Planning for Winter – a(nother) chat with Scott

As Oppy continues to head north, scouting for suitable places to spend the imminent winter, a lot of us are wondering just what the plans are for the forseeable future, and where she might end up. Who better to ask than rover driver Scott Maxwell, a great friend of this blog… So, sit back and enjoy Road to Endeavour’s latest fireside chat with the always-amazing and generous-with-his-time, Scott…

Q: So, here we are then – Cape York! Was it worth the wait? Is it all you hoped for as you drove Oppy away from the cliffs of Victoria and steered her across the great Meridiani desert?
A: Endeavour is taking some getting used to.  With Victoria (and
Endurance), you could readily get the scale of the thing — you could
easily see all the way across Victoria, for instance, as big as it
seemed at the time, and at least it seemed like you could understand
how big it was.  (Having been to Arizona’s Meteor Crater, which is
only about twice Victoria’s size, I know those appearances can be
misleading, but still.)

Endeavour is a different beast altogether.  I still don’t feel like
I’ve fully grasped its scale.  It will take a while to internalize.
Fortunately, we’ll *be* here for a while, so I’ve got time.  🙂

Q: Can you describe how you and the rest of the team felt on that fantastic August day when Oppy finally rolled up to Cape York and made landfall at Spirit Point?

A: Back in the early days of MER, I coined a portmanteau that I think
captures these feelings quite exactly: exhilarausted.  It was quite a
long hard slog across the plains; frequently, you’d come in and do
almost exactly the same thing that had been done the day before.  I
tried to keep it engaging by coming up with new stuff, but there’s
only so much you can do — at some level, it’s just three years of
plodding along.

To actually have that pay off at last was wonderful, but I won’t
pretend we weren’t all a little worn out, too.  Ready for a change of
pace, you might say!

Q: In the sols that followed it must have been exciting to see Odyssey
Crater open up ahead of you? I know we stopped at a few craters along the way from Victoria, and Santa Maria was especially impressive, but those huge blocks of ejecta scattered around Odyssey looked pretty special…

A: I don’t know if you’ve noticed, but there’s a very slightly larger
hole in the ground near Odyssey.  *That’s* the one I *really* want to
go into …. 🙂

But yes, Odyssey was a nice one, too.  At this point, as Bill Murray
said in “Groundhog Day”: “Anything different is good.”

Q: And are you all enjoying the view across the crater? Those high hills on the opposite side of Endeavour are stunning, aren’t they?

A: Yes, although as I said above, it’ll take me a while to get used to
the view, to really internalize it.

What I really need to do is go to Manhattan (which is about the size
of Endeavour), walk around it for a while to get a sense of how big it
is, and then go up in a skyscraper to see the thing from a height.  I
intend to do that in my copious free time.

Q: Tearing ourselves away from the beautiful scenery, can you give us a quick “health update” on Oppy? What kind of shape is she in as she explores Cape York and prepares to hunker down for (yet) another martian winter?

A: Nothing has recently gone wrong.  We’ve had a stuck right-front
steering motor for nearly seven years, and an arm that won’t wave left and right for, I guess, about four years.  We’ve had to baby the
right-front drive motor since soon after leaving Victoria, so about
three years.  We haven’t had any luck resurrecting the Mini-TES
instrument, though I don’t know whether it’s been formally declared
dead.  And the Moessbauer spectrometer has significantly degraded
(damned radioactive half-lives), though it still works.

On the other hand, there’s a lot *right* with Opportunity: she can
move well, she can use her robotic arm, and her drill still works, as
does her APXS spectrometer and her microscope.  All of her cameras,
including her color-capable cameras, are in fine shape.  And her
antennae, heaters, solar panels, and so on are all working well.

If we landed Opportunity today, we’d still be perfectly capable of
doing her primary mission.  Not bad for a rover that’s almost eight
years into a 90-day design lifetime!

Q: Over the past week or so it’s become clear that, after all the build-up, the search for those “Holy Grail” phyllosilicates has been put on
the back burner, and the new priority is to find a north-facing slope where Oppy can park up for winter. Are you really that worried that Oppy might be in danger if she can’t find a suitable winter nest soon? When do you need to have Oppy parked safely by?

