(I moved this here from the "route-map" thread)



This would mean spending about one year (!) of the remaining rover lifetime for routine rock sampling alone...
But I still hope that the plan is to invest the bulk of the remaining life time in studies at Endeavour Crater, which is the main and highest priority scientific target, if I understood Steve S. correctly
The intermediate routine sampling stops will likely be significantly shorter in the future (1-2 weeks) with the potential for longer stops only in the case that we discover something entirely new along the way (BTW it is this latter possibility, that makes driving larger distances to new horizons so important IMHO

So I for myself rather take the last part of Steves quote:

How long is that again?

Yeah, actually I hope this is right, but given that Victoria's rim slopes down towards the south (as Phil illustrated beautifully a while ago), we may be able to see slightly into the interior of Victoria once we get far enough south/southeast. It may be a very prominent sight, especially when the capes are casting long shadows. It should be a very different view than what we had on approach to Victoria.

Don't forget that because radioisotope degradation, spectrometry readings that took a few hours years ago now take days... and days. I think this was a special case. Since Opportunity was going to be stopped for conjunction anyway, they decided to thoroughly analyze Santorini. I don't think this is going to be the case for most other stops along the way.

Remember, part of the Endeavour justification was that it was the right way to go anyway.....that only remains true if you do science along the way

Do the "sensing" devices have a shorter expected life span than the "imagers" ?
Or are they all in the How-long-will-your-toaster-work? category?

Of course It's not about the exact amount of time, which could be another 4 years or it could be over tomorrow ...

But the fact that it is limited and that it's expected value (in a probability theory sense) decreases with time, seems to warrant some prioritization of goals ...



That's True. With the unknown/small probability of reaching Endeavour in the first place it wouldn't make sense to do no stops at all until reaching the target. So I too interpret the "Endevaour Goal" as this kind of "imgainary" horizon that gives the direction (think "The journey is the reward." )

But nevertheless I would interpret the shift in strategy after Victoria to put more more priority to driving with less routine observations in order to open the opportunity for science studies of entirely new discoveries encountered along the way.

Maybe we are just a couple of kilometres away from the discovery of some completely new type of rock/terrain (something completely new as the blueberries were when we first encountered them)

The more aggressive driving opens the potential (no guarantee of course) for this kind of discoveries

This is certainly a problem for the Mössbauer spectrometer, where the half-life of its Cobalt 57 source is only 271.74 days, but for the Alpha Particle X-ray Spectrometer (APXS) the source is Curium 244, with a half-life of 18.1 years. I imagine the planners will not schedule much use of the Mössbauer (except at the next conjunction ) but the APXS shouldn't cause much of a problem.

Steve M

Is there something about the Mössbauer process that requires a radiation source with such a short life-span? Or will it be possible to build a unit with a longer useful life for the next mission that requires a Mössbauer spectrometer?

TTT

'Fraid so. To Mössbauer 57Fe, you need a Gamma-ray source emitted from 57Fe atoms decaying for resonance to occur, which basically restricts you to 57Co...

I believe the Mössbauer is used to discriminate among various Fe minerals. As such, it will be difficult to predict how often it might become an important analytical tool. Considering the significance of iron compounds in Meridiani Planum, on Mars, and wherever planetary science is being performed, it is an important tool use frequently in the xyz directions of any exploratory campaign.

Prior to these rover missions, how many people have ever heard of a Mössbauer spectrometer? Certainly not me. Probably only a few here have. I'd like to know the answers to TTT's questions, considering how amazingly useful this analytic tool has been to the MER missions.

It has been a long-stated goal by Steve Squires to examine cobbles after leaving Victoria Crater. The only question was which direction to head in while looking for them. They have now examined one cobble. How many more they will pass by and how closely they will look at them remains to be seen.

Some pictures from the new site are available here: http://nasa.exploratorium.edu/mars/opportu...cam/2009-01-19/.
There was a 115m+ drive during sol 1774 and I'm now working on the map. It should be posted soon.

Here's a reprojected partial panorama - makes it easier to see that crater off to the west.

Phil

Sol 1774:



Anaglyph:



Not sure what that is in front of us (south) - a crater? Speed bumps?