I was about to go "4 months...well...it was only 3 really!" then remembered the fact that it looks like Sojourner did a little road trip of her own after we said goodbye

Doug

There is - it's called destacking and trying again after Phoenix has gone.

Doug

Bloody hell! The way the whole area beyond the middle-ground horizon is softened makes me think we're seing one of the DD's that deteriorates into just a swirling body of dust heading across the foot of El Dorado. Well spotted.

Doug

Same rule applies - you pay the travel expenses and I'll be there Kembal, Kentucky, I'm not bothered.

It was a lot of fun - I first gave that talk at Christmas for the BAA, but I re-'wrote' it with Keynote on my MacBook last weekend, and added a few videos to jazz it up a bit. Stu's got a great crowd of enthusiasts up in Kendal, and I have to admit I've never seen someone give the mandatory sky-notes type prequel to the guest speaker with such enthusiasm. A good crowd makes a good talk, so much kudos for Stu for assembling one and putting me infront of it

Doing it all again in York on Friday - http://www.yorkastro.co.uk/

Doug

We're at a low of 400whrs (175 more than Spirit at its worst), with the atmospheric opacity improving. Reports of death are premature.

But - any sol could be the end of Opportunity to be honest. I don't think this dust storm makes it any more or less likely.

Doug

This rather flies in the face of what Alan said on the Vic-Crater Teleconf a few days ago, saying that he was specifically looking to get more of out existing spacecraft.

Doug

Stu has photographic evidence

It's a case of 'see how we go'. The white band is the only target so far - they have no specific goals beyond that simply because they can't really tell what the terrain is like after that until they get closer to it.

It's probable that there may be a few tens of metres further exposed rock that is easily navigable beyond the white layer. However, if beyond that it's just sand, then they're not going to try 12 degree sand slopes, they're a death trap (see the trouble they had near Wopmay rock in Endurance - many sols of churning and wheels up to the hubs and beyond in sand)

It all depends on what the terrain offers when we get closer. If it's just a tiny bit of sand on top of solid rock, it's doable...otherwise it'll be a case of going as far down as they can, and then coming back out again.

Doug

The APL's main site works - but the near.jhuapl.edu site doesn't work either

Doug

Oh - I heard other names got used once or twice given the months of 50,60,70+ hour weeks involved.

Screw it - go for 2 pixels / degree 230 pixels for cash.

Doug

What would the diameter be for the middle of the disc to be 1 degree of latitude / pixel. That might be an appropriate figure to work from. My brain can't do the trig to figure it out

Doug

Sweet stuff

The dust probably wouldn't come off if you tilted the panels - it's fairly clingy. The motors only work one way ( I think) - I think they lock in place on deployment. And of course, what do you do if you end up with an array stuck up at an angle.

Doug

Slope too steep there perhaps - too close to the cliff edge w.r.t. shadowing solar and comms.

Doug

Just 'left' of it, if that makes any sense.

I'd say so, yeah. You drop not only 18% of your traction, but add a whole lot of drag even on rock. Slightly moot point given that there isn't a lot of exposed rock without sand involved near Spirit.

On the other side of the planet they've said that if they go into Victoria, then have a wheel fail while inside, it would be very hard to get out again.

My intepretation is this

Well - with a stuck wheel they can't really climb onto the sorts of slopes that would be much better than Low Ridge haven. 20-25 degrees would have been better I would have thought - but the rover just can't get to that sort of terrain any more.

Doug

They didnt want to do a rush job last time - remember they were trying to get to McCool hill which would have been amazing - but the stuck wheel, and then the Tyrone sand trap...things went against the rover so they had to get somewhere, fast.

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

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.

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

Doug

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

Sweet

Doug

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