum. Science is ecstatic. I want to blog about this, but I can't yet. Feels like a secret club.

Sol 2775*:

> Saturday planning! John bought pizza!

Details ("the deets")

When we first stumbled on the vein (which we named Homestake), there was this strange disconnect between the reality that I had been seeing and the reality that the science team was pushing. We had bought all this extra time hauling booty across Cape York's spine in order to go to the northerly slopes — which were now on the order of tens of meters away — to start mapping them with local imagery, and yet at the same time there was this very strong push-back from the science team. There was this vein, you see, but I'm not a geologist and I didn't know what it meant. Even before we knew what it was, the science team had some idea in their collective head what it could be and it would mean — whatever it was.

In all honesty, it was this disconnect from reality that had me asking myself, "Why would we stick around?" I didn't see what they saw.

But, alas — more push from them to stick around. We, the engineers, yielded what amounted to all of our planning margin time to stick around. We needed APXS and MI, more APXS off to the side, some Pancam 13-filter images; we needed everything up our sleeves in a matter of a few days, and we needed to fit it within a strategic plan. (Which, by the way, is hard. Most of our time spent in meetings that we organize to discuss strategic issues are spent trying to figure out what the question is in the first place; the rest is cake after that. You have to wade through the abstract and the absurd and the speculative for a good hour an a half before someone and speaks up and says, "Oh, so the 1-sentence summary is that we want to know… [thing]." And then everyone is on board.)

We let the science team have their fun: We gave them their APXS and their MIs and their Pancams. From this, a fantastic view of the vein:

And they came back with these fantastic results: Gypsum (drywall, sort of). Meant something awesome, apparently. Our media relations guy came into the room — "Scott, don't tweet about this yet; Matt, don't blog about this yet. There'll be a press release, but not for a while." In the end, we could tell ourselves that everything was fine, that the detour was worth it, that the margin was all for worst-case scenarios anyways.

The only reason this works on MER is because of the size of its tactical timeline (days). For landers, orbiters, and everything in between, it's usually only engineering and flight system health and safety that operate on a responsive timeline. Why? Because decisions that must be made today are usually to save the spacecraft from harm, which means that the science payload takes a backseat — even though the flight system was built to fly the payload in the first place. First order of business is having a flight system that can support the payload system. However, with MER, scientific results can be processed very quickly and fed directly into the tactical timeline. We are "closed-loop" for both the flight system and the payload, something that is purely the result of pressing the reset button every day and saying, "Ok, so, now what?"

Which is pretty neat.

Another benefit of this tactical operations concept is that the engineers are directly hooked into the science. We attend their meetings and they attend ours. I don't understand their 7-dimensional plots and their phase diagrams and their crater impact analyses, but I do understand their meta-analyses (like, "This means watery bits were here," or, "This means that this was a really giant rock, like really really really big"). It's cool when someone you've never met dials in to the SOWG meetings in the morning and lays out their 1-paragraph justification for the observation they just requested. They're usually to the point and on the money — with some wiggle room when we translate from "scientist talk" to "engineer talk."

With the western detour to Homestake on the apron of Cape York now done, we could start mapping the purported north-facing sites on the north end of Cape York: our Havens.

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*I included a sol outside of the arbitrary timeframe of the Homestake investigation because Homestake caused this one. When we ate our margin away, we instituted a Saturday planning day to make up for a lost sol or two.

100 Sols on Cape York — An Absurdly Brief (Read: Long) Summary (Part 5/8)

Part 5: The Trek North — Shoemaker Ridge

Sols
2735 to 2763

"tl;dr" Description
Power started to look tight. It was time to go find those north-facing slopes.

Highlights from Matt's Notebook

Sols 2756-275:

> Science wants a "quick" detour to the western apron of Cape York. This will cost us 2 or 3 drive sols, at the most.

Sols 2760-2762:

> LTP reports that we haven't found much in the way of science on this detour to the northwest. Tosol we will hit the apron dead-on and turn NE.

Details ("the deets")

Here, traverses became important and meaningful again. We'd been hanging out at Tisdale and Chester Lake so long we were, for all intents and purposes*, as the same spot. As such, this part of the story is all about traverse maps and miles under our feet. The hunt for tilty goodness led us in the direction of Shoemaker Ridge, a newly-named formation that forms the backbone of Cape York.

