Captain's Log, Supplemental: A Final Word

So that's it -- that's where my life got too complicated to continue transcribing what happened each day on MER. It's been a blast to revisit MER's early days -- it all flows by so fast when it's happening, and it's been a treat to get to live it all over again.

And, of course, to contemplate how my life has changed in those years. Deaths, divorce, new beginnings -- the rovers have been there to anchor me through ups and downs. No matter how bad things got, I'd go to work, reach across a hundred million miles of emptiness, and move something on the surface of another world. It was always magic. I can't imagine what it would have been like without my twin girls, and I'm deeply grateful that I haven't had to find out.

I'll try to write another blog like this one for MSL, though of course you might have to wait five years to read it. (Discussions with JPL's media folks will begin soon.) In the meantime, whatever happens with that, you can always follow along with MER at the MER home page, and of course I'll continue spouting off from time to time at my Twitter and Google+ accounts.

As I always say, it's one thing to drive a rover around on Mars -- that would be cool, but the real fun for me is that I get to take everyone in the world along in the back seat. This blog has been another way to do that, and I'll miss it now that it's gone.

Thank you for sharing this adventure with me. Thanks for reading.

Opportunity Sol 1138 (Spirit Sol 1158)

It couldn't be a better day to be on shift with Tara and Julie, because we have a visitor. The visitor is Brenda's surgeon's daughter, Amanda. She's graduating from high school and is interested in robotics.

According to Brenda, Amanda has the silly idea that women maybe can't do robotics (even though she's into the field herself), so it's fabulous that she's here on a day when she gets to see two women drive the rover -- 35m toward the dark streak. And not just any two women -- two young, very bright women, who give her lots of terrific advice about college and grad school into the bargain.

Squyres always says this is the best thing we can do: however well we've done, we must inspire the next generation to outdo us. Do it, Amanda.


Opportunity Sol 1136 (Spirit Sol 1157)

We come in all hot to drive to the dark streak east of us -- and are sorely disappointed. We had a joint-1 stall in the IDD sequence yesterday. So today turns into a less exciting one; we just have to redo most of yesterday's sequence. But at least it's easy, and it's OK to have an easy one now and then.

Sharon makes time to shadow part of the day again, and delivers her first sequence ever!


Opportunity Sol 1131 (Spirit Sol 1152)

We had a perfect bump to the rim yestersol, and we're now ready to take the first eye of our long-baseline stereo here. Then, later thisol, we'll creep 5m along the rim to the position where we'll take the other eye.

It's rare that we drive along the rim like this; mostly, we drive up to the rim, then back away slowly and reapproach somewhere else. I muse about this out loud to Sharon, who's able to put aside a little time to shadow today, and she has a great idea: let's make a movie!

We manage to sweet-talk the science team into this. It actually doesn't take a lot of effort -- they see the outreach potential as much as we do, and, hell, they think it's a cool idea themselves. (Larry Soderblom's response is, "Five megabits, on the scale of 600 megabits for the weekend? Sure!" He pauses for a second. "Uh, but let's stop it there." He's been doing this a long time, and is wise in the ways of the world.) So we set up to take images about every meter or so, and we're off.

Since these images have no particular science or engineering value, we prioritize them pretty low. They'll probably take weeks to come down, maybe a month or more. But when we get 'em, they'll be cool.

Courtesy NASA/JPL-Caltech. Since Blogger doesn't seem to like animated GIFs, here's our rim-crawl animation from that sol. Awesome!


Opportunity Sol 1130 (Spirit Sol 1151)

Now this is unusual. Squyres is normally the most committed, gung-ho guy in the room, after Yours Truly. But today he gently asks if we can do whatever we can do to make it possible for him to leave early.

"It's the first beautiful day here since ... forever," he sighs over the telecon. "I got my cycling gear, I'm ready to hit the road."

"You want to just do a remote sensing sol -- no bump?" Colette teases him.

"I wouldn't go that far," Steve says. "But, whatever you can do."

We work through lunch. It saves half an hour. Anything for Steve.


Opportunity Sol 1126 (Spirit Sol 1145)

... and I'm back to the other side of the planet. Today it's a drive -- a short one, but still. We're going 10m blind and another 15m on autonav, around Victoria, toward the (misnamed!) Valley Without Peril.

It's a simple drive, but it's a complicated day, because it turns out we've had uninvited guests on our Meet-Me lines for some time. For years, since shortly after the end of the nominal mission, we've been using teleconference lines to gather the far-flung ops team -- engineers mostly here, scientists here and across the country -- and coordinate our planning. And we just leave the lines open all day, so we can ask each other impromptu questions and whatnot. Well, these are the same phone numbers all the time, and they don't have any access controls for security (duh), and some dumbass included the phone numbers in a presentation that was posted on the Web several months back. (But don't blame him: some bigger dumbass in JPL's Document Review signed off on it.)

This is a huge problem for a number of reasons, the most serious of which is that we discuss all kinds of ITAR-sensitive information over these lines. Under the ITAR law -- that stands for International Trafficking in Arms Regulations -- a spacecraft is a weapons system, so exporting technical data about it is exporting technical information about a weapons system. As far as the law is concerned, discussing certain technical details about MER is exactly the same as a similar discussion about, say, the Patriot missile system. If we continue, knowing what we now know, we can get shipped to federal prison. So we have to scramble to set up new phone lines, and get the new numbers to everyone who needs them (without disseminating them over the old lines, for obvious reasons) ... oy, such a mess.

While they're setting that up -- and we're still on the old lines -- Squyres asks a bunch of obvious questions, like how long this has been going on. We don't know a lot yet. "You know what I'm gonna do?" he says. He doesn't sound mad, but he knows how serious this is, how much trouble it could bring to all of us. "Tomorrow I'm gonna call in on the old line, and start out as if I'm starting a SOWG meeting ... and then I'm gonna stop, and I'm gonna have a talk with these people."

"First you should tell them about the great alien artifacts we found, Steve ...." I pipe up.

You can just hear Steve burying his head in his hands. "Somebody smack him," he groans.

[Next post: sol 1151 (Opportunity sol 1130), March 30.]


Spirit Sol 1144

I like Torquas, mainly because for some reason it's easy to create catchy sequence names incorporating it. "Tool Change on Torquas" is today's sequence -- sounds like it oughta be an Edgar Rice Borroughs short story.

