PMA Actuator problem?, Diagnostics began sol 2257 Options

[Ron Hobbs]

The most recent Rover Update says:

"The PMA was found to be okay, which does not explain the earlier fault. So the project is continuing the investigation with more diagnostic tests."

That is good news ... I hope.

[James Sorenson]

That is indeed somewhat settling news....

[Burmese]

Scott Maxwell seems to think things have all cleared up, judging by his excited twits. Would be nice to have some actual detail...

[Poolio]

Smart engineers make apparent hardware failure vanish into thin air using brainpower. Have I mentioned that I love working with geniuses?

Yes, that sounds very promising. I especially like the word "apparent" used in that context.

[stevesliva]

Scott Maxwell seems to think things have all cleared up, judging by his excited twits.

Sounded more like he was referring to excited geniuses.

For the record:

After I make my TV show "Wow!" (showcasing wonders of natural world), I'm gonna make a "House"-like show about engineers. about 3 hours ago via Twitter for iPhone

There are lots of TV dramas where doctors or cops solve hard problems with detective work. Any shows where engineers do the same? Why not? about 3 hours ago via Twitter for iPhone

Smart engineers make apparent hardware failure vanish into thin air using brainpower. Have I mentioned that I love working with geniuses? about 3 hours ago via Twitter for iPhone

God *damn*, I love working with geniuses. Sometimes I get used to how smart my coworkers are, like the air I breathe. Today I remember. about 4 hours ago via Twitter for iPhone

[fredk]

Scott Maxwell seems to think things have all cleared up, judging by his excited twits.

Maybe the jpl engineers fixed the office coffee maker. That would get some people excited...

[Stu]

Re. the pause in images appearing on Exploratorium. I'm told by the site Webmaster that they're having issues getting the JPL software up and running properly on the new system. It's in hand.

[fredk]

Finally some real (but still unofficial) information. From here and here:

Had problem with Oppy's PMA azimuth motor last week; thought we'd lost it (so couldn't look left/right w/o turning).

Careful work showed PMA azimuth motor is probably fine; problem lies elsewhere. Double-checking hypothesis in today's plan.

"thought we'd lost it" - Yikes!

[Deimos]

Big problem, to puzzling behavior, to "nothing to see here, move along".

There is plenty of activity, including drive direction stuff, in the next plan at the pancam site. Among the first things to use the PMA, btw, is a set of sun images for attitude knowledge. Interestingly, the "mars quake" experiment could not be done while the rover was stationary. There was too much time on the IMU since the last fine-attitude check, and drift was a concern. No sun image = no seismology (that's got to be among the less intuitive MER connections).

This was still a reminder of the mortality of all the actuators and the fact that PMA az is the most overused. So there may be some things done less often. But at least it was not an actual sign of degraded PMA performance.

[BrianL]

And one more ScottTweet ™ on the subject:
Assuming all goes well, tomorrow we breathe a huge sigh of relief and go back to normal. Friday, more driving to Endeavour!

And there was much rejoicing.

[fredk]

Lot's of detail in the latest Oppy update:

Diagnostics were run on Sols 2259, 2261, 2262 and 2265 (June 1, 3, 4 and 8). In every case, the diagnostics indicated a healthy PMA azimuth actuator. Further investigation now suggests that the [Mini-TES] is the origin of the PMA symptom and that the PMA was just waiting on a signal from the Mini-TES that never arrived. Anomalous symptoms were observed from the Mini-TES earlier on Sol 2250 (May 23, 2010). Investigations are underway on the instrument. Meanwhile, final checkouts are being performed to return the PMA to normal use and to resume driving.

[fredk]

The new pics show a completely new pancam pointing direction for the first time since sol 2257:
http://marsrovers.jpl.nasa.gov/gallery/all...10P2869L2M1.JPG
http://marsrovers.jpl.nasa.gov/gallery/all...12P2869L2M1.JPG

[Zeke4ther]

well that's good news...

[Phil Stooke]

(crawling through desert) "Gasp! A drive, a drive... Gasp! Must have a drive..."

Phil

[fredk]

From the new rover update, some more details about what happened with the PMA:

By June 10, the troubleshooting engineers had homed in on the [Mini-TES] as the origin of the PMA symptom. Since the Mini-TES and the PMA are inherently 'bonded,' whenever the Mini-TES completes a task, it signals the PMA that it is finished and the PMA is free to move. The exchange is a kind of electronic “handshake” between the two devices. The PMA, it seems, was waiting on a signal from the Mini-TES that never arrived. Without the ‘handshake,’ it really couldn’t move.