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.

Think we're going to be seeing a LOT of this cliff face in the days ahead...

Click to view attachment

Wrong cliff face, methinks. That's St Mary, not Verde. Unless I'm misinterpreting what you mean.

Brian

Sorry BrianL, should have been clearer... I know this isn't the bay she'll enter in, I meant that this looks like a good target for Oppy once she's down in the crater, cos of all the layering we can see.

Of course, this will be our first stopping point...

Click to view attachment

What impact is this going to have on the energy production due to excessive shading. Maybe we will go in a few metres parallel to the cliff and just "dash in" for a closer look once targets have been identified

There is a loss due to shading but it's less than you would think. At the moment 40-50% of the insolation is diffuse (and more if Tau is > 0.7) which is not affected by the shade so even if she parks right up against a wall she should not lose more than 20-25% of her potential power.

If she stands back a bit from a cliff so that it directly blocks, say, the rising sun for 3 hours past local dawn that would block approximately 10% of the daily total insolation. In addition there is a positive effect where a cliff that blocks direct morning sun will reflect evening sun so that effective insolation in the afternoon will rise slightly.

Since she is currently generating 800+whr/Sol she has plenty of power margin to do this sort of work right now.

It depends on what direction the cliff is facing, though. If we were parked right against a steep enough north facing cliff, we'd lose most of the direct sun and nearly half of the diffuse light, since the cliff would be in perpetual shadow now. Fortunately there are no directly north facing cliffs nearby!

The south-facing cliffs of Verde and St. Mary would be ideal for close visits now. I'd be interested in what being parked against a sunlit cliff does to local temperatures.

Still, we're not sure if they intend to inch up to cliffs or just sample the floor of Duck Bay. We've heard that they have a policy to avoid driving onto overhanging cliffs from above. Perhaps they'd be concerned as well about rockfall at the base, especially if they tried ratting the cliffface!

Bad idea... just imagine all the damage that could be caused by puddle water dripping onto Oppy's sensitive electronics...

I remember once reading that surface temperatures are far higher inside lunar craters than surrounding plains. I wonder if this holds true for Martian craters?

Yes, it generally is true. It's a matter of sunlight reflecting off the crater walls. If you look at THEMIS images from Mars Odyssey, you can see that craters tend to be warmer than the surrounding terrain, especially just after sunset.

-the other Doug

...Hmmm. Then the focus of any near-parabolic craters must be an interesting place to be, with regards to the generation of thermals.

Andy

Most craters aren't parabolic, and thus don't have perfect heat-focusing characteristics. But they do, indeed, heat the air above them and create thermals. If you don't believe me, look at the dust devil tracks in Gusev -- they very frequently spin out of craters.

You have to wonder why you see dust devils forming at Gusev and not spinning out of Victoria, here. I imagine there are a lot of factors, but still -- it is odd that some craters spawn dust devils and others don't. None of the craters at Meridiani seem to be spawning DDs, and yet lots of them are formed at Gusev.

-the other Doug

You do see DD's spinning off of craters but, from what I've read, they are more related to turbulance caused by air flowing over the crater. I've not heard anything about there being a heat differential over these crater causing the DD's.

Looking at wide angle orbital views, even at Gusev there are DDs only in a small region, which we happen to be sitting in the middle of. Why not elsewhere in Gusev? Is it the prevailing wind speeds? Is it that they do occur elsewhere, but the surface underneath the dust is lighter than it is here, so their tracks don't look dark? I seem to recall that we've discussed this before...

As far as crater shape goes, I would think even a somewhat not parabolic shape would still give a decent focus, if only the crater surface could reflect specularly, which unfortunately it can't.

1 p.m. EDT, Thursday, June 28

NASA will hold a media teleconference to discuss the scientific reasoning and risks related to the Mars rover Opportunity's planned descent into the massive "Victoria Crater."

Briefing participants are:
-- Alan Stern, NASA associate administrator, Science Mission Directorate, NASA Headquarters, Washington
-- Michael Meyer, lead Mars program scientist, Science Mission Directorate, NASA Headquarters, Washington
-- John Callas, Mars Exploration Rover project manager, NASA's Jet Propulsion Laboratory, Pasadena, Calif.
-- Steve Squyres, principal investigator, Mars Exploration Rover science instruments, Cornell University, Ithaca, N.Y.

Thanks for noting that, Doug. That's exciting news, but it is unfortunate that it was buried it in the NASA internet labyrinth. This is something that should be given more bandwidth. I'm putting it on my calendar.