We were in such a hurry that we actually had to forego some systematic and detailed observations of the Ridout boulder perched on the eastern edge of the small Odyssey Crater.

I'll summarize from my own words:

The primary reason for the trek north was, of course, to find those slopes that give us good sun angles for good power. All estimates point to Opportunity surviving the winter with plenty of margin. However, margin can easily be eaten away by the unknown unknowns. With that in mind, we tried to reason how quickly we'd need to find a parking spot. January seemed a good last-minute date to aim for, if push came to shove. With that date in mind, we considered one other major factor: The launch of the Mars Science Laboratory on November 25.

The view periods of the MSL spacecraft after launch mean that they happen to just interfere with all other Mars missions. Immediate post-launch priority for DSN coverage of a spacecraft is very high; Opportunity, being much older and of a much lower status for requesting DSN time, gets the short end of the stick along with everyone else. This means that we may very well lose the time we've already scheduled with the DSN. Some more strategic analysis showed that if we did not finish mapping Cape York's northerly slopes by the time MSL launched, December and January would not provide us enough time to do that mapping because the incoming solar power would be too low.

We had made it clear: Thanksgiving or bust.

There is some confusion about why we went to the north for power. The reason is because that's where the north-facing facing slopes of Cape York happened to be, and it had nothing to do with them being closer to the equator where there is more incident solar energy on our arrays. In fact, as far as some of our analysis tools are concerned, we're in the same place that we landed in 2004**. Even over some 30+ kilometers, there is no discernible difference in solar power than we can measure, all else (like tilt) being equal — and we can certainly expect the same for the few hundred meters that Cape York spans north to south. We also looked to the south towards Cape Tribulation, where there were even better north-facing slopes; they were too far away for us to make it in time for winter.

It's worth keeping in mind that our long-term strategy is go south towards Cape Tribulation because the strongest signals of sciencey things (smectites) were seen from orbit near its peak. The MER team — both science and engineering — kept this concept at the front of the conversations concerning where to park for the winter. After some long and fruitful discussions, it was obvious that Cape York hadn't given up all of its fruits yet. It was an entirely new type of formation with clues of some real juicy stuff at the Tisdales and Chester Lake. Putting on our 20-20 hindsight glasses, we now know that to go south for the winter would have meant a big missing piece of the puzzle that tells us about water on Mars. Without those glasses, we had to make a decision. We went north to the small "lily pads" that the orbital imagery and elevation maps identified as having 15 degrees or more of northerly tilt. Some of these lily pads were at least the width of the rover and there appeared to be some other targets worth our time, such as a nice set of outcrop or a perch spot for a high-resolution Endeavour Crater panorama. 

Backing out for context: Our arrival point at Cape York, by now some 60 sols ago; the suspected smectite goodies from orbital observations; and the suspected location of the north-facing lily pads for winter hunkering.

We greased the wheels up (literally, actually — we heat those suckers to get the lubrication flowing) and boogied on out of Chester Lake, climbing a very slight hill and crossing over the region of negative northerly slopes to the region of positive northerly slopes. The next half dozen or so drives along the Shoemaker spine were relatively uneventful, with the exception of a jut to the west and back to capture a small indent:

This area in the green is, in a way, a dead zone of Cape York. Not a lot of interesting things going here. At about this time, the science team started looking closely at those orbital images and making hypotheses: maybe there was an exposed "vein" in the rough? maybe we could snap a few images as we see them? maybe we could even poke at them? The RPs had made such good time cutting along Shoemaker Ridge (that green area) that we had bought ourselves a week (in sols) of margin for mapping the north-facing slopes with local imaging by the rover. 

Whaddya know, we found a good vein as we approached the western apron on Cape York (here, I maintain the same labeling for context):

As seen by Oppy on the approach:

Mmm. More in Part 6, a part I never really did in detail the first time around.

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*Not, apparently, "for all intensive purposes," as I found out probably two years ago. It unnerves me that I didn't know this for the first 23 years of my life. I can't tell if this is on the same level as an Ecam PUL not knowing who Robert Plant is, or a Mission Manager telling me they thought "God bless you" was actually something like "kuh-bless-ya" until they were 12.

** Blasted typos. "I assume that is because we landed through some weird subspace wormhole and went back in time right?" Mike the Mission Manager is ever watchful.

