As 2012 approaches…

Firstly – welcome back, everyone! Hope you all had a *fantastic* Christmas!

2012 is just over there now, on the horizon, peeking at us coyly, and soon 2011 will be consigned to history. As she enters the final days of 2011, Oppy is still at the top of Cape York and still taking a good look at the rocks and dust around her wheels. So, not much movement to report, but a couple of new views of the ground immediately around the rover…

Another thing Oppy has been doing recently is taking a lot – and I mean a LOT – of images of her own back, or “deck”, to check-out just how dusty she’s become. Here’s a colour image I made, showing one small section of the deck…

Now obviously that’s dusty, but you can’t tell just how dusty it is unless you compare it with a picture taken waaay back. I couldn’t find that *exact* section of the deck when I did a quick search, so instead here’s a composite of cropped sections of two images taken from the official calibrated Pancam images page… the top image was taken 19 days after Oppy landed, the bottom one , 2776 days later…

Now that’s a heck of a difference, isn’t it? Oppy really, really could do with a good strong gust of martian wind to give her a good clean…

That’s all for now, check back soon for more pics.

UPDATE:

A couple of people have left comments wondering why the MERs weren’t fitted with brushes or wipers, or something like that, to enable the decks to be cleaned of dust when it gets so thick it begins to affect their performance. Good question. I decided there was really only one person to ask… Steve Squyres himself…

Early in the project, we looked at all kinds of mechanisms for cleaning the solar arrays. We looked at windshield wipers. We looked at compressed gas jets. My favorite was one that had transparent plastic on rollers… when the plastic got dirty we’d turn the rollers and bring fresh clean plastic into position. 
 
The problem with all of these solutions was that they all required big heavy mechanical things to implement them. That windshield wiper, for example, would have weighed more than the instrument arm and all the instruments on it. And our rover was already as big and heavy as we could allow it to be. We simply had no margin to add that much mass, not to mention all the additional complexity of more motors, more gearboxes, more wires, etc.
 
So instead of adding a big complicated mechanical system, we took a much simpler approach: We oversized the solar arrays. Those solar arrays are bigger than they needed to be to give us our required 90-sol mission. In fact, when we first landed they produced so much power that we had to shut the rover down during the day to keep it from overheating. But the oversized arrays have paid off for us in a very big way… a mission duration that otherwise would have been measured in months has become many years. 
 
Sometimes the simple brute-force solutions are the best ones. 
 
 
So, there you go. :-)
About these ads
This entry was posted in Uncategorized. Bookmark the permalink.

5 Responses to As 2012 approaches…

  1. Chris says:

    It wouldn’t have cost much to install a fan on the deck!

  2. Ted Lamoureux says:

    You know that’s quite a comparison…I always thought that some of this could have been remedied by having installed something similar to car windshield wipers at a couple of strategic spots on the edge of the solar panels. Perhaps equipped with a line of fine, light brushes that with one sweep would “clean” or help “clear” the panels of some of the dust. I’m sure it would not be too difficult to implement in future missions. But I’m not an engineer so I don’t know if its even feasible…still it seems a simple solution to this nagging problem.

  3. vanDivX says:

    My idea was to have solar panels that swivel to enable pointing them to sun as needed which would come handy for winter months when we wouldn’t have to look for the slope to tilt them to the sun.

    Now if the swivel motion could be 180 (but even 90 degrees would suffice), the panels could be flipped upside down once in a while to shake at least some of the dust off (maybe while driving over some rough terrain to shake it loose. And ideally both sides (top & bottom) of panels would be solar sensitive (this could be utilized even if the panels tilted only 90 degrees). Now if that were so, perhaps the bottom side of panels would generate at least some power from the light reflected from the ground? But even if that weren’t the case, the panels could be made a bit smaller now that the accumulated dust could be shaken off plus the panels could be more efficiently pointed to the sun so they wouldn’t need to be quite as large. And weight saving due to smaller size of panels would compensate for the weight of the swivel mechanism.

    I would also consider mounting some fixed solar cells on the vertical casing of the rover body enclosure – that would catch well setting sun rays at least from one side at a time… not sure how that would add weight. I suppose that wouldn’t add too much because these fixed solar panels would be mounted on the existing substructure of the body casing and so wouldn’t add as much weight as those self-supporting panels we have now.

    And if we had surplus power, why not put some led light on the rover and row at night of use those leds to light up some close up target to enable the camera to take some more naturally looking pictures – like what we would see if we were actually there (not really sure if that would help any when it comes to colors).

  4. vanDivX says:

    Also if the panels were light sensitive on both sides you could keep one side down most of the time when its dusty in the air to keep it as clean as possible and flip it up for the winter months only when you need all the power you can get and perhaps you don’t get dusty storms during the winter time?

    Of course these ideas are now mute, given that Curiosity is on its way by now and who knows when some next rower will be in the making. As to current rower limitations, we have to keep in mind they were counted on to be going for ninety days plus maybe some months extra, nobody thought they would last much longer, likely not past the first winter in any case.

  5. Ted Lamoureux says:

    Thanks for asking the question to Steve Squire. I really appreciate it. I also like that guy. He seems like a fine person from all the TV interviews I have seen him do.
    Thanks again for asking him.

    All the best.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s