Like most tool-change sequences, it's a pretty simple one. And it was already written, yesterday, by someone else. But it's got a weird little quirk -- nothing wrong, just unusual -- and Ashitey and I are curious about it. Sometimes these little quirks don't mean anything, and sometimes they're a warning that there's something yesterday's team understood and we don't. So we call Paolo and ask him to explain it to us.

Turns out, it's nothing -- just one of the newer kids building sequences, and not quite on the same page with the rest of us. But Paolo's tickled that we asked him: "Last week, Jeff Biesiadecki asked me to review a drive sequence. Today, Ashitey asked me to review an IDD sequence. Only thing that could top that would be for Steve Squyres to ask me a science question!"


Captain's Log, Supplemental: All Good Things

Just to give y'all a heads-up ... I wrote these blog posts contemporaneously with the events they describe, five years ago as you read them. At some point, though, I simply ran out of time to keep up. That point was five years ago, early next month. So in a couple of weeks or so, a few posts from now, the entries will run out, and this blog will see no new posts after that.

Happily, of course, MER goes on ... and on and on and on. Five years after these events, we're a rover down, but Opportunity continues exploring Mars. Just today I heard a presentation on how the radio-science work she's doing over the winter (her fourth Martian winter!) is helping to pin down the internal structure of the planet she's made her home these eight years and counting. And Spirit still continues to make science news and to contribute to graduate students' Ph.D. dissertations -- and continues to inspire us all to do more and better than we ever imagined we could.

In a couple of weeks, then, I'll say some farewells. But we're not there just yet. For now, this journey continues, just as Opportunity's does.

Spirit Sol 1141

Today we're headed to a chunk of rock called Torquas -- from Edgar Rice Burroughs's Mars novels, continuing the long-overdue theme of Mars-related science fiction names. Torquas is ahead of us and to the right, so my plan is to push forward, turn to the right, and head up to it. But a short chat with Ashitey and John convinces me that I'm not using this vehicle's mobility to best effect: I should just twist around the right front wheel toward it, then push forward as far as I need.

And this way lets me name the sequence "Twisting Toward Torquas." So it's definitely a winner.

So we get everything done, and right at the end of the CAM, just as we're wrapping up, we get bad news: New Horizons stole our uplink! And this isn't the first time this sol's uplink has been stolen -- MRO stole it last week, but we were able to carve out an hour when they were occulted. But now NH is in safe mode and wants that hour.

Oh, how have the mighty fallen! We used to beat up other projects and take their uplinks, as well as their lunch money, and now look at us. Well, I suppose we're merely getting our just deserts. But, as so often with this project, the team's rapid and highly capable response saves the day: Cindy, Byron, and others start running through possibilities, and end up working out a way for us to use a different station for the uplink. This window's only five minutes, but we're able to squeeze our sequences into it without modification. Go, team!

[Next post: sol 1144, March 23.]


Spirit Sol 1136

Let's see, we're back on Spirit now, so we're driving around ... oh, yeah, Home Plate! Or, rather, Mitcheltree Ridge, where the science team thinks outliers of Home Plate material are to be found. Today Terry and I are driving her over there.

And we're doing that a little more carefully than usual. The original path we'd planned for her would have taken us through a scattering of 10cm rocks, which we're nervous about dragging her anchor through. But then we spot an alternate destination that requires less turning and offers a clear path -- so there we head.

We're also nervous about something else. Yesterday's drive ended in some softer soil, and we found that she's turning more sluggishly in this stuff. With shades of the rover-eating Tyrone soil expanse haunting our memories, we make some very conservative choices. The soil seems to change back to a friendlier consistency a couple of meters away -- but it's so hard to be sure of these things, when all you have are visual cues. The absence of little ripples is our hint that the soil turns firmer.[1] It's just an educated guess, but sometimes that's all you have. So we argue a bunch, make some tweaks to the sequence, cross our fingers, and send the sequence to Mars.

[Next post: sol 1141, March 20.]

[1] This hypothesis was later confirmed by the science team. We'd noticed the pattern, but at this time we hadn't thought to ask them.


Opportunity Sol 1107 (Spirit Sol 1128)

The bump to the rim of Cabo Corrientes went well. The drive currents on the RF wheel were a little high, so Paolo recommends we do this bump backward. I believe the concern about Opportunity's RF wheel is overstated; we're seeing higher currents when we drive because the stuck steering actuator makes that wheel fight the others, and this is marginally detectable on outcrop or very hard-packed soil such as we have under us now.[1]

But we like erring on the side of caution, and anyway driving backward is natural thisol: the turn is shorter in that direction, and counterclockwise (and hence won't scoop material into the RF wheel) to boot.

All in all, it's a laid-back day. I can certainly say that the 4m Opportunity is driving today pales in comparison to the more than 42km -- that's right, km -- Ashitey ran the other day. 42km is about 26 miles to you and me, a marathon. He's not exactly trying to hide it; he's actually walking around wearing his medal. Well, hell, if I were Ashitey, I'd be doing the same thing.

The only thing that could make today better would be if Frank were back from paternity leave. And he is! Even though he won't be driving the rovers again for a while -- maybe never again -- he's going to stay connected via strategic work. And, heck, he's a great guy; it's just nice to have him back.[2]

[Next post: sol 1136, March 15.]


[1] Nope. As usual, Paolo was right: this was a very early sign of what developed into fairly significant trouble with that wheel. To this day, we don't know what's wrong with it, but as long as we drive Opportunity almost exclusively backward, the problem stays under control. Once again, let us all bow to Paolo!

[2] Happily, Frank eventually made time for MER again in his schedule -- and for MSL. He's the Endeavour exploration lead for Opportunity, and he'll join me on MSL as a rover driver as well. Life just keeps getting better!


Opportunity Sol 1105 (Spirit Sol 1125)

It's a straightforward day in the Land of Opportunity as we bump all of about 8m to the rim of Cabo Corrientes, setting ourselves up to take the first eye of our long-baseline stereo image here. It's kind of a yawner, as these things go, since I have a shadow (Tara) doing all the real work. I kinda miss the days when I actually got to drive the damn rover once in a while.

I do have one clever idea that makes me feel glad I showed up. Our post-drive imaging is a 3x1 NCAM, which is way more than we really need to support the 4m bump we'll do next. We pretty much know where it'll go, since it has to be perpendicular to the wide-baseline stereo images, so we don't have as much uncertainty about the drive direction as a 3x1 NCAM provides for. My moderately clever idea is to take a 2x1 in the likely direction and a 1x1 in the opposite direction, just in case we realize there's not enough room one way and we'll have to go the other way instead. Both directions are perpendicular to the imaging direction, so either one could potentially serve the purpose.

