"Hey folks! I’m on-duty with Opportunity this week and it’s going to be pretty exciting. We are in the process of driving the rover over to the wall of Cape Verde to study the layers of rocks there in much greater detail. I will be posting updates all week with the spectacular new pictures that we should be receiving. Stay tuned, it’s going to be a pretty cool week!"

Thanks for the update Ryan : http://martianchronicles.wordpress.com/200...ng-to-the-cape/

I wonder how close they'll get. I think no closer than the height projected from it's base ( i.e. 45 degrees )

Rock on!!!

Woohoo!! Go get 'em Oppy! About time our gal lifted her eyes off the ground and looked up again.

The view in the drive direction on Sol 1484.

Taken with the R2 Pancam.

jvandriel

Click to view attachment

• Because of the Sun's rays : Mmm... The wall is on the North side. Now Mars is heading close to the solicite, hence Mars' tilt is close to 23.5 and the Sun will rise on the South-East toward to South-West side and I seems that there will not have any shade close to the wall of Cape Verde in all day. (I am not very sure on this, I invite someone to correct me on that part).
• Risk of any some loose material from wall? In spite of the fact there has winds, the rock and terrain are already firm except if there will be some Marsquake.
• Sandy surface due to the deposits from the wall of Cape Verde. Yes, I see some deposits close to the wall but I am not able to precise about its measurements.

Why do you think that Opportunity won't be closer than the distance of the height of wall?

Restricted visibility for Mars Odyssey communications. You would probably be taking a 1/3rd off total downlink if you brought the local horizon to 45 deg elevation (given that the spacecraft will appear to move slower nearer the horizon, thus more of the session, and thus the data, is sent at the lower elevations. )

Doug

I'm probably missing something very simple here, but how long does it take to take a photo? Why can't they do short in-out maneuvers for the close-up snaps, backing out each time to a better location for sunbathing and data transmission?

The problem would be if something unexpected happened that aborted the drive-away, anything from wheel slippage to a 'safe mode' event. That could potentially strand Oppy in a very bad place and the situation could deteriorate rapidly if there wasn't enough sunlight or ability to 'see' the orbiters.

When I sew the title of this new topic (I din't notice it was in Oppy section) I thought : I do not remember of any launch scheduled at Cape ...Canaveral !
After last week news of nearly shutting the rovers down...it's even a much better new !

A finite risk, certainly, but maybe manageable. I guess you'd have to do repeated stabs to and fro along the same track going a little further in each time, with the back-outs at the far end being slightly downhill (which they probably would be anyway). I doubt if the total daily insolation anywhere (in fine weather) would be as bad as it was out on the plain during the dust storm, and if you're just edging cautiously out of trouble as opposed to sending lots of data you don't need that much relay time.

If it's the only way to address a major science objective some risk is maybe worthwhile?

Thanks, Ryan, for the heads-up on this week's plans.

With regard to how closely Opportunity might approach the cliffs of Cape Verde, I think the local geomorphology also limits the places where Oppy is likely to tread. I would guess that the toe of the talus slope surrounding Cape Verde is a boundary beyond which this rover is unlikely to stray.

"We're hoping to get close enough to reach out and touch the face of this cliff,"

Squyres, in the TPS Rover update for March.



Mr conservative here got it wrong.

Great news IMO!
(I was planning to post the exact same piece of info. Doug, you beat me.)

"Opportunity roved the first 5.5 meters (18 feet) of the journey to Cape Verde on Sol 1484 (last Thursday, March 27, 2008) and followed that with another 5 meter (16.4-foot) drive on Sol 1486 Saturday (March 29, 2008)"

Next drive is planned for sol 1489. Images should be down in less then 24h.

So, this is the "surprise" SS talked about a few weeks ago! I like it

I like it too! And can't believe the "reach out and touch" line. At first I thought: "April fools?"

Based on the blog report, here's my estimate of the target location (enhanced and cropped from a pan posted by CosmicRocker):
Click to view attachment
I can understand the drooling going on contemplating that layering!

There is a quote from Steve Squyres in the latest MER update on planetary.org which relates to this:

"'We're hoping to get close enough to reach out and touch the face of this cliff,' Squyres said Friday. There are a number of things that make that 'kind of scary,' he said. 'One is that there is a very steep and rocky slope right below the cliff and those are always difficult to maneuver on.'"
======
Stephen

Edit: I might add there one or two other tidbits about the Cape Verde adventure in that planetary.org page people might want to check out.

Well... after the number of times I have suggested that Squyres and company might well decide to trundle over to the rock face at Verde, and the equal number of times I've been told that it'll *never* happen, I feel good about the plans right now...

