[X] My Assistant

[Bill Harris]

I'm not engineer, but I currently fly remote control aircraft with geared electric motors and in earlier incarnations worked with telescope gear drives. The IDD actuators are likely geared stepping motors and over time the gear train lubricants age and move away from critical points and, well, quit lubricating.

There are four actuators in the arm: a "shoulder joint" which provides left-right motion and near by is another joint which allows the arm to move forward-backward. The arm has two sections and the middle joint is like an elbow and that actuator provides more range of motion. The fourth actuator is like a wrist at the tool carrier and aligns the tool with the surface being thwacked. Of course, a fifth motor rotates the tool holder to select the proper tool.

Of the actuators, I'd figure that the first left-right shoulder joint is least critical and it could be left in one position and hthe arm might be stowed in a non-standard position without it.

I'm sure that there'll be a workaround...

--Bill

[ElkGroveDan]

Among the remaining possibilities is that, after working more than seven times longer than originally planned, the lubrication is degrading...."

If this is the problem then it certainly didn't occur suddenly. I am forced to wonder if they haven't noticed balky performance of that joint. Have there been current spikes during it's operation? Or can they even track that sort of thing? It would sure help to watch for similar problems on Spirit and other similarly lubricated joints on both rovers.

[odave]

Something is moving in these two FWD Hazcam frames.

1F186783443ESF64KCP1157L0M1.JPG

1F186783562ESF64KCP1157R0M1.JPG

This looks like a left-right motion to me, which would be produced from the azimuth/shoulder motor - correct?

Are they getting a little motion before the stall now?

Or is that not part of the IDD?

[akuo]

Something is moving in these two FWD Hazcam frames.

1F186783443ESF64KCP1157L0M1.JPG

1F186783562ESF64KCP1157R0M1.JPG

Yeah, something is moving - our point of view. Those are from left and right hazcams :-P
(L in the 4th last letter of the filename tells its the left hazcam, R is right)

[odave]

[Homer]

D'OH

[/Homer]

[jamescanvin]

I think I'm right in saying that the joint that has the problem (the shoulder) is the one with the stuck heater, right?

This would mean that the joint has had a lot more heating than the one on Spirit and what it was designed for. Could be responsible for possible problems with lubrication or any number of other unforseen things.

Or maybe not, just idle speculation...

James

[RNeuhaus]

Long time ago, when Oppy was inspecting inside the Endurance Crater, it had problems with a night with heating switch . It were drawing too much current so it was turned off during night sleeps. So Oppy has spent many days with deep sleeping mode without any heating for IDD.

Then, it might have accelerated the aging process of lubrication parts in joint arms. Otherwise, Spirit has undergone less often as deep sleep than Oppy so Spirit's joint arm is still working and is lasting longer than Oppy.

I am afraid if that problem is due to lack of lubricant on the joint arms. Then, there is no available solution to that unless "someone" is able to fly to where is Oppy to drip some valuable lubricant on the arm joints.

Rodolfo.

[dvandorn]

"mmmmrrrrllll mmmmcccnnnn."

"What did she say?"

"I think she said 'oil can'!"

Oppy is in a place where she can accumulate rust without ever getting wet...

-the other Doug

[Toma B]

Tom Tamlyn , CosmicRocker...looks like our criticism has been noticed by MER site moderators...
Updates are back where they used to be...



BTW it's just one more proof that NASA/JPL guys are watching this forum...if someone had any douth...

[Toma B]

I have just one more question:
Why are they staying in that one place??? They are unable to unstow IDD arm ( at least for now) so why aren’t they do one thing that they can do with $400M robotic vehicle on Mars…..DRIVE!!!!

Maybe they will find a way to fix this problem once but for now staying in that one place is, despite of that wonderful outcrop , waist of time…isn’t it?

[djellison]

Because they're sat right infront of some fantastic layering which they want to investigate.

Doug

[Toma B]

Because they're sat right infront of some fantastic layering which they want to investigate.

I know that, but consider how many fantastic "rocks","layerings","outcrops" are ahead of us...
There is one only 20-30 meters away...then there is that Victoria crater we all want to see...some of us in this lifetime...
Woud it be souch a terrible los if we skip this one?
Toma B.

[djellison]

It's the same argument that's been had a thousand times. Yes - it's nice to make progress, but yes - one has to take whatever science is infront of you because the rover may not wake up tomorrow.

For all we know - driving might worsen the IDD situation. The IDD may not even be properly parked, and driving could cause irreperable damage.

Yes - it looks like there are some nice outcrops ahead, but we already have one right infront of us - that we are already 'at' and already poised to investigate, with routines for the IDD already written. I can see the case for driving on, but I can see why there
1) may be reasons that we can't drove on
2) are good reasons to stay put till the IDD is fixed, or declared unuseable.

Doug

[sranderson]

I know that, but consider how many fantastic "rocks","layerings","outcrops" are ahead of us...
There is one only 20-30 meters away...then there is that Victoria crater we all want to see...some of us in this lifetime...
Woud it be souch a terrible los if we skip this one?
Toma B.

If you were a geologist, investigating never-before-seen-by-man northern Arizona, would you spend your limited time investigating outcrops near Flagstaff, or would you try to drive your jalopy to the Grand Canyon, even though it may fail on the way? Where would you be more likely to get detailed information on geology from eons past?

Scott

[djellison]

It look as though they're making the most of the pseudo 'down' time anyway - a full 360 Pancam mosaic, and a deck pan. They're already AT new terrain. Yes - it'd be nice to be doing 200m/sol and be at Victoria by Christmas, but sometimes things are just not possible.

Remember - for all we know, the IDD may have moved just enough to be considered un-parked and thus driving CAN'T be done. (infact, I think that's quite likely) - read the updates and it says that it stayed park on the first sol, then the second sol it recorded a small ammount of motion.

To make the anaology more appropriate, would you head out for the grand canyon to do geology without first checking you had your rock hammer and lens in your bag, and that your bag wasnt going to fall off the back of the truck on the way? Oh - and the Truck is parked on top of the first significant layering you've seen in 200 sols... get my point?

Yes - I can see why some would say "get moving" - but I can see why it may not even be possible ( so the argument is mute ) and I can see why they would want to look at what they're parked infront of.

Doug