A: The date is a little flexible, but we’re going to try to reach a
Winter Haven area by the time MSL launches.  MSL has the option of
stealing most if not all of our communication passes for about a month
following its late-November launch, and it’s soon after that — in
early January — that we would desperately need to reach our winter
location.  So a conservative plan gets us where we need to be by late
November.

It’s a little annoying, because we probably won’t *really* need to
worry about it for another month or so after that.  But this is the
right conservative plan — application of the kind of thinking that’s
kept us alive this long — so I’m in favor of it.

One piece of good news is that our chosen Winter Haven location is not far from the phyllosilicates, so we’ll have only a few hundred meters to drive when winter is safely behind us — and, of course, the
phyllosilicates have been there for a few billion years now and aren’t
going anywhere in the next few months.

Q: There appear to be concerns about power levels on Opportunity for the first time (besides the major dust storm several years ago). Why now?

A: As you know, we depend on cleaning events — when the wind comes along and blows the dust off the solar panels.  As it happens, we haven’t had any good cleaning events for a while (we’ve been mostly out on the plains, where they’re more rare), so Opportunity’s solar panels are dustier than usual this year.  Combined with that, the atmosphere has a little more dust in it than usual.  Those factors combine to reduce the energy coming out of the solar panels.

If we got a good, strong, well-timed gust of wind, this could all
change tomorrow!  But since we don’t control the wind, we naturally
have to assume that won’t happen.

Q: With winter fast approaching, obviously the performance of the solar panels is going to be crucial. How is the efficiency of Oppy’s solar panels compared to when they were new (apart from the dust)?

A: The solar panels themselves are doing fine.  If we could manage to get the dust off of them, they’d be practically as good as new!

Q: I think many people have been surprised and delighted by how quickly Oppy has driven up Cape York, and we’re now really looking forward to seeing the landscape features up ahead, which look a lot more interesting, on HiRISE images, than the features at CY’s southern end. But she did seem to scoot very quickly past the spot where those phyllosilicates had been detected from orbit. Was that just because you know you can come back and look for those properly after winter, or because there was no obvious sign of them that made you *want* to stop?

A: Nope, we haven’t had a good enough look to assess it, and we don’t
expect to do so until post-winter.  Right now, winter is driving (so
to speak) all of our mobility decisions.

Q: So we’re heading north, at quite a pace, too. What’s the plan now? How *far* north are you going to go? Are we going to go as far as that v-shaped ‘cleft’ cut into the north edge of CY? Have you identified a single specific site where you want to park Oppy for the winter, or is there an area Up North where Oppy can still trundle about, that would allow her enough sunlight to keep doing science?

A: The region we’re heading for is around C6 in your map.  Our hope is to find a fairly large region where we can not only survive but continue to move around.  Around C6, orbital data suggests we could see north-facing slopes of 15 degrees or even better, which is what we need to do science while we wait out the winter.  Our needs for pure survival are more modest (somewhere between 0 and 5 degrees of northerly tilt, if I recall correctly), but of course we’re greedy.

In the worst case, we’ll find a spot where we can simply survive, and
we’ll sit still and do the radio science experiment that we had hoped
to do with Spirit, measuring the interior of Mars from a point on its
surface.  Far less interesting for me, but still cool science!

Q: …and after Cape York? I know the plan is to drive across Botany Bay and visit Sutherland Point, but be honest, aren’t you just itching to send Oppy up those slopes to the south and go scouting for phyllosilicates up on Tribulation? Is it even possible that Oppy could make such a climb, after  all this time and after all she’s been through?

A: *I* want to do that — for many reasons, including that driving to
Tribulation gets us that much closer to breaking Lunakhod 2’s
extraterrestrial drive-distance record — but the science team is
focused on the putative phyllosilicates to the east of Cape York right
now.

As for whether Opportunity can make the climb … well, you know what I always say, Stu: never bet against the rovers.

Q: Finally… Curiosity’s launch is fast approaching. Is there much friendly rivalry between the MER and MSL teams, especially over this fascinating hunt for clays? Do you know yet if you’re going to be involved in that mission?

A: As far as I know, MSL hasn’t announced its driving team yet, so you’ll know about that more or less when I do.  From a purely scientific perspective, the rovers’ results would complement each other — finding clays in one spot is nice, but finding them in two spots lets you say a whole lot more about global processes.

From a non-scientific perspective … yes, there’s definitely a
rivalry, and my baby Opportunity is going to win.  🙂

Thanks Scott!

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