-the other Doug

"Here's an obvious scenario that better minds can critique: we will descend hugging the clockwise cliff but also at some safe distance from it (lest a rock should become dislodged during the next wind event or daily thermal cycle and fall on the solar panels), occasionally turning to face it (but still at some safe distance) and using the full reach of the instrument arm to RAT and take micrographs and readings." This from my post of June 24, 2007 starting "The Descent into Victoria" thread, before the sandstorm etc. intervened. As noted, an obvious scenario -- you just have to have a little patience!

That would be my choice, too. It appears to be the part of the layered cliff face that can be approached to within an IDD-distance, while avoiding most of the talus and wind-blown sediment. It also is a place where daily sunshine and satellite communications should be minimally affected.

I liked this SS quotation..."For now, all eyes at Meridiani are on the base of Cape Verde. The stereo images the rover took of this "promontory" from the rim last year show striking layers within the bedrock. "The Pancam image we're going to take once we get into position at the base is going to be just stunning, like nothing you've ever seen," Squyres promised.

I can hardly wait.

The view in the drive direction on Sol 1486.

Taken with the R0 Navcam.

jvandriel

Click to view attachment

Testing the surface, I suppose:
http://qt.exploratorium.edu/mars/opportuni...76P1212L0M1.JPG

That looks a bit too loose for my liking.

Phil

EDITED - I received some feedback which said... "We are aiming for the triangular piece of layered bedrock that is just to the right of Oppy in your picture. Given the shadows we have seen on images taken on Sol 1489 we might not be able to get so close, but we will try."

OK, Opportunity getting to the base of Cape Verde is just too tempting an image to not start looking at producing an artist's view.
Here's my first second attempt - feel free to chip in with any thoughts (and yes, there are tracks there [which I've also revised, plus a few 'turns in place' tracks]).
Click to view attachment
Revised image based on the advice above.

This will form part of a wider panorama that I am still working on, but the file will be about 25mb when I'm finished.
Here's a small preview.
Click to view attachment

Enjoy
Astro0

Astro0, Old Matey, Why don't you make a movie 'short' of Oppy puttering around Duck Bay, with the clouds rolling by and a suitable sound track?

On a more serious note, I wonder if someone could do a precise calculation of Oppy's daily solar energy intake in that near-wall position. I fear the result would be disconcerting!

Yes, the approach looks a little dicey! (How's that for Brit speak?!?)

We're well past the equinox now, heading towards northern summer. That means that for Oppy, near the equator, the sun has to be on the northern half of the sky all day. It would rise in the ENE, climb up high in the north, and set in the WNW. Definitely not optimal.

Power is one issue, but I wonder what the imaging will be like for shadowed targets. I would think longer than usual exposures would work well. I can't recall any closeup imaging of large shadowed regions from either rover before.

Oh, hold on - you're right. An equatorial site, during northern summer, will have the sun in the north at noon. At high summer, it would be 25 degrees from zenith. Thus - at noon, mid summers day, a 10m cliff would cast a shadow of about 4.6 metres.

So shadowing WILL be an issue (as indeed, the 4pm navcam image taken a few sols ago shows)

I've got it right this time havn't I? Equatorial sites would have the sun at zenith during northern spring and autumn, and then experience two winters as it were, at northern summer (when a site 25 deg north of the equator has the sun at zenith) and northern winter ( when a site 25 deg south of the equator has the sun at senith)

Doug

That's right, two very mild winters.

Does anyone know the current subsolar latitude on Mars? Equinox was Dec 10th, solstice is June 25th, so we're past halfway to solstice, but the sun moves northwards much more quickly near equinox, so I'd guess that the sun at noon is currently between 15 and 20 degrees to the north of zenith for Oppy.

The current subsolar latitude is roughly 20 deg north (this is from Mars24).
Edit: And the current solar elevation for Opportuity is 67.7 degrees.

--Emily

Sunrise\sunset (on the plains) is at around 5:55AM local mars time at the moment and on a typical Sol the percentages of the the total amount of power generated per hour of each sol is [very roughly]:

12-1PM:15%
1-2PM:13%
2-3PM:11%
3-4PM:7%
4-5PM:3%
5-6PM:1%
(similar numbers apply in reverse to the morning)

My take would be that they could risk being in the shade of the cape for quite a few hours in the evening without it being too risky in terms of overall power loss, being in shade from 3PM would only lose 10-11% of total daily power. It might have a significant impact on thermal management though which is something to bear in mind.