100 Sols on Cape York — An Absurdly Brief (Read: Long) Summary (Part 4/8)

Part 4: "… and then we have a RAT hole" — Chester Lake Gets It

*********************

Hey! I'm back! Spent a few weeks back in Colorado for the holidays and am now back in the groove. Time to continue where I left off: Chester Lake. At the time of writing, we're almost 100 sols beyond this part of the story — and 150 since we hit Cape York. 

Must… finish… this… story… 

*********************

Sols

2709 to 2735

"tl;dr" Description

We pounced on a flat outcrop and hung out — for a while. We even Mossbauer'd!

Highlights from Matt's Notebook

Sols 2719-2721: 

> Today's Secret Woids: Fran / animosity / Bobbie. I fear for their relationship because of the animosity between them. (*rimshot*)

Sols 2722-2723

> Squyres: "We've been preserving the RAT for this. It would be foolish to leave."

Sol 2730:

> How many RPs does it take to change a light bulb?

> My wonderful SOWG chair: "Yeah, turn it up to 11." I like her. 

Details ("the deets")

I didn't have a lot of tactical shifts between leaving Tisdale-2 and our next target. For about a week, I had this notion that the rover was faced one direction and the Chester Lake was at some spot on Cape York, only to find out that I was about 90 degrees and 20 meters, respectively, off. I blamed my busted ankle, which, in retrospect, seems a pretty fair judgement (as far as unfair judgements go).

After giving Tisdale-2 a taste, we started hunting down something smooth and representative of Cape York. We were here to get a taste of Cape York so that we could learn a little about Endeavour. We found just such a target: Chester Lake.

In particular, we focused on a nice smooth spot that we called Salisbury-1 (Salisbury-2 wasn't as appetizing, apparently), circled in pink here.

Now, context: a perspective shot on Cape York, vertically exaggerated by 5 times, looking northwest-ish (thank my Google-image-search-"RayArvidson"-until-my-fingers-bleed talents).

I have layered in my own annotations here, most notably the direction that the front of the rover faced for the Chester Lake campaign, to give an idea of where how Oppy was oriented. To the northwest: a feature called Shoemaker Ridge, which forms the spine of Cape York running roughly north-south. To the northeast, the inboard side of Cape York and the effective edge of Endeavour Crater. Lots of interesting things all around us.

And just to convince everyone that we were there, the MRO spacecraft used it HiRise camera to find Oppy perched right where we thought we were — we call it the "ultimate locator"!

Hey!

While we started thinking about taking a poke at Salisbury, we queued up a high-resolution Pancam mosaic of Endeavour — hey, whaddya know, our first Endeavour Pan!

Note the pretty. (Click for full-res.)

Suddenly, we were right on top of Chester Lake and wanted to get going. Thus began an intense IDD campaign that lasted longer than we expected. We started with a basic MI+AXPS attack on both Salisbury-1 and −2, settling on a targeted campaign of Salisbury-1:

After the APXS results came in, there was an itch to leave and head towards Shoemaker Ridge or more due north. As my notebook indicates, Squyres (and, well, everyone else), agreed that we should dig deeper — literally. We queued up the RAT and got her grinding. After a seekscan (where it finds the surface), a brush, an MI+APXS set, another brush, and another MI+APXS sequence, we had a nice clean RAT hole:

The Mossbauer spectrometer on Oppy's arm is nothing but a dim light bulb — it's radioactive source has a half life that was selected based on a 90-sol mission, wouldn't you know — but we gave it a try for a few sols, setting it down in the RAT hole.

Pretty pictures and the slew of MI's aside, the Chester Lake campaign was a pivotal point for the MER team. Chester Lake had long-term effects on our rover and our strategic planning that we never planned on, causing some unpleasant hiccups in operations. First, there were the anomalies beyond our control. As with most things for MER, the concepts are simple but they tend to interact in a complex way. Remember that our tactical timeline is on the order of days; what we do today affects tomorrow, directly and drastically. Then, remember that we rely on an entire system of elements and pieces to maintain this tactical timeline. When one element fails, the tactical timeline is altered beyond our control and we have to adjust very quickly. It's not a metaphorical house of cards or a game of Jenga, because that would mean that we literally couldn't operate Opportunity if an element failed. Obviously, this is not the case. It's just a very fragile system. When it works, oh boy does it ever work. When it doesn't, there's a bout of sweating and legwork to get back to normal.