Hi everyone
I couldn't find that NASA briefing I looked in nasa TV special events and it wasn't there.
The date is today isn't it.
Roy

Tomorrow. I think it will be an audio telecon with slides rather than a full NASA TV program.

It isn't on NASA TV schedule for tomorrow either. Might be audio only, like the final MGS teleconference.

Here is the press release. It's audio only.

Thanks Doug and Tesheiner
I really thought today was Thursday somedays I don't know what planet I'm on.

Audio is that like stone knives and bearskins
It's bookmarked and Ill try to get it for the ipod.

Roy

Looking forward to the teleconference today, which I'll have to listen to on my laptop cos my main PC's frakking soundcard has decided today would be a GREAT time to stop working...

I wonder what thoughts are going through the MER team's minds right now? Excitement? Reluctance? Apprehension? Fear? Impatience? (anyone want to tell us..?) I know Oppy herself isn't really alive (despite what I keep writing!), that she isn't self-aware, but I think that if she was she'd be thinking "Please, let me go in... I want to go in... This is what I was made for... this is what you built me to do, and sent me here to do... this is what I hauled myself out of Eagle Crater for, and trekked all this way south for... this is what I dragged myself through Purgatory Dune for, and dipped into Endurance Crater for... this is what I endured all those freezing martian nights and windy martian days for... this is why I Am, to go into this crater and study it from inside... rocks may fall on me, my wheels might get stuck in the dust, but down there is where I should be, where I need to be... "

At the end of the sol, if Oppy doesn't go in, what is she going to do? Keep scouting around the edge of the crater, looking down at one tantalising just-out-of-reach outcrop and bay after another? Send back countless thousands more images of all those layers and shelves and terraces that hint at wonderous geological stories, but are, too, just out of reach?

I think we all knew this day would come. The interior of VC is It. It's as far as Oppy can go. The rail tracks end here. There are no more targets within - realistic - driving distance.

I know many are worried that Going In might mean she never comes out again, that it's risking a valuable asset, but I think that's seen as acceptable and even necessary now. As much as we convince ourselves here sometimes, Oppy isn't immortal; the martian ghouls could claim her literally any moment, snuffing out her life with something as petty and frustrating as a snapped wire or a circuit failure, or as dramatic as a broken wheel or a lurching topple into a bank of soft dust. But it's time. She didn't come all this way, survive everything that's been thrown at her, to just meekly patter around the edge, like R2D2 trundling through that canyon on tatooine, beeping and tooting forlornly and plaintively, killing time, waiting for time to kill her. She came all this way to explore, to learn, and to teach us. Time to let her do that.

A major dust storm is brewing up on Mars as we've heard, a great billowing mass of red dust is broiling and churning away, getting larger by the second. It could end either of the rovers' missions if it pours over them, the dust choking and clogging them, cutting off their power, killing them as surely as a pillow smothering their faces. So what fate would we rather have for Oppy? To have her end her days rolling safely around Victoria, ticking off the sols, looking down on the geological Alladin's Cave that is VC's interior... or exploring the inside of the deepest hole we've yet reached on Mars? There's amazing science to be done in there... layers to study, dust spills to photograph in detail, rocks to gaze at close-up... cliff faces to peer up at from below, their boulders and ledges jabbing out of the rockface like gargoyles against the pink martian sky... imagine the images we're going to see from inside there...

Enough trundling. Enough peering down. Enough "that might be". Time to let her go and do what she was sent to do.

Go explore, Oppy. The stage is all yours...

What an inspiring speech Stu! You should write speeches for Michael Griffin. I'm sold...but I was never a hard sell in the first place.

O.K. Stu

You've pushed me over the edge. so to speak.
It's strange that trying to think about the pros and cons kept me hovering but, them gargoyles helped me decide to go for it.

Roy

The telecon should have already started, but the NASA news audio page still says "A link to the streaming audio will appear here before the event." and no link is there.

Here I go, spitting into the wind again. I think it would be great if Oppy couldn't go into VC - off we'd go on another cross-country adventure, hopefully southeast towards Big Crater, wondering day by day what is over the next hill and exactly what route we'll follow. New vistas, new adventures, that's what I'd like to see. A full-color 360 degree panorama from the peak of the western rim of Big Crater - that would be incredible.

But of course there is little double that Oppy is going into VC, and there will undoubtedly be interesting things to see there as well - I'm looking forward to MI close-ups of a vertical cliff. But I anticipate a lot of boring sitting around in one spot for ages, like Spirit has been doing lately.

