An underlying problem is that Mini-TES on both vehicles does a huge ammount of work both looking at rocks and soils - and doing atmospherics and we never really hear much about it.

The radioactive sample in the Mossbauer spectrometers is now less than 1/8th of the strength it was at launch - so it takes not 12 hours, but 4 full days to do a good Mossbauer spectrum with either vehicle - thus they do them less often - only when it's really really worth it. The same is not true of the APXS though - that's fine.

The IDD's are conisdered a 'consumable' - particularly given that from time to time they will issue a command to take an image with the Opportunity MI and it wont work. Onboard software automatically trys again and to date, it's never failed on that second command - but it's a symptom indiciative of wear and tear within the ribbon like cables that run down the arm to the instruments.

Also - as anyone who got bored of the Olympia outcrops west of Erebus will tell you - on of Opportunity's shoulder motors is unwell - one winding is broken and thus it can quite easyily stall, particularly when reaching out left. It's one failure from being unuseable. Opportunity also has a failed FR steering actuator.

Spirit - it's RAT is worn out and can only do brushings, not grindings. It's FR drive motor is gone and that wheel is now locked so it plays the role of soil-plough as they drive. This also limits the slopes it could navigate from 30ish degrees with 6 good wheels, to less than 10.

From a 'doing science' perspective - here's the current rough 101...

Spirit - just about finished in the Low Ridge Haven area - it did all the IDD work on the local soils one could possibly imagine - and has since shuffled between a few local rocks/outcrops - a partial visit back toward the Tyrone area of white soil dug up by the wheels sone time ago. Now it's a case of driving back toward Home plate - perhaps via one or two other targets. Power is still fairly low (<400 Whrs ) but on the up.

Opportunity is in sprint-pancam-sprint-pancam mode as it goes from cape to cape around the rim of Victoria crater. There is little point in IDD work on any of the rocks up on the annulus as they are no in context - the power, time and downlink needs to be spent mapping out the stratigraphy from outcrop to outcrop around the rim of the crater until they've done a fairly significant navigation around the thing - more than 120 degrees, probably not as much as 240 degrees.

Doug