While at Chester Lake, one of the orbiters circling Mars couldn't relay the data that Opportunity had collected because of its own problems. We the MIs, RAT data collection, and MB integrations going on, we needed the data back each and every planning day in order to make good time and get out of there. When this couldn't come, and when we started losing uplinks and downlinks with the Deep Space Network itself due to the orbiter anomaly, things slowed to a halt: we adjusted and added hours on the MB; we used runout plans; we turned single-sol planning days into multi-sol planning days; we uplinked early and often. Sols 2720-2730 were a blur to me: lots of shifts, each of which was unique and different because of the new anomalies presented to me as a TAP/SIE. All told, we "lost" about a week's worth of sols because of the delays in data acquisition and downlink. I use the term "lost" loosely, because it didn't prevent us from collecting more science or stop us in our tracks. 

The second hiccup hit us very suddenly: Winter was approaching. Solar insolation — and its proxy, the wattage generated by Oppy's solar arrays — wasn't looking terrible, but it certainly wasn't looking good. She's a dusty rover and she hadn't had a cleaning in a few months. The engineering team threw together a detailed analysis and projection of the rover's power state for the winter that had an obvious takeaway: find any slopes that faced north and get there. Quickly.

So we boogied to find the Promised Land of Northerly Slopes. Which brings us to Part 5...

100 Sols on Cape York — An Absurdly Brief (Read: Long) Summary (Part 3/8)

Part 3: The Odyssey Crater Ejecta Field — Zinc at Tisdale-2

Sols

~2690 to 2703

"tl;dr" Description

We found this thing that looked like a gold-plated aircraft carrier. So we looked at it… really, really closely.

Highlights from Matt's Notebook

Sols 2692-2693: 

> Some… ahem… involved… discussion at sequence walkthrough, but all is well. VisOdom for the win.

Sol 2694: 

> Today's Secret Woid — "bogy" — and I just checked behind me to see if the computer was about to murder me.

Sol 2695:

> Ecam PUL: "Is that what you said? I thought I heard something else…" // RP1: "You did, but we don't hear those voices."

Sols 2703-2705:

> Planning an escape from the clutches of Tisdale-2 tosol! We'll be back.

Details ("the deets")

I didn't have another shift for some 2 weeks after the first arrival at Endeavour and Cape York. I was in the loop only because I like to walk up three flights of stairs from my office to catch the SOWG meetings. 

Suddenly we had driven to straight into the Odyssey ejecta field and I didn't know left from right. Good thing I'm not an RP. There was all this hoopla about these "Tisdales" and this "Ridout" and, for that matter, why there hadn't been a TAP/SIE Album of the Day in so long.* Tisdale-2 was right in front of us and it was to be our first Endeavour victim.

The challenge presented by Tisdale-2 was twofold:

1) From a few meters back, pick out targets on a very rough rock with interesting features from Pancam imagery, interesting features that were not unambiguously smooth for all the touchy-feely that we'd be doing to it. (With the IDD! With the IDD! Come on!).

2) Actually IDD the damned thing.

One could say that we could have pulled right up to it and taken the close-up Pancams to get ourselves some nicer ideas of good targets, then "bumped" or simply turned to our selected target. Two sols, snip snap done. Right? Nope. One would also be pulling a classic "jumping the proverbial gun" in this case, because that plan would, well, take two sols. We like to take a little bit longer looking at our options in the morning when the downlink rolls in and then nail that drive in one sol. We are a success-oriented team, in more ways than one. Only rarely do we try to get part of the way there and correct thereafter; only rarely do we try to get part of an image or part of an APXS. We only do that when we have to, like when we're restricted by available time in the Martian day**.

The lesson: trust that rover. (Also, the RPs. But, you know, they smell like robots***, so…)

While we planned the approach and ramifications thereabout, the scientists planned their targets. The strategy of an approach drive is, by the way, relatively independent of the final target, since that final target just becomes a parameter somewhere that we change with the click of a mouse. We can get a detailed engineering backbone prepped for when the science team finally comes along and says, "Here, please." For this approach, a VisOdom hiccup (well — feature) gave them an extra day to look and decide. Tack on some tough love for good measure and they decided on two targets for more thorough discussion:

Fake color, by the way. Rookies. I got you good, didn't I?