The teleconference is still an hour and a bit away.

I must go back to school! Click to view attachment

1pm + 6h = 7pm and not 5pm.

I won't be able to listen to it after all. I see now that there is only a link to a RealAudio stream. Even if I would consider installing Realplayer on this machine, our corporate bit-nazis would not allow me to. Hopefully some nice people will post running comments here so those of us without access can learn of anything interesting being said.

The press release for the teleconference states that "[s]upporting images and graphics for the teleconference will be posted at: http://www.nasa.gov/rover," but I get "page not found" for that address. Perhaps the page goes live at the last moment?

TTT

Yes - it'll go live when the conf. starts.

They had sort of 'end of sad movie' music for the Dawn 'on hold' music. This is all a bit more up beat

Doug

Currently "You are the sunshine of my life.." - a little syrupy, but still, we do love those rovers.

http://www.nasa.gov/mission_pages/mer/070628/index.html

Sweet

Doug

Images and animations are here, now.
http://www.nasa.gov/mission_pages/mer/070628/index.html

Nice animation. Didn't think they would go that far really... If it's accurate

Hmm, that talk + the vids weren't really tailored to the discerning crowd at UMSF, I think...

I've been able to listen for a bit, here (though I was on the phone with my girlfriend for the first 10 minutes or so). What I got out of Squyres' discussion is that the *only* primary science goal that has been identified for the foray into the crater is the investigation of the "bright band" of evaporite visible in the crater walls. They *think* that this band is contiguous to the layering found in Endurance, and they want to look at compositions (particularly the leeching of certain salts at given depths) to try and both confirm that these layers were laid down at the same time as the layers in Endurance, and to determine if the same processes that leeched some salts at Endurance were also working here, several km away.

They're not saying that once the bright band is explored we'll up and leave VC. Just that this is the primary mission of the foray into the crater. Squyres made it sound like he's certain we'll see other things we want to check out once we get down into the thing.

Now we're hearing a litany of all the things that have broken on the rover since we left Endurance... and commentary on how we had to spend six months looking at the crater to decide that the best place to enter is where we started out...

-the other Doug

Specifics on entry -- they'll go to the southern end of the northern lobe of Duck Bay and do their initial toe-dip at that point, followed by entry. There is a ripple that follows the northern lobe, they want to cross it where it appears thinnest, at its southern tip.

-the other Doug

Edit -- toe-dip (which ought to define "entry") looks like it will happen on Saturday, July 7 or Monday, July 9.

Thanks for the summaries, O'Doug.

More updates -- Steve says that the biggest concern about entering Victoria is the greater danger of failure to the drive mechanisms (wheels, steering actuators, etc.) working on the steep slopes. He reminded us that when Oppy worked in Endurance, she was a much younger rover. He flat-out stated that if we lose a wheel inside the crater, when we *know* we'll just barely be able to get out with six good wheels, we'll never get out.

Alan Stern just commented on funding -- he sort of evaded the question by simply saying that the entry into and exploration of Victoria is, for the time being, covered by the currently approved mission extension. He wouldn't go into what might be decided for later extensions. And John Callas followed that up by saying what I've stated -- as long as the MERs remain mobile, every extension is a brand-new mission and would be sold to NASA HQ as such. Leaving unspoken but very strongly implied that an immobile rover would be harder to sell for an extended mission.

-the other Doug

Squyres: "The sole basis of our scientific rules of engagement entering the crater is rover safety. The next priority is finding a safe way to approach the bright band. We will not detour from the safest path for a lot of targets of opportunity, but if we see interesting things along the way, we may stop and do some science. But we won't deviate from our path to look at other interesting things." (Paraphrased.)

-the other Doug

Something that didn't go unspoken with the first Squyres Q'n'A I did

Doug

Not a problem, though I'll have to leave to go to work here in about 15 minutes. They're taking press questions now, so we're getting some repetition in information as people ask questions that have already been answered in the presentations.

This last question was a sort of muddled one about whether it would be easier and cheaper to cut down on communications with the rovers and just use auto-nav and auto-drive features of the updated software... Callas is emphasizing that we don't use DTE comm all that much, relay through Odyssey is a lot more energy-efficient.

-the other Doug

Squyres on targets outside of Victoria if/when they get out

1. Potato/Fist sized cobbles on the plains. Some have been meteorites, some crater ejecta, some have been 'wierd' - perhaps from distant craters or very deep inside victoria.
2. Follow up at Erebus - best evidence of water on the surface. Possibly Terra Nova as well or other deeply eroded craters.

