Uh, oh, now the filter wheel is acting up
http://qt.exploratorium.edu/mars/opportuni...KCP2425L7M1.JPG

Well, it's like the 'other Emily L' (Litella) used to say, "it's always something..."

Looks like a wonky L247 sequence, with a real long interval (404 seconds) between the L4 and L7.

Evidently the filter wheel didn't index properly; I'd suspect that they use an encoder to know which filter is where.

We'll check Weekend Update...

--Bill

Opportunity looks to be having some trouble with her left eye filter wheel.

Opportunity woke up and started imaging very early on this particular sol, at around 8:18 in the morning. This is the earliest Opportunity has woken up and taken images since way back on sol 455. From the looks of the images, Oppy was none too happy about getting up this early (maybe she hadn't had her coffee yet).

The first left eye image of the morning, an L8 sun finder, came back as 1 pixel. I'm not sure what this indicates. This could be that the filters weren't set right and the auto finder failed or it could be something else entirely.

The next 3 left eye images appear to not have their filters perfectly centered and the offset from center appears to shift between images as if the filter wheel wasn't turning as much as intended.

The following 3 are very badly offset, and that offset drifts between frames as if the frame wheel still wasn't turning as much as necessary. As Bill noted, there is an unusually long delay between these images. Normally, there is only 20 seconds between an L2 and an L4, and as much as 35 seconds between an L4 and L7. This second set of 3 has almost 2 minutes between the L2 and L4, and 6 and a half minutes between L4 and L7.

Luckily, after that, it appears to have fixed itself. There were more than a dozen+ left eye images later in the sol that look completely normal, and several are already down for the next sol which look fine as well.

L8, 08:18:07 AM

L2, 08:19:30 AM
L4, 08:20:01 AM
L7, 08:20:32 AM

L2, 08:22:21 AM
L4, 08:24:10 AM
L7, 08:30:41 AM

I saw those when I updated today. It was scary to see the offset filter wheel. I don't like to see multiple issues taking place on the same appendage. Could the boosted motor voltage have caused some other problem?

I guess old age is starting to really set in with the poor critter.

It sounds like a temperature dependent problem, maybe. Arthritis, at any rate.
Note that quite decent 2-color images can be taken with the right camera 1 and 2 filters, comparable to 7 and 2 on the left camera.

Just to see, I composited the mis-filtered images as color images.

Most complex systems display failures in a probabalistic curve called the bathtub curve. Initially upon fielding of a system, there are a number of "infant mortality" failures. Testing in the lab actually catches most of them for a system like the rover, but we did see at least two on Mars (Oppy's joint heater and Spirit's wheel). These failures are usually caused by design or manufacturing faults. They form the left side of the bathtub.

Then there is usually a period of adulthood, where there are few failures. The steering failure for Oppy falls into this period though -- which may suggest that it is either a fluke caused by perhaps some debris getting into the mechanical system, or perhaps a latent manufacturing fault. This period is the floor of the bathtub.

As end of life approaches, failures increase, forming the right side of the bathtub. While we have too little data to make predictions at this point, one hard failure followed closely be an unrelated significant anomaly (I don't want to categorize this as a failure yet) is a cause for concern about where we are on the bathtub curve.

Hard to say though. We could have no more failures for the next year or more.

Scott

Spirit's wheel (the Sticky FR wheel) is actually back to nominal, and has been for almost a year. A few months of backwards driving sorted the situation totally.

Doug

Somehow, I didn't ever hear the final resolution of that. Thanks.

The bathtub curve really only applies to mechanical systems that can wear out, not to electronic components that tend to have rather constant failure rates. Of course there are lots of mechanical systems on the MER, and up to now they are the ones that have been showing signs of wear and incipient failure. Remember though that some vital electronic component can also fail at any time.

tty

I wonder what would happen to Pancam if this problem would occur while taking the Sun tracking pictures. If it only would overexpose the image that would be fine, but I'm afraid it might burn out the camera in a worst case scenario.

general
Oppy looks like a Swiss pirate with that eyepatch! cute!
"I'm on MARRRRRRRS - MeridiARRRRRRni PlARRRRRRRnum!"

Are the navcams blocked in any way when they are taking the sun tracking pictures with pancam?

Note there was one early-mission failure, maybe even during cruise stage: The temperature sensor on both rover's MiniTES calibration target failed due to a bonding failure. It was recognized as an expected problem before launch but too minor to delay the launches to fix, if I recall.