Clearly, neither was smooth enough to be brushed. Not even the top of the entire rock, with a coating of a composition that we still don't know because we never sniffed at it before moving on, was even close to acceptable. The Rock Abrasion Tool (RAT) is a consumable resource — brushes and grinders and stuff wear out. No point in wasting it here. No worries, because we still had the Microscopic Imager (MI) and APXS (… scatterometer-science-gathering-thingy-mabob) to go at it.

Of course, there's a critical show-stopper for Oppy's arm: A bad shoulder joint has it canted to the left at a few degrees. Also, we don't allow IDD and drive activities to occur without ground in the loop in between them (except for things like the "stow and go"). Combine these two pieces of information and you get the result that if we've approached a target for an IDD campaign, and if we want to choose a new target that's at a different rover-relative azimuth (rotation clockwise or counter-clockwise looking down), it takes two sols — a "bump" or small turn and then the actual IDD work — rather than the single sol to just move the shoulder joint if it actually worked.

Keeping this in mind, the science team chose Target A for surgery. We got an initial taste with the MI and APXS by working in the so-called "workplane" of the IDD, a literal 2-dimensional plane created by the stuck shoulder joint. We took that initial taste, turned it on its head, said it wasn't enough, and did it several more times. Since Tisdale-2 was so rough and rocky on its side, things stuck out. We could reach a few target points with the gunsights of the MI and APXS with a slight roll out of the workplane (roll, pitch, and yaw are independent, children!). All told, we captured a nice chunk of data, a veritable dart board for the ages:

(with MI's overlaid on the second image):

Significant tasty herein.

After less than two Mars weeks, the results from the AXPS were in. At least, in and prepared for a news conference, since we knew everything the day after the data was collected (plus or minus a good downlink with Odyssey and MRO — space only plays nice sometimes!):

Real, actual science.

This tells us that there is an unusually high zinc content in Tisdale-2 compared to the other rocks examined by both Opportunity and Spirit. Not only unusually high, but drastically high — that's a logarithmic y-axis. The one-sentence explanation of this big adult word is that if the change is big on a logarithmic axis, it's huge on a linear axis. Which means stuff. And, remember, stuff means science.

Without much of a fuss, the RPs took the keys and candy-cane'd us out of there:

Next up: Sniffing down a RAT-able target — and finding one that smelled kinda funny.

————————————————

*Actually, nobody cared, which, you know — expected. One of them was a doozy: Wish You Were Here by Pink Floyd. By the way, Newton's 4th Law: You can't turn "Wish You Were Here" down. Universal implosion, black holes of death-inducing doom, trolls who steal your coffee. The usual.

**Example: Last week we couldn't put together a full 2x2x5 MI stack of Boesmanskop at Winter Haven because of lack of time in the day; we got bottlenecked by a few standard engineering things. So, instead, we planned two 2x1x5 stacks.

***Like solder, incidentally. But the good kind, like whatever the kind is that talks, eats, drinks, drives rovers, and makes me smile. I guess this means that I would accept Cylons into our world.

100 Sols on Cape York — An Absurdly Brief (Read: Long) Summary (Part 2/8)

Part 2: Landfall at Endeavour Crater — Cape York and Odyssey

Sols 

~2680 to ~2690

"tl;dr" Description 

We made it! We made it! We made it! Ohhhh look at the pretty!

Highlights from Matt's Notebook

Sols 2683-2684: 

> "This plan is skinny by design." - Ray — interesting, since we're at Odyssey. LIKE, COME ON.

> Holy crap we're here!

> "This is somewhere." — Posted a picture next to my cubicle. Nobody noticed except for my boss, who is, you know, supposed to care.

Details ("the deets")

Suddenly… arrival, Monday August 8, planning sol 2681 (-ish, depending on what one considers "there" to be). We hit the southern tip of Cape York and parked next to Odyssey crater, which was a landmark close to the non-specific "Spirit Point" locale that identified our arrival:

"But, Matt, Spirit Point isn't a point." Don't care.

"Hey, isn't that your blog's background?" Perhaps, but the demon in me says it's Photoshopped.

Of course, that second image confused everyone in the wide world outside of the MER enthusiast: With headlines like "Opportunity Arrives At Giant Endeavour Crater," you might expect the panorama that actually showed as much of Endeavour as possible, but instead most folks passed around that image of Odyssey, which is in the 10-15 meter diameter range, and said, "That's not that big. I'm already bored."