OK, maybe "clever" is overstating the case. I'm just trying to justify my existence, okay? Work with me, here.

[Next post: sol 1128 (Opportunity sol 1107), March 6.]


Opportunity Sol 1101 (Spirit Sol 1121)

It's a busy day. We start off with a MB soil-touch test, just planting the MB on the soil to see if the contact switches trip -- not that there's anything wrong with Opportunity's MB, but this exercises most of the same software path that's a possible culprit in the Spirit MB contact problem. Whether we see the same problem on Opportunity or not, we'll help narrow down our suspects.

After that, we're driving, putting some distance between us and Cabo Corrientes. The first part of the drive uses Visual Target Tracking, a new R9.2 flight software feature we're still checking out. After that, it's a cool 30m of autonav toward the Cape of Good Hope. You know, the one on Mars, not the original.

We need the help of the main VTT developer, Won Kim, to be sure we're doing today's part of the VTT checkout right. I am quickly reminded that research guys aren't used to ops -- they don't have the sense that you gotta do stuff and make decisions right now because there's a tactical deadline, and if you miss it, you blow a sol. So they aren't in the constant hurry that characterizes the rest of us. They dither. They optimize. They tweak.

They drive me nuts.

So I put him with Terry. Which isn't mean; it's a brilliant (ahem) solution because Terry himself comes from that world but understands this one, so he can speak Won's language and still get things done on time.

And it works out just that way. Despite some early delays, we're mindful of the hard 14:30 deadline that Matt Keuneke spells out for us, and we meet it with room to spare. Hell, we're ready at 14:00. It's almost embarrassing.

Since we have all this extra time, maybe we can afford to dither, and optimize, and tweak. Or, come to think of it, let's not.

[Next post: sol 1105 (Opportunity sol 1125), March 3.]


Spirit Sol 1116

Today we're continuing to follow our months-old tracks back toward Home Plate. Our plan had originally been to skirt this little ridge about halfway along today's drive path. But then I went hunting for any old images we had of the ridge, to see what it looks like on the far side, just in case the far side hid a gimpy-rover trap.

It turns out we have a fantastic, close-up image of it -- as we were running for McCool, shortly before the RF wheel failed, we stopped right in front of it at the end of one drive. So we're able to look closely, decide that the slopes and pebbles are all benign, and commit to going over it rather than around.

That still leaves us with another decision: are we going to go north, along Home Plate, to image its east face? Or will we go west, toward the on-ramp? Or, maybe, will we compromise, heading west past the debris field and then heading north? We won't be doing that north-or-west drive today, but we need to set ourselves up so we can do it tomorrow. Since it's still a matter of some debate among the science team, however, we compromise, aiming instead for a point where we'll be able to choose either path on the next sol.

I used to not like compromise. But when it gives other people badly needed time to make up their minds, and when it makes your own life simpler in the process, well, there's something you can say for it.

[Next post: sol 1121 (Opportunity sol 1101), February 27.]


Spirit Sol 1114

Damn, we nailed that drive. The rock's right in front of us, right smack dab where it's supposed to be, ready for us to give it a working-over with the IDD.

But will we? The IDD diagnostic we did on 1109 gave us troubling results -- no news, which in this case is bad news. We tried touching the MB to the soil, and we got nothing. The images and telemetry agree that there was simply no contact.

Now, that's weird. We really should have seen contact. This makes no sense.

Whether it makes sense or not, the consequence is that we can't rely on the MB to sense contact now.[1] That means a lot of IDD work has to get put on hold -- we can't place either the MB or the APXS, and we can't touch soil at all. It's RAT, MI, or nothing. Indeed, it's worse than that. Since we're not sure what the failure is, until we've done more analysis we're not sure it's safe to move the IDD at all.

The question for the science team is whether they're willing to wait here until the analysis is done, or move on. It's a painful choice, since we worked so hard to get here, but they decide to take pictures and move on. With stolen uplinks, upcoming restricted sols, and other issues, if we decide to stay here at all we'll be here for a week, and they -- by which I mean Ray -- are not willing to spend that much time for this observation.

He puts it well at the SOWG meeting. After a good summary of the IDD situation, he says, "The main reason for coming to Bellingshausen was to do remote sensing on Troll-like outcrops. We've done that. We should drive on and do continued IDD checkout as we go."

That argument carries the day, so we're on the road again. It's sad to leave Bellingshausen, since we were so proud of the drive, but that's the game.

One thing that made the drive so impressive was the damage it did to the terrain. With one wheel stuck, we chew up a lot of soil just turning around, and the previous turn was a 180. So the RHAZ from today was quite a sight, with a huge swath of Martian topsoil shoved around by our anchor.

So impressive is it that Squyres calls in to ask us about it. He's teaching the Intro to Planetary Astronomy and Exploration this semester at Cornell -- who better? -- a class of about 250 students. "Every day I give them about a 5-minute rundown of what the rovers have been doing," he says. "It's kind of a fun way to kick things off. Today I showed them that image of the churned-up soil and all the back-and-forthing from the downlink report."

So at least it'll be good for something.

Today is an RDO, meaning people who work JPL's newly introduced 9/80 schedule have the day off.[2] As a result, lots of Lab services are closed; in particular, only one of the cafeterias is open. Then, just a few minutes into lunchtime, there's an announcement: there's been a fire in the cafeteria. Nobody's hurt, but they have to close that cafeteria. Project Manager John Callas, however, buys everybody pizza from Round Table. Our hero!

I blame the disconcerting announcement of the fire, and my concern about the safety of the cafeteria personnel, for what happens later. For the first time since I don't know when, we catch a real error at the final walkthrough and have to redeliver. (Unusually, Sharon's here and watching. "It's probably my fault," she grins.) The problem was that our drive backbone sequence didn't check whether its helpers were on board, and if they failed to make it to the spacecraft, a variety of bad things might have happened. Annoyingly, I'd briefly thought of this problem earlier, but I failed to write it down, and it went back out of my head by the same door it came in, I guess.

So we have to walk through it all again, and when the time comes to do that, Rich Morris -- a Mission Manager and an RP wanna-be -- asks if he can do the walkthrough.

Ashitey and I glance at each other, then shrug, intrigued. "Go for it," I tell him.