Steve was just asked what goals they might have after finishing with Victoria.

He said there are two science investigations they want to execute out on the plains after we finish with Victoria -- the first is the cobbles we've been blowing by as we've been travelling. The ones we've looked at, some are meteorites, some are local bedrock, and some are just weird. They might be from a long ways away, or they might be from deep down and excavated by Victoria. We want to put together a story about rocks we could never drive to.

Second is following up on discoveries we made at Erebus (festoons and such). He's talking about going to similar ancient, eroded craters like Erebus, but not necessarily back to Erebus.

No mention of any kind of Big Crater/Ithaca.

OK -- I have to run, so that's it for summaries from me for now. I hope people have enjoyed them!

-the other Doug

p.s. -- thanks for taking up the task, Doug!

• Very confident of getting to the bright rocks.
• Another 'tens' of metres further in - fairly confident.
• Beyond that - all bets are off. We will not venture onto steep sandy slopes unless we know there is bedrock underneath.
• Not sure where this stuff lies compared to Burns cliff - need to do the science to match it up.
• Not going to attempt to get to bright band anywhere else other than Duck Bay. Wouldn't go close to Cape St Vinc. Cliffs are scarey things for little rovers.
• Regional dust storm - about a week old. Tracking it via MRO/MARCI with daily weather updates. It's regional extent - mainly south of Oppy. Don't have predicitive power for it - past experience suggests it may be starting to blow itself out.
• Dust storm blocks out sunlight, less power - but Opportunity is very clean. The storm is a risk- but well position to deal with it.
• Dust levels are the amoung the highest we've ever seen
• Mini-TES of bright band? Not really - from Mini TES it's all rich in sulphates. The differences in Sulphate chemistry we saw at Endurance were only evident in close detail. Primarily the APXS that pulls out the subtle differences. That + microscope. Rat+APXS+MI is what we need to unravel this problem.
• What would be the plan if the dust got worse for Oppportunity? We have experience with Spirit - we had a very dust rover, deep into winter, power levels dip to less than 300Whrs. Before the storm near Opportunity we were at nearly 800whrs, and off the showroom floor it was only around 900Whrs.
• Craig Covault : Anything you want to say about Spirit?
  • Steve mainly 'on' Opportunity but jealous of the Spirit stuff. 'Silica Valley'.
  • Identified another patch of bright soil but different from Gert.Wei, but right next to it.
  • Found rock with crazy nobbly texture ( difficult to IDD with ) - that's also high in Silica.
  • Tried to crunch some with the wheel - and nothing happened - but, right next to it, another piece of rock that did break. 'Innocent Bystander'
  • After studying that - time to get up onto Home Plate
• Total cost - ongoing cost?
  • To date from project inception to 4th extension - a little over $900m
  • Current annual rate is $20-24M
• Spirit hit by dust-devil?
  • No instruments on when cleaned (were using Mini-TES at the time)
  • Last few weeks - several cleaning events - two big ones - Spirit has more than Oppy
  • First jump at about 1320 local - possible direct hit from DD.
  • Imaged rover duck - pattern of removed dust very patchy. Some clean, some not - perhaps has something to do with DD.

And that's a wrap.

Doug

Interesting discussion by SS about the team's inability to distinguish, from a distance, between sandy slopes, which the rover cannot traverse if the slope is greater than 12 or so degrees, and rocky slopes with a thin layer of sand, which are almost as traversable as a rocky slope (good up to 32 degrees). In Endurance they didn't realize how good the traversability was until they got close views of the slopes.

TTT

I have been watching the press conference, but the images are up on the photojournal. This one in particular caught my eye:

http://photojournal.jpl.nasa.gov/catalog/PIA09692

When I first saw that, I thought "that has got to be enhanced". But no, the tracks really do stand out that well Very cool.

That was a lot of good information. They asked a lot of good questions, including most that I wanted asked. But one VERY major question was omitted. Nobody asked about the very recent changes in the rover tracks observed from So 1212, 1214, and 1216. These are clear and major changes that have not been observed before during any other time of the mission. The dark streaks appear to suggest the answer to the origin of the large dark streaks to the North of Victoria.

Back to the topic...So ingress will occur sometime around July 7th to the 9th. At least that is what is planned...after a few more tweaks and calibrations including the Rat tool.

look here

http://www.nasa.gov/mission_pages/mer/070628/index.html