We had to throw on the brakes, hard. Suddenly, drives were precisely targeted and the entire mission changed. At least, it did from my perspective — the only Oppy I ever knew was the one that silently trekked hundreds of meters across the Meridiani at a time. A little poke at a rock here, a little imaging of a shallow crater there, nothing much. Then it was wham, we're back in this science collection gear that I'd never seen before. We weren't driving just to drive, or IDD'ing just to IDD, but we were doing those things to do other things. 

(And, honestly, it made the science team's role that much more apparent to me. It's an obvious thing — you know, we're there to do science in the first place, Matt — but I don't get obvious things very well. In the Meridiani, I looked at them as if they were the last remains of the mission that used to be; now, they were front and center. They owned the mission.)

The Odyssey Crater was the first thing that captured our attention:

What, you don't have your red-blue glasses? What is this, amateur hour?

And, to the east, towards the inboard side of Cape York and Endeavour itself, a nice ejecta field from Odyssey's creation:

Stu's black-framed images make me look classy, don't they?

The goodies — those smectites and phyllosilicates — were located somewhere in the middle of Cape York, or north of our "entry" point on to Endeavour. At least, according to orbital imagery and remote sensing. We shirked the direct path to these targets mainly for several reasons:

1) Cape York dips down into Endeavour on the inboard side and instead of poking our head over the proverbial edge didn't seem to be a very prudent way of attacking Cape York as a whole.

2) The true traversability of Cape York, especially on its inboard side towards the center of Endeavour, was unknown until we had some imagery from the rover itself. Our RPs took a look at Cape York and identified two paths: one that would have approached from just north and west of Odyssey, and the one that we took, from the south side and working northward to capture as much of Cape York as possible.

I've illustrated these paths on this perspective Google Mars shot of Cape York that I stole from Stu near sol 2680:

Conveniently, "A" stands for "actual" and "B" stands for "backup". I will pretend I knew this before I made the annotations to the image, and you will faithfully affirm this delusion for me.

Remember, these were notional only, meaning this was a strategic plan. As we'll find later, Path A actual curved back north much sooner than indicated here. In any case, the immediate advantages to path "A" were that nice ejecta field from Odyssey for analyzing and poking and sniffing. Odyssey not only had its own story, it also exposed the internal bits of Cape York itself. Another Google Mars shot from Stu's blog gives us an idea of where we stood:

Right in our gunsights was Tisdale-2. On approach just a few meters to the southwest of Odyssey (and its large, perched rock, Ridout), here was our view this aircraft-carrier-looking beauty:

If you still don't have your red-and-blues, don't come back until you do.

But, wait, Tisdale-2 was a whole new treat, a whole new taste, the start of this new mission. So, just as this "phase" of the Endeavour Campaign was short — roughly 10 sols by my arbitrary estimate — so will this part of the story be! 

100 Sols on Cape York — An Absurdly Brief (Read: Long) Summary (Part 1/8)

Just as you might expect for a young-gun Generation-Y'er, I'm wired. I use my iCal, Mail, and everything else in my Macbook to manage my world. ("Manage the crazy. Bring out the talent.") I need things to be organized, so rightly placed and micromanaged that it would make a normal person wonder how (or why) I'm not on Ritalin. However, I have one holdover from the olden days. That holdover?

The notebook.*

Don't get me wrong: I am a fan of TextEdit and other flat-text, note-writing programs. Who needs all that markup, right? But there are so many places to put files that you forget not only what you named the file, but what's in it. With a notebook, it's all right there, ready for consumption, with perhaps a little page flipping.

I have several notebooks for work. First, one for all my multi-mission work — you know, the Juno's and MRO's of my world. It's got scribbles and notes and it's a total brain scatter. I love it. Organized, but not. Second, one for logging my days. Like a work journal, but abbreviated and totally half-hearted. I tend only to log the more important days, because those days are usually filled with actual work and I have less to write ("7am: MER shift. 7pm: Sequence model development for MSL.") Third, one exclusively for MER. I never kept a MER notebook until I felt it was important enough. That time, that crossing the threshold of "important enough," was when we hit Endeavour Crater. Rightly so, the notebook is named "The Endeavour Campaign." 