He does it! And he does a pretty good job of it, too.[3]

[Next post: sol 1116, February 22.]

Courtesy NASA/JPL-Caltech. Can you believe that when we landed on Mars, I felt bad about every imprint I caused the wheels to leave in the soil? And now look what I'm doing to the place. You'd think I lived here.


[1] This is because the MB instrument on the end of the arm has the only contact plates designed for sensing contact with the soil. The APXS and MI, in different ways, can sense contact with hard surfaces -- though the APXS's way of doing that has been broken for a long time anyway. But only the MB can sense soil contact.

[2] In case you don't have this at your workplace: 9/80 means you work 80 hours in not in the usual 10 days but in nine, by working an extra hour for eight of those days. Then you get a day off every two weeks -- in JPL's case, you get every other Friday off. Unlike most of the Lab, MER stayed on the standard, 5/40, schedule. I am personally on something more like 5/80. :-/

[3] So it's a shame Rich is no longer with us: he killed himself last year. This is the first time I've been able to see, up close and personal, the effects that a suicide has on the people who are left behind -- and I know it's much worse for his family than for his co-workers. Rich had a number of good friends, both on MER and off MER, who would gladly have lent him the perspective on life that perhaps he lacked. If you're in a similar situation, find a person in your own life who will give you that perspective, and make sure you get it from them. Please.


Spirit Sol 1109

I'm happy, so happy. There's a MER science convention in town, and the science team is actually here in the room with us. Today we're joined by "PANCAM Emily" (as we call her, to distinguish her from "Mission Manager Emily"), along with a couple of other usually off-Lab science team members.

Others flow in and out through the day, including Rob Sullivan, whom it's always a great pleasure to talk to. And that's not only because he makes a point of profusely thanking the RPs for all of our hard work, and enthusiastically sharing the science results he's deriving from the observations we're helping perform. Okay, that doesn't exactly hurt, but mostly it's just that he's a super-nice guy.

Another side benefit of having the scientists in town is that they give a science update/briefing for the engineering team. Except, of course, for those of us on shift -- such as yours truly. It really sucks to miss it, but if you have to miss it for something, it might as well be this.

But there's one part I refuse to miss. Word reaches us that one of the scientists brought in an actual Mars rock -- a couple of them, really; ancient Martian meteorites that have been found here on Earth. The moment I hear about this, I zoom upstairs to get a look. Objectively, they're kind of disappointing, just a couple of chunks of granite-like stuff. But the idea that I'm holding a piece of another world in my hands is plain thrilling, even if I do have to wear latex gloves to do it.

To my astonishment, I literally have to drag Terry and Ashitey away from the keyboard to get them to go up and have a look themselves. ("Guys," I point out, "the tactical timeline is important, but this is a once-in-a-lifetime opportunity. Do not miss this. You will kick yourselves if you do.") As it is, Ashitey gets distracted by Jennifer Trosper and never gets around to holding the rocks -- as he sheepishly admits to me later -- but Terry makes a point of thanking me.

Despite all the distractions, we get through our sequencing without too many hiccups. And it's a complex day, with both IDD and driving: we're doing a test of the MB contact switches, then spinning (well, lurching) around so we can examine the Bellingshausen outcrop we dragged ourselves over to on a previous drive. The drive sequence is awfully complex, but we're getting better at these drives, forming tested and reusable pieces to build them out of, so that they're not quite as bad as they look.

Squyres is one of the visiting science team members, of course, and when he stops in for the final walkthrough, he can barely contain himself. "If you'd done a drive like this during the nominal mission, the Mission Manager woulda thrown you outta the room!" he cackles.

Since he's here, I take the opportunity to ask him about, well, Opportunity. (And about the HiRISE cameras, which seem to be showing some kind of premature degradation in the optics or electronics. He's glum about that.) The plan for Opportunity, Steve says, is tentatively to visit two more promontories, and then we go in.

"At Duck Bay?" I ask him.

"Maybe not. We can ingress wherever," he says. "At Endurance, we had the rule that we could only go in if we could prove we could get back out. Here we have no such restriction: the project is OK with it if we're unable to egress."

Well, the project might be OK with it, but I'm not. Now's not the time to make a point of it, but we're not going in there unless we can get out again.

Speaking of getting out ... it's Valentine's Day, and Sharon has decreed that we are not to remain here past 5 PM. She shows up about 20 minutes before that so she can start glaring at everyone a little early.[1] Despite a late start, a drive plus IDD on the same sol, and a multitude of distractions, we make it. Barely -- but we make it.

[Next post: sol 1114, February 20.]


[1] Just one of the many things that made Sharon probably the best boss I've ever worked for.


Spirit Sol 1103

Hot damn! She can still dance!

I can't sleep, of course, so I get up and check out the downlink. It takes me a couple of minutes to realize that the reason it looks funny is that she made it, and then some. The reason I don't see a big churn of soil right in front of us is that it's at the other end of a long drag mark, meters away now.

Not only did she turn completely around, but she also managed to complete nearly the entire bonus drive.

Baby, I'll never underestimate you again. That's a promise.

What do you do with a rover this feisty? You give her a bigger challenge. And that's what we're up to today. Continuing to follow her old tracks back toward Home Plate, we plot a course that slaloms backward -- northwest, west, northwest again -- for a total of 11 meters or so. Part of that, again, is bonus driving; we'll take it if we can get it, but we don't expect to ... wait a minute, what did I just say? I'm not doubting you, baby, I promise!

For all that, it's not a particularly complicated day. We've been developing a reusable library of sequences to help build chunks of the drive, and we're able to use them to build most of the drive today. This confirms that the Observer Curse continues. (The Observer Curse is this: when I bring in a new RSVP developer to watch the process, as I've done today, it always turns out to be a fairly simple day. It's good that this leaves us time to answer questions, but when it's not a pressure cooker, it's hard for an observer to appreciate the need for rapid, solid tools. Oh, well. I'll have to communicate that need to Bruce-John[1] some other way.)

And by the way, I learn at the SOWG meeting that today is the first day of Martian Spring. No wonder Spirit is in such a good mood! She's feeling her oats and rarin' to go.

And if we don't come in tomorrow and find that she's gone the whole 11 meters, I'll eat my hat.

[Next post: sol 1109, February 15.]

Courtesy NASA/JPL-Caltech. Looking back at the long right-front-wheel streak we left on this past drive.