Presumably Oppy would be in full shadow all morning, until some time around local noon. Do we have an estimated power input during this shadowed period? Then how many hours of direct sunlight would follow before shadow re-covered it? Can we estimate the southerly tilt of the solar arrays in the near-wall position?

You all love calculations. I love pictures :
Let them take pictures of the place they want to go at different hours of the day.
Would be nice, eh ?

A start has been made, courtesy of HHAW, for your edification, Climb: Shadow animation
However, we need watt-hour numbers to judge the hazard of a given location.

That's some drive ahead of Oppy.
Click to view attachment

Anyone want to pick the route?

Astro0

left 40
go 10
right 90
go 5
end

MER works like a LOGO turtle right?



Doug

Judging by Horton's animation it seems that the Oppy's Solar panel deck is effectively already in shadow by 4:30-5:00PM local time. That makes sense as it is at around a 15 degree incline facing away from the setting sun which would correspond to about an hour or so of sunlight.

The shaded zone at Midday seems to be pretty close to the wall so I think that they can probably manoeuvre fairly close in and keep the rover in direct sunlight until ~3:00PM without too much trouble. That would keep the power impact below about a 5-7% reduction from the levels it currently achieves.

Here's a revised version (third) of Oppy at Cape Verde based on some advice and a target.
The path is just my artist's thoughts, not actual. The position of the rover could be in a variety of orientations.
Not science, just art
Click to view attachment

Here's the revised panorama as a thumbnail. Large version will come once Oppy arrives at the Cape.
Click to view attachment

Enjoy
Astro0

Based on the above...here's where we could be headed.
Some fantastic layering for Oppy's eyes and ours to bug out on.
Click to view attachment

Cool

Astro0

If Oppy can actually get that close to the Cape safely, then it should be the highlight of the entire mission at Meridiani.

BTW, I would also like to see the rover traverse lower to inspect the deepest layers. I don't know whether that's possible because of the results of that test drive over the dust layer the other day. It looks like Oppy could safely get down to the lower levels, but I don't think it could make it back up the slope along that dust layer. Perhaps it could if it traverse in a Zig-Zag shaped route. I don't know. I hope the MER team finds a way to do it.

Yeah, I have the same concerns...that deep. loose soil is scary to the nth.

Good thought on the zigzags, though. I'm assuming that the development team at some point determined sideslip coefficients? Would be interesting to know what the limits might be as a function of tilt angle, but they're probably predicated on a more rigid surface...

I have not heard *anything* regarding the terrain handling ability of MSL vs MER's. Maximum slope up/down, maximum slope along-slope, soft-sand/dust, etc.

Of course, MSL should be able to handle dust that would be up to or over MER's hubcaps... it's hubcaps are higher!... but what's it's ability in proportionately deeper dust/sand?

Future missions will more and more need greater terrain handling capabilities beyond the baseline level of MSL and MER. Even if a wheel fails, as on Sprit, it should be possible to convert it to a free-wheeling mode, and not terribly cripple the rover on slopes or in soft terrain.

Going to have to tip-toe through this lot... should be some gorgeous pictures in the days and weeks ahead tho!

Click to view attachment

Click to view attachment

I'm of the same opinion.
But if you have a look to today's lot of hazcam images, my felling is that the rover drivers don't share our same concerns. Opportunity drove straight down the slope over the scuff.

Here's tosol's (1491) navcam mosaic.
Click to view attachment

You hav to admit, cape verde is a compelling target. I would be interested to see the layers up close. Particularly those filled fractures. BTW any news on the status of the mini-tes on Oppy?

This is just the start of the sol 1487 pan but as it shows the region we're all interested in I thought I'd process what is down so far.



Click image

James

Great blog, great pan! Looks like you'll have a lot of work in the coming days...

Oh boy we're gonna see some sights over the next few days and weeks... here's the latest view...

Click to view attachment

..."...as it shows the region we're all interested in I thought I'd process what is down so far."

I've kept looking at the transition between the cobbly/blocky surface next to the base of the cape and the flatter, but dustier, more mantled surface further from the cape... and keep thinking that slope angle limits permitting...... there's a potentially drivable route...

pant-pant!

On the full resolution image we can clearly see the "pavment" under the dust so, I think it'll be driveable.

Couple more pieces of the puzzle filled in...

Click to view attachment

I know others will do a lot better - by getting rid of those horrible dark lines, for example - but I wanted to have a go... can't resist this low angle lighting...

And a quick 3D of the base of the cliff... looks like there is some interesting terrain over there, some dips and hollows, and some very interesting rocks to look at close-up...

Click to view attachment