This notebook serves the purpose of reminding me of what I did on each of my shifts — new tricks, bug fixes, engineering tidbits, that sort of thing. I never thought it would turn into the monster that it did. A few weeks ago, someone asked me a question to which I had the answer in my notebook; I couldn't remember where it was, so I started flipping the pages. "Geez, it's right here, gimme a sec… Hang on, I know I'm close… Man, I've written a lot…" 

As it turns out, "a lot" is about 100 pages in 100 sols.

Holy crap, we've been here 100 sols!

To drive it home further, a former-colleague-and-classmate-now-new-colleague-and-MER-TDL-in-training-and-drummer-in-my-Sunday-jam-sessions friend asked me today, "So I've seen all the news stories about the Gypsum find, but nothing yet from your blog. What gives?"

Well, trees give. They give very easily, in fact. He understands my pain, though: we both experienced 50 hours without power at our respective houses. Even so, this blog has been empty for most of December. What else has been going on? 

This post, is what!

I've been prepping this post for a few weeks. I have this uncanny ability to steal pictures from the various Cape York UMSF threads and Stu's blog. By steal, I do mean borrow with credit (Stu said I could! I swear!). I also have this uncanny ability to be incredibly wordy. So, onward!

(Courtesy Dr. Awesome XVII)

My intent is, as always, to provide context and insight into what happened these last three months. You can expect a little chaos here: 8 parts, each with the intent of informing people who aren't so in the loop as some of us are. The purpose is to be a summary, so if you know what happened, don't spoil it you crazy goons.

(Remember: For full-size images, click them!)

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Part 1: The Approach to Endeavour Crater

Sols

[forever ago] to ~2680

"tl;dr" Description

We drove for, like, ever.

Highlights from Matt's Notebook

[No notebook! Boooo!]

Details ("the deets")

About 1000 sols ago, the Opportunity rover was commanded to drive away from the Victoria Crater. Having expired her manufacturer's warranty nearly 20 times over already, the team said, "There's this large-ish hole in the ground, way over there, so let's go. Who knows?" 

When describing this new mission for Opportunity, Project Manager John Callas could make no promises for when we'd arrive at Endeavour. It was 19 kilometers away (not quite as the bird flies) — more than Opportunity had already driven in its 1700 sols on Mars. And there was all this stuff in the way, like the Purgatory dune field and small craters and rocks everywhere. His — the team's — best guess was, "When MSL lands in 2012. Maybe." Our target was this little guy on the west side of Endeavour, named Cape York:

(Ignore the red circle on the second image.)

For an idea of the size of Cape York, check out Stu's post. That third image is a perspective view looking roughly north, giving you an idea of how it bends in towards the center of Endeavour. Spirit Point was the destination, the small Odyssey crater being a nice landmark for us to shoot at.

Somewhere in that journey, near sol 2310, I joined the MER team fresh out of school in Colorado. From the start, I noticed this curious little countdown meter in the LTP (Long Term Planner — someone who represents the SOWG) reports when the most recent traverse was shown in aerial imagery from the MRO spacecraft. This countdown meter counted down the distance from Victoria Crater to Endeavour Crater. The number was in the mid-40%'s when I joined, and that last 55% was a seemingly insurmountable task. We chipped away, little by little, and suddenly that number was 80%… 85%… 90%… All we would see in the LTP reports were images like this:

Very tantalizing. "What's it really going to be like when we get there?" we found ourselves asking.

Then we did this whole thing: 

And we did it a year ahead of schedule. Neat.

To capture the journey, I spent a few hours going back through every LTP report since sol 2310 and picked out a traverse roughly every 10 sols to build a "distance traveled" plot. (The maps posted at the MER website don't have the detailed Ohio State maps with the countdown meter as often as I need them. The information could also be found in the Google Mars maps that Stu and company make, arriving at the same answer.) This plot? Oh yeah, it's right here!

Several things here: 

> I layered in text annotations of targets and key events to give us some context.

> The left-hand side (blue line) is the percentage from Victoria to Endeavour ("V2E") according to the Ohio State traverse maps. 

> The right-hand side (green line) is the distanced remaining, derived from the V2E line.

> Not all meters are created equal. More on this in a minute!

Cool, right? ("Right!") 