[1] John Baldwin was a developer we brought in for a while to work on my part of the RSVP software, RSVP-RoSE. Since we already had a John (John Wright), we called the new John "Bruce," or sometimes "Bruce-John." It's a reference to a Monty Python sketch. And I remind you that there is no Rule Six!


Spirit Sol 1102

We didn't see the MB's contact switches trip on Puenta Arenas, after not seeing them trip on Mount Darwin a few days ago. This is getting a little worrisome -- it's not too surprising that we had a problem at Mount Darwin, since the target was in the air, but we sort of expected to see contact at Puenta Arenas.

It's remotely possible they're not working any more, which would be awful; the MB contact plate is our only way to reliably sense the soil, so that would take out our ability to IDD soil targets. However, the switches are redundant for this reason, and unless there's a pebble stuck behind the contact plate or something, everything is probably just fine. We'll have to do an experiment on this in the near future.

But not today. Today we're driving.

If you can call it that. We're going to spend most of the day just turning around -- a slow and painful endeavor on a vehicle with a broken wheel. We have to use the fact that the RF wheel is an anchor, by pushing and pulling the whole vehicle around it. It's not precise, and it's not pretty, but it's tested and it works.

And it's slow. Every turn segment -- a single maneuver gets us about 14 degrees or so -- needs a visodom update afterward, and that costs us around 3 minutes. Since we need to turn about 180 degrees, we need about 13 of these, more or less. We'll end up spending 40 minutes or so just turning, out of a total drive time of a little over an hour. Take away the overhead at the beginning and especially the end of every drive, and we'll be lucky if we make any progress at all.

But the right way to drive this vehicle, it seems to me, is to be optimistic. What happens if everything goes right? Well, we might possibly manage to haul ourselves another 3m or so toward where we actually want to go. So Khaled and I add in some commands that will take effect if we actually complete the turn, and we'll see how far she gets. As long as she gets mostly turned around, we'll be happy.

The poor girl. She's so much more agile than this, at least in my memory of her. She's like a dancer way past her prime -- arthritic and broken, but not reconciled to it. Not yet. Maybe never.


Spirit Sol 1101

Brenda Franklin is back and feisty again, and she's made us hundred-sol cookies. Chocolate chip, this time, in addition to the yummy ginger cookies she normally makes every time the last two digits are "00." Of course, we're not just planning sol 1100 today, we're also planning 1101 -- sol 13 in binary, as I point out.[1] ("I hope we don't have a sol-16 problem," John Wright quips.)

Yestersol's IDD placement didn't make contact with the MB, which has us a little worried. John looks carefully at it and points out that the target was floating above the mesh, which probably explains it. But this really sucks, since it means we've probably blown a science observation and might need to redo it. I send email to Ray and hope for the best.

Working with John, with no shadow, is such a pleasure.[2] It's rare these days that I get to work with one of the old-school RPs with no shadows around, and it's just so damn nice. We're both on the same page, and everything goes smoothly. Just like it oughta.

And you can tell those old days are getting pretty old. Today, Opportunity's drive will take her over the 10km mark! Spirit has 7km coming up, but Opportunity is probably going to continue to increase the gap from now on.[3] We'll see if the whole slow-and-steady thing works out.

But there's one thing we two old-school RPs fail to notice: we forget to enable the MB_2 contact switch before doing the MB placement. Kind of a rookie mistake, actually; and normally, fr_check catches this, but today it doesn't because of an unusual sequencing choice. (Which I later fix it to catch.) Happily, Rich Morris was paying attention in the IDD Flight School briefings I gave at the IST team meetings, because he catches this at the walkthrough.

Maybe he should start shadowing as an RP. I think we might need him.


[1] I make jokes in binary? Wow, I really am a geek!

[2] As you'll recall, John Wright and I were two of the original eight rover drivers -- and two of the four original Spirit drivers, at that. John is also one of my favorite people in this world, someone who makes me feel lucky to have the life I have. I'd never tell him that. :-) But it's true, all the same.

[3] Yep. Opportunity's now past 34km -- the second-most-traveled vehicle in the solar system, after Lunokhod 2. And we're going to break that Soviet record if it kills us.


Spirit Sol 1097

Ugh. I'm sorry, but getting here at 07:30 is just brutal. It puts me in a bad mood.

And I'm not the only one. Ray Arvidson is in a bad mood, too. He's often kinda grumpy, but today he's particularly grumpy, snapping at engineers and fellow scientists alike. When there's some hesitation at the SOWG meeting about picking a name for thisol's IDD targets, he half-snaps, half-whines, "Just pick a name, folks, so we can move on."

Later, I propose offline that we should use a new target namespace -- the names of different kinds of bugs. Ants, grasshoppers, crickets, etc. And the goal would be to guess which kind of bug crawled up Ray's butt today.[1]

For our relatively simple two-sol IDD work today, Khaled -- shadowing, and so in the seat as RP-1 -- decides to use one of the new R9.2 software features, AutoPlace. This lets the IDD FSW itself figure out how to put the IDD on a target, so we have to do less work. The mode Khaled's using it in is a kind of hybrid mode called "manual autoplace."

"Is that anything like jumbo shrimp?" I ask him. But not in a grumpy way.

[Next post: sol 1101, February 7.]


[1] I feel the need to be painfully clear about this, though: Ray is a great, great guy. On this particular day he was pretty grouchy and I wanted to make a joke about it -- maybe in part because I was pretty grouchy myself. But I can hold any one data point like that up to hundreds of others showing Ray in a terrific light. He's a great guy.


Opportunity Sol 1075 (Spirit Sol 1096)

As Steve Squyres points out, "We're falling victim to the extraordinary scenery we see before us -- flash is extremely tight." And he's looking to make cuts, and of course, one of the cuts we end up making is to reduce the quality of the ultimate and penultimate drive images, just after Ashitey made a (justified) stink about it. Oh, well.

So we're driving, but it's not a big drive, just a few meters, to get into position to do another piece of our long-baseline imaging. But because of all the tricky sequencing now required to leave useful tracks for VO in this terrain, it ends up being quite a lengthy and complicated sequence.

So much so, indeed, that Steve can't resist tweaking us about it at the walkthrough. "This has gotta be the highest sequences-to-meters-driven ratio ever," he says. "This sequence is a work of art -- this has gotta be the fanciest three-meter drive I've ever seen. This is what happens when you give the rover planners one and a half hours to go three meters."

