Mars Rover Spirit Mission Update Thread

[Leovinus]

This thread is for mission updates for Mars rover Spirit. <div class="Discussion_UserSignature"> </div>

 

[fangsheath]

Spirit suffers from being fairly far south of the equator. Mars is still moving farther from the sun and the sun angle will continue to become less favorable until late Sept. Rather than push the rover hard under these conditions, they may ease back and kind of coast through the Martian winter, to resume intense science when sunlight is in greater supply.<br /><br />Meanwhile, perhaps we will hear some analysis of the bright material here this week. I believe a press briefing is scheduled for Fri.

 

[JonClarke]

Let's have some guesses for what the white stuff is! <br /><br />My guess (in decreasing order of probability) is:<br /><br />1) Gypsum (or another similar sulphate like epsomite)<br /><br />2) Halite (or similar chloride)<br /><br />3) Carbonate (calcite, aragonite, magnesite, dolomite)<br /><br />4) Some really weird salt<br /><br />Jon <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>

 

[fangsheath]

A tantalizing tidbit is this recent quote from the MER website: "Scientists believe the rocks exposed in Hank's Hollow may have been generated or modified by water-rich fluids." It has already become apparent to me that water is a big part of the story of the Columbia Hills.<br /><br />Perhaps they will direct the rover to make its way up West Spur along the northern face of the ridgetop. This would keep the panels in a good orientation through the winter.

 

[thechemist]

Jon, <br />Let me translate the minerals you mentioned to chemicals for those of us who prefer this nomenclature <img src="/images/icons/smile.gif" /><br /><br />1) Gypsum <font color="orange"> CaSO4.2H2O </font>(or another similar sulphate like epsomite <font color="orange">MgSO4.7H2O </font> <br /><br />2) Halite <font color="orange"> NaCl </font>or similar chloride <font color="yellow"> Sylvite ?</font>font color=orange> KCl <br /><br />3) Carbonate (calcite <font color="orange">CaCO3 (hex)</font> aragonite<font color="orange"> CaCO3(orth)</font> magnesite<font color="orange"> MgCO3</font> dolomite<font color="orange"> CaMg(CO3)2 </font> <br /><br />4) Some really weird salt <font color="orange"> (insert your guess here ................... )</font> <br /><br />Now the sulfates in case 1) contain H2O molecules coordinated around the central cation of Ca++ or Mg++, and that would necessitate that water was present in their formation. How much would that water be though, is a question I cannot comment on. Maybe the next briefing will provide Nasa's view on that. <div class="Discussion_UserSignature"> <em>I feel better than James Brown.</em> </div>

 

[thechemist]

Some links for the geologically-challenged people like me <img src="/images/icons/smile.gif" /><br /><br /> Gypsum CaSO4.2H2O <br />Epsomite MgSO4.7H2O link 1 and link 2 <br /> Sulfates <br /> Carbonates <br /> Halite NaCl <div class="Discussion_UserSignature"> <em>I feel better than James Brown.</em> </div>

 

[Leovinus]

I know what NaCl is. <div class="Discussion_UserSignature"> </div>

 

[thechemist]

I didn't know what halite is, although halas=salt in greek. <div class="Discussion_UserSignature"> <em>I feel better than James Brown.</em> </div>

 

[centsworth_II]

<i>"I know what NaCl is."</i><br /><br />Don't sell yourself short. I'm sure you're familliar with epsom salt also, that stuff they've found so much of in Gusev, magnesium sulfate. <div class="Discussion_UserSignature"