The obvious trend in here is rough, linear progress. The other obvious trend is the long stop at Santa Maria for an extended science campaign and Solar Conjunction, or when the Sun gets directly between the Earth and Mars, from December 2010 through February 2011. Also, note the other key events. My favorite is what I'm calling the "Squyres Week," when Steve Squyres came in on a Monday and said, "I'm SOWG Chair all week and I want half a kilometer by the end of the week." Sure enough, that week's Mission Manager report proudly toted nearly 600 meters of drive distance in 5 planning days. 

Now, some explaining is in order. The distances reported in the were based on the so-called "Pink Path," which changed as we approached Endeavour. Therefore, I say the phrase "not all meters are created equal." Meaning, a given meter of progress towards Endeavour is not the same as another meter of progress at some other point in the journey if the Pink Path changed. Which it did — a lot! The arrival point was always Cape York but the twists and turns between Victoria and Cape York changed quite a bit.

We get a notion of "speed" (literal meters per sol) of the rover by looking at the slope of the "percentage progress" line (or the negative of the slope of the "kilometers left" line). We see that before and after the long hiatus at Santa Maria the slopes of the line is generally linear and about equal. We were just a little bit more of the "PEDAL TO THE METAL, BABY!" persuasion after Santa Maria, so why does it seem we did the same meters per sol as before Santa Maria? Because the Pink Path got longer! A given meter of progress after Santa Maria was not the same as before Santa Maria, because the SOWG got together and picked all sorts of cool little targets along the way.

(A way around all of this is to use actual drive telemetry — actual distance traveled every sol — to get a better notion of speed. But that's proprietary and painful. No thanks! Plus, the "V2E" count up is a little more fun to look at.)

Right. So. Speed. (I almost typed "velocity", but, you know… it's not that.) Why don't we just take a look at that directly? Ok!

Indeed! The speed shows up a little more obviously larger in this figure. There are two trends: first, an increase in speed — an increase in us wanting to get to Endeavour; and a cyclical "up down" pattern along this linear increase in Endeavour-wanting. That increase in speed was enough to overcome the effect of the Pink Path increasing in length! That's fast.

But, why is there a second trend? Why does it wobble? Shouldn't it be prettier?

No! Of course not! That pattern is, nearly precisely, the cycle between Nominal and Restricted planning! Remember: in Nominal, we can plan a drive every sol because the timing of uplink and downlink sets us up to know what happened before planning tomorrow; in Restricted, we can't plan a drive every sol — more like every other or every third sol — because we don't have "ground in the loop". I found this fascinating, if not completely ultra cool.

(Also, ignore that noisy large bit at the end. That's an effect of the Pink Path changing more wildly and our indicator of "progress" breaks down. The rest of the values before that noisy bit square nicely with approximations reported daily at our tactical meetings -- "assuming 65 meters per sol" was a common phrase towards the end!)

Along the same vein of "progress" indicators, here's a series of four high-resolution Pancam images of Endeavour from sols 2410 to 2681 (skewed towards the end of the timeframe because I'm lazy):

Then we have the famous Navcam Movie, another indicator of progress for the entire journey. And, as noted in the progress plot above, there was the appearance in the LTP reports of the vertically-exaggerated "Endeavour 'Fall Away'" GIF that I found on UMSF:

Hey, you know, that picture was an event in itself to me because suddenly Endeavour had opened up, like HEY EVERYBODY, EVERYBODY HEY. Simply stunning.

So what, right? We went a long way and we have all these great things telling us about the journey. Then? Then what, Matt? Is there something to the end of this story?

How about this: You all quiet down and stay tuned for…

Part 2: Landfall at Endeavour Crater: Cape York and Odyssey

(Tomorrow, maybe!)

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*Not the movie. Oh god, please not the movie. Anything but the movie. I kept this phrasing because it feels so, I don't know, poignant. Or something.

No electrons

Currently blogging from a Starbucks because of this (at my house):

And this (at JPL):

There's currently a major lack of electrons (read: electricity [read: internet]) in my part of Pasadena, and I probably won't get power back until Monday.

Until I get my damaged house in order and find the trash cans that blew down the street somewhere, I won't be able to get back on the blogging horse. 

But, hey, I've got a goodie for you. In the post queue:

100 Sols on Cape York

It'll be a good one. I promised Stu that I'd have the post done a week ago, but then I forgot that we had to launch MSL and, well, you know how those things go.