"Back at the beginning of the mission," he continues, "we'd have done this with a single three-meter arc."

"But then your stereo baseline wouldn't be as good," Terry points out.

"And we'd have fallen over the cliff, yeah," Steve replies. "But apart from that ...."


Opportunity Sol 1074 (Spirit Sol 1094)

No driving is planned today. But yesterday's drive stopped a bit earlier than we'd hoped, after covering 2.19m of the planned 2.5m, due to increasing tilt. We knew the tilt limit was tight, but we allow only 8deg of tilt this close to the rim, and our limit of 7.8deg was about as high as we'll go.

But, looking at the data ... well, I'd be comfortable commanding another 30cm at a higher tilt if it came to that. Our slip wasn't increasing, which is what the tilt rules are really about, and if anything, we'd probably actually flatten out a bit more over that distance.

The possibility is alive for a while, until Larry Soderblom comes by. "Two point one nine meters is close enough," he announces, and that's that. No driving today.

I do have to come back later in the afternoon to give a demo for the college-aged son of a friend of Charles Elachi, the Lab's director. I don't know what's happened to college kids since I was in college myself. They seem to be opening the entrance gates to younger and younger students. Pretty soon, they'll be letting kindergarten kids in.

But he's a nice guy, and appropriately enthusiastic and impressed. So I won't hold his youth against him. He's clearly wise beyond his years.

[Next post: sol 1096 (Opportunity sol 1075), February 1.]


Opportunity Sol 1071 (Spirit Sol 1091)

I have good news and bad news. And good news. And bad news. And good news.

The good news is, we got satisfactory results from our VO test. Wiggle-and-scuff produced good results, so we're going to use that for our drives in this area for a while. (And indeed, it was used for yestesol's drive, which I wasn't on shift for. And it kept working.)

The bad news is, the drunken-sailor test didn't work.

But the good news is, that's due to a simple flight software bug in the command that tells the rover which arcs are allowed. And it's a bug that we can probably compensate for, so drunken-sailor isn't out of the running (or staggering) yet.

The bad news is, we can't take advantage of our success by driving thisol. We need to take PCAM images from this spot before we can move again -- they're needed for long-baseline stereo -- and we need NCAMs to target those PCAMs. And the NCAMs aren't down yet.

The good news is, the NCAMs eventually come down after all -- stuck in a pipe somewhere in the intarweb, or something. Whatever. We're driving!

Well, maybe it's a bit of a stretch to call it a drive. It's just a little 2.5m bump further along this cape. But the wheels are going to turn and they're going to take the vehicle with them; call it what you will.

The simplicity of the sequence leaves me time for chatting about an upcoming radio interview I'm doing. They've asked for the top five moments in the mission. "I've got Spirit's landing, Opportunity's landing, Spirit at the top of Husband Hill, Opportunity at Victoria ... and I'm taking suggestions for the last one," I announce.

There's no shortage of suggestions. Jake Matijevic proposes Opportunity at Endurance. "It was the first time we got to a really big crater," he says. "And it was both a scientific and an engineering accomplishment."

Ashitey has plenty of suggestions, too, and he disparages one of my choices. "Personally, I think getting to the top of Husband Hill was kind of an anti-climax," he says. "A lot of the drives we did to get there were more interesting."

"Fair enough," I counter. "But to me, getting to the top of Husband Hill wasn't the point; it's that it represents the stuff we had to do to get there." He looks half-convinced, so I press on. "It's like running a marathon. Crossing the finish line is great, but that doesn't happen without all the stuff that led up to it -- all the training, the 26 miles you had to run to get there ...." That does it. He's on board.

Julie Townsend plumps for the sol-18 anomaly. I wasn't going to include that one, mostly because I'm tired of it, but she makes a good case. "It had the whole team working together to solve a problem -- and actually, we had two rovers in crisis, with Opportunity on her way to landing right when that happened." Hmmm ... it's a good point. That one goes on the maybe list.

Then that leads us into the top five scariest moments of the mission. The sol-18 anomaly is one, of course; then there's catching a potato in Spirit's wheel, Purgatory, losing Spirit's right-front wheel with winter coming, ....

For me, one of the scariest moments of the mission is something Jake says during that discussion. I've heard it before, but not from him. "We're going to have to think about another hard decision," he says. "When to give up on Spirit."

Ashitey's response captures my feelings perfectly. "Never!" he exclaims. "We'll drive her on one wheel!"

But Jake points out that, well, budgets are being cut, and Spirit's limited mobility makes simply turning her off a possible choice.

Later in the day, John Callas (MER's project manager) stops by to see what's up, and Ashitey mentions that possibility to him.

"We're not going to sacrifice a vehicle," John says flatly. "That's not gonna happen."

And that's the best news I've had all day.

[Next post: sol 1094 (Opportunity sol 1074), January 30.]


Opportunity Sol 1066 (Spirit Sol 1087)

We're in what is probably the flattest, most featureless terrain this vehicle has been in, ever. You'd think that would be good news: no obstacles, nothing to hit. The problem is that we have this big honking hole in the ground called Victoria Crater, and we need to stay the heck away from it.

Our basic tools for making sure we stay away from something are visodom and autonav. Visodom helps you by telling you where you are, by comparing "before" and "after" pictures to figure out how far the rover actually went -- as compared to how far it thinks it went because of how many times it spun its wheels. The problem with that is that in featureless terrain, the "before" and "after" pictures look the same. We try to fix that by looking at our own tracks, but those have a nice repeating pattern -- a "picket fence effect" -- that can confuse the software. Looking into the crater at the nifty featureful stuff in there doesn't work either, mostly because it's too far away.

Autonav has its own problems in this terrain. With no features, it can't get good 3-D data about the world, so it treats that as a scary lack of data. Essentially, the flat featureless stuff gets treated like a cliff. And since there is a real cliff that we want it to be scared of, we wouldn't turn that off even if we could.

Normally, for historical reasons as much as anything else, Opportunity relies on visodom. Yesterday's drive stopped due to a VO failure caused in turn by the "picket fence effect" when we looked at our highly repetitive tracks. So what do we do to fix visodom's problems here? We have to make our own tracks more interesting.

So that's the plan. We pick a direction -- a direction more or less straight away from the crater -- and plan a test. Mark has a particular idea he wants to try for the first 5m, "but after that, it's up to you," he says. Gracious SOWG chair Larry Soderblom is on board with it; I don't even need to point out that spending a sol or two to do this checkout could save us a whole bunch of sols down the line.

So here's today's drive. We plan a 25m drive, broken into five segments, each of which tries a different test:

  1. Scuff with both front wheels on each step. As we drive backward, we periodically stop to rotate the right front wheel, then the left front wheel, away from us, in order to push up a chunk of dirt.

  2. Same as above, but we wiggle the left wheel instead of scuffing with it. This creates a different pattern on each side.

  3. "Drunken sailor" -- my favorite, of course, but not only for the name. This test tells the rover that it's not allowed to drive straight toward its goal; it must veer a bit to one side or the other. Since the real-world performance of the vehicle is never perfectly symmetric, this should create an interesting pattern out of little more than randomness. Plus, this version is the easiest to sequence.

  4. Every step, do a small turn in place.

  5. Finally, the "mother of all tests": run a step of test 1, a step of test 2, and so on down the line, until each has been done twice.

One of those oughta work. If they don't, we're screwed.

[Next post: sol 1091 (Opportunity sol 1071), January 27.]

Courtesy NASA/JPL-Caltech. Oh, my gods, is it ever flat here. Flat. Flat. Flat flat flat. Except, you know, for the giant scary hole in the ground. But otherwise, flat.


Spirit Sol 1085

Ah, brilliant. We've been working on releasing a new RSVP version to go with the new Linux version we're moving to. And they decided that today would be a good day to upgrade one of the RP workstations. (Not, say, yesterday, when there was no planning on Spirit and we would have had the whole day to work out any problems.)

And, of course, we're doing a whole lot of crap today. We're doing the first RAT daisy we've done for hundreds of sols, with the usual extensive MI followup.

Yay ....

It turns out right away that something about the new installation has major problems. Applications are crashing more or less randomly, including RSVP, sometimes within seconds of being launched. It looks like some kind of weird problem with the video driver, though why this didn't show up on our development machine is a mystery for now. But the bottom line is that the newly upgraded machine is useless for real work, and we have to switch to a backup. This isn't too bad, just irritating and time-consuming.

But we get through the day, as we always do. We discover late in the game -- fortunately not too late -- that due to a silly editing mistake, I'd screwed up the calls to some of our helper sequences. So I fix that before delivering, but I feel the need to go back and obsessively check everything before we can go on. "Sorry," I say, "it's just my OCD."

"That's OK," Cindy Oda says, "I like it better when the RPs have a little bit of OCD."

"In that respect, Scott's one of the best," says Ashley.

I get no respect around here.

[Next post: sol 1087 (Opportunity sol 1066), January 23.]


Spirit Sol 1082

"According to Brenda," Khaled tells me, "we're doing a tool change from MB to APXS, and that's it for the three sols."

Khaled and Brenda turn out to be right. You could say it's an easy sol.

But in our wonted way, we put the spare time to good use. At my request, Paolo has started to lay out an approach back to Tyrone, the spot where we bogged down on the way to McCool Hill. We won't be going into the scary soft stuff, but we're going to try to get close enough for the MTES to get good pictures of the unusually high-sulfur sand we churned up there. Then we'll turn around and head for Home Plate.

So we stand in front of this enormous printout of the winter panorama, and start drawing imaginary lines on it. Yeah, we could follow our old tracks here, but that would take us too close to these big rocks with a not-terribly-maneuverable rover. So we have to go this way, but we'll have to watch out so we don't anchor the wheel on this cluster of pebbles over here. We should drive to that mound, no farther, and halfway there we should assess whether to do a wide U-turn that intersects the mound or just go all the way and do a sharp turn once we're there.

That kind of thing.

Now here's a joke you really have to be on MER to get. "Hey, Rich," I say to Rich Morris. "You know how I told you you should write a song and call it the Rat Brush Jam?"

"Yeah," he laughs.

"Well, you should make up a dance to go with it, and call it the Solar Array Stomp."

The whole room cracks up.

"My joy is tainted only by my depression that I didn't think of that first," Rich says.

It would be a terrific day if it weren't for some bad news I get, confidentially, at the end. Sharon and I are talking about some rover-driving issues, and she tells me quietly something I need to know about the importance of getting things right on the Spirit drives.

"NASA HQ thinks Spirit is useless," she says bluntly. "They might shut her off in October. So it's that much more important that we have some visible successes."

Well, that's good to know.

But shut her off? Over my dead body.

[Next post: sol 1085, January 21.]


Spirit Sol 1079

I haven't worked with Khaled for a while. He's in fine form, still struggling a little but well on his way to being a full RP again. Today is all IDD work, and it should give him a decent workout.

The first sol's nothing: just pick the APXS up and put it down about 1cm away. It's the second sol that causes all the trouble.

We've got three IDD targets to choose from, spread across the face of the ridge that forms part of the Troll feature. Target 1, off to the right, is the science team's preferred target, and we can reach it pretty well, though we have to disable the wheel-volume collision checks to do it. Target 2, off to the left, is at the very limit of reachability, and is in fact unreachable by the APXS. Target 3, in the middle, is easy to reach but least interesting to the scientists. So we go with Target 1.

Only we discover, partway through sequencing, something we really should have noticed at the outset. There's a projecting knob of rock to the right of Target 1, so when we put the MB on that target, the APXS nearly collides with the knob. Bloody hell. Target 3, here we come.

With that under control, I go up to the Land of Opportunity to help resolve a question raised by one of the mission managers, Rich Morris. The planned Opportunity drive uses a waydisc that's mostly inside of Victoria -- in particular, the center of the waydisc, the waypoint, is inside Victoria. Now, the rover is aimed straight at the waydisc, and it'll stop when it reaches the waydisc's edge, which happens well before it enters Victoria. But theoretically, the rover's mobility code could decide to wander far off to the side, head into Victoria, and enter the waydisc from the side.

Now, we have various guards against that happening. They've already given the rover so-called keepout zones, which are like stringing up "Police Line -- Do Not Cross" tape around the terrain. If the rover crosses the line, it'll stop, and there's no way for it to get into Victoria without crossing one of these lines. In addition, there's a set of reactive checks, where the rover will look at its tilt and suspension and freak out if it appears to be going over a cliff. And, of course, there's our years of experience driving the vehicle, which tell us that it'll do the nominal thing.

But ... a while back, as a defensive measure, I wrote up "Rules of the Rim," which are similar to the "Rules of the Road" in which we documented our best practices for driving through the etched terrain. These rules are meant to document our best practices for driving around Victoria, and one of them says not to sequence drives such that the drive could nominally go into the crater. Rich's question is, does today's planned drive violate that rule?

It's a tough call. Realistically, the answer is no. But technically, we're violating both the letter and the spirit of the rule. And, grimly, because I know this means more work for the RPs on shift -- and, in the real world, pointless work -- I have to tell the truth. Yeah, it's against the rules. And moreover, it's against the rules for a good reason. We really shouldn't do this.

Happily, Paolo Bellutta, one of the RPs on shift, comes up with an elegant fix. There's a knob you can twiddle to tell the rover that it's only allowed to drive so far toward a waypoint. This means we can turn the normal, unbounded-distance command into a command whose nominal behavior constrains the rover to a circle around its starting point. By correctly choosing this setting, we can be that much more sure the rover won't enter the crater; it puts us within the letter and spirit of the rules, and it's a low-effort change. Paolo's brilliant, and everyone's happy.

So I'm back downstairs, back to my own rover. And just in time to hear John Callas point out something I hadn't noticed, and I used to keep fairly close track of this. Today we're doing a three-sol plan, for sols 1079 through 1081. Sol 1080 will be 12 times our prime mission of 90 sols.

Every month a year long, if you see what I mean. And we just keep going.

[Next post: sol 1082, January 18.]


Spirit Sol 1073

Well, let's see if we can handle this. We've got to do a tool change, swapping the APXS for the MB.

No, wait -- there's more. Before plunking down the MB, we need to swing the IDD off to one side so we can take a PCAM image. Oh, how will we ever finish in time?

Yeah. It's an easy day.

[Next post: sol 1079, January 15.]


Spirit Sol 1070

"Way to go, RPs!" Oded Aharonson exclaims over the telecon. "You guys are awesome!"

We can't believe it ourselves. There's Montalva, right in the middle of the IDD workspace. Spirit ended up less than 8mm from her goal position, and she kept trying to make it until the clock ran out.

Good girl. I love this rover. Way to kick off that fourth Earth year, baby!

So, since she made it, we're going to take full advantage of her new position: whip out the IDD and start working this outcrop over. We RAT-brush it, MI it, and plant the APXS.

[Next post: sol 1073, January 9.]

Courtesy NASA/JPL-Caltech. Way to start that fourth Earth year, girl. I love you.


Spirit Sol 1069

As of this sol, we're starting our fourth Earth year on Mars. For Spirit, at least; Opportunity's anniversary doesn't happen for another few weeks.

But we're celebrating it in a big way, with an aggressive drive to the Troll outcrop. Yestersol's IDD autoplace checkout got killed because it was taking too much time, but it looks like it was running OK. It just took it a little longer than expected to find targets, and when it got killed, the sequence was in the final cleanup phase anyway. So we're good to go.

But go where? The scientists would like us to go to the part of Troll nicknamed "Riquelme," but there's a slight problem with that. When you look carefully at our current position, it appears that Riquelme isn't just under the left solar panel, it's under the left middle wheel. That means we drove over it with at least that wheel, probably also with the left front wheel, and we'll drive over it even more getting away. When we do that, we contaminate the target with tracked-in dirt and also with small amounts of metal from the wheel itself, and in a case like this, that makes the target less attractive to the scientists.

So we're off to another part of the Troll outcrop, a section called Montalva. This is a low slab of exposed rock visible off to our left. As with any Spirit drive these days, this is going to be a challenge. We've got to back up while turning 100 degrees counterclockwise, then bump forward until Montalva is close enough to reach it with the arm.

Not only does this call for some fairly precise driving, it also means trying to climb a slope of maybe 12 to 14 degrees -- forward, yet, pushing one wheel. Not only that, but time is tight; if just one or two steps don't do everything they should, we'll probably fall short. It's about at the limit of what Spirit can do now, maybe over that limit, and we're careful to say so to the science team.

But I hope she makes it. That'll be a nice, quiet, but glorious way to start our fourth year here.

As another milestone, thisol we uplink r1000 -- the 1000th drive sequence sent to the vehicle. That's not the same as 1000 drives, because it's common for a single drive to use multiple sequences. But it's a cool moment to see those numbers wrap.


Spirit Sol 1068

Happy New Year, everybody! It's January 3, which means that tonight at 8:35PM Pacific Time is the 3-year anniversary of Spirit's landing.

We always take care in sequencing, but never more than when we have an anniversary like this one. You don't want the story of your three-year anniversary to be that you hurt the rover -- not that you'd want that any other day, of course.

So we're particularly careful about planning the drive to Troll. Troll is an outcrop just a few meters from our Winter Haven. Currently, it's under our left solar panel, but we think we can get there -- although, with the high tau we've been experiencing lately, we're concerned that the obvious approach to Troll leaves us with an unfavorable tilt.

At least we'll be able to gather lots of data about the drive -- Spirit's got only 10.3Mbits of data on the file system, perhaps an historic low!

Except that we won't be able to do the drive after all. Not today, anyway. It turns out tau is even higher than we thought, which means we have less energy to play with than we thought. So the drive will have to wait for another day.

Instead, we're going to repeat the third step of the IDD autoplace checkout -- just another capability added in R9.2 of the rover's FSW that aims to make us rover drivers damn near obsolete.[1]

While Chris Leger -- who wrote the code for that new capability -- works on that, Ashley and Terry and I go ahead and work on the drive anyway. So what if we can't send it up? That's no reason to deprive ourselves of the fun of planning it!

The drive to Troll will be challenging for our little five-wheeled bot. We'll face a decline in our northerly tilt, from about 7.5 degrees to about 5, and that can be a lot of change for a power-starved vehicle. Moreover, as we climb the outcrop, our westerly tilt increases, which means the solar-array wakeup would happen later in the day. Furthermore, we may simply be unable to climb the slope: it's about 12 degrees, and that seems to be around the limit of what we can do now.

But Jake Matijevic OKs the power issues, so our plan will be to do what we always do: try our damndest, and find a way to make it work if humans -- and plucky robots exploring other planets -- can.


[1] IDD autoplace enabled the rover to safely unstow the arm and place tools on targets that were outside the IDD's reach at the start of the drive. That is, you could drive to a target and use the IDD on it, all in one planning cycle. It was slow, but it worked. Just like us, the rovers got smarter as they got older -- but I'm pretty sure they didn't lose their glasses all the time. Damn glasses. Where did I put them?