Spirit cleaner? Options

[centsworth_II]

I recently noticed some DDs apparently moving toward Spirit, which seems to be an unusual direction for them.

Well, it's got to be asked : Was it a DD or a wind gust that cleaned Spirit?
Do we know if this one happened at night, or during the day?

[elakdawalla]

I was actually wondering about that. How finely can they pinpoint when the cleaning event happened? With what time frequency are the solar panel outputs measured during the day? Obviously it isn't measured at night, so if it happened at night, I'm guessing all they can say is that it happened at night. When were the pancam images taken that bracket the event?

--Emily

[alan]

This is the best I could get out of Autostitch

[dvandorn]

Yeah -- you can see she's cleaner than she was, but it wasn't a full cleaning event. The panels near the ends of the wings are still pretty dirty.

Still, any cleaning whatsoever at this point is a gift, and I accept it gladly...

-the other Doug

[ElkGroveDan]

As I recall these events aren't isolated ones. I bet we'll hear about another one in a few weeks bringing it up to 825 whrs. Didn't we reach a point the last time where they were keeping her up all night to shed excess heat from the return to 900 whr?

[Tom Tamlyn]

I hope your prediction is correct, but wasn't Spirit at a higher, more windy elevation when the previous series of cleaning events took place?

TTT

[climber]

I hope your prediction is correct, but wasn't Spirit at a higher, more windy elevation when the previous series of cleaning events took place?

TTT

Yep, she was right in a pass when she get the "big" cleaning event which, to me, think logical. By any mean, yes, she was much higher.

[edstrick]

"I doubt they get engineering data at a high rate all the time the puter is powered up. Maybe not much or any when it's more or less on standby. Generally, I think events will probably happen between blocks of data.

Anything after sunset and before sunrise can't be detected by solar power changes regardless of whether the rover is taking data or not!

[helvick]

I've asked about the engineering data before (and I was specifically looking for the periodic Solar Panel output currents) but was told that that's not going to get published. As I understand it engineering data would have to be stringently reviewed to make sure it didn't breach ITAR and that would be too much paperwork for not enough end user benefit and to be fair that was a perfectly reasonable answer.

I haven't been able to find any data on the sampling period for this either so I can't say if it is taken more frequently than once per day. Prior cleaning events have generally been vague about the precise timing - generally indicating that power levels have increased between sols so it is possible that only one sample measurement is recorded per sol.

[CosmicRocker]

That doesn't make sense to me. I would have thought that engineering data consumes a relatively small amount of bandwidth compared to images and spectrometers. I think I appreciate that there are many sensor feeds, but surely they monitor panel output more often than once/sol! Where am I going wrong?

[RobertEB]

I was looking at the picture above and I noticed the hinges when a thought hit me. Would closing the solar panels and opening them back up help knock the dust off. Maybe they could even shake them a little.

The only problems I see are, one- dumping the dust elsewhere on the rover. Two- the possibility of not being able to open them again.

[Tom Tamlyn]

Pete Theisinger was asked about closing the solar panels in an effort to get rid of dust on a webcast that I've seen. (I believe that it was during the Q&A after a von Kármán Lecture given before the rovers landed.)

In light of the risk that the panels would not reopen, he said (to paraphrase) that he could not conceive of a circumstance that would justify taking such a risk. And of course the dust is "sticky," so the potential benefit might be very little.

TTT

[centsworth_II]

...closing the solar panels...

I'd find it hard to believe that there is even a way to do this.
I would assume they were designed to lock in the open position.
I'm sure it would take a whole different design, with different latches,
and motors to accomplish this. The intent was to open the panels
and leave them open. The design would have been the minimum
required to do this reliably and nowhere near as complex as that
needed to reclose and reopen them.

[RobertEB]

I don't know if they lock in place or not. I would probably design them to do so if I was in charge.

If they don't perhaps they could try shaking the dust off as a last ditch effort.

However, when Spirit does finally die, I would hate to see her die with her panels stuck up. Doesn't seem fitting for a rover that has done so much.

When humans walk up to her one day in the future, I want them to see her sitting on Home Plate like she was as an explorer.

[Guest_Analyst_*]

As I understand it engineering data would have to be stringently reviewed to make sure it didn't breach ITAR and that would be too much paperwork for not enough end user benefit and to be fair that was a perfectly reasonable answer.

ITAR again. Well, it could be helpful to build solar powered nuclear bombs roving around. I am sure this could be helpful information for the ExoMars designers.
In the long term, ITAR will reduce the capabilities of the US aerospace industry to be competitive. Sorry, I had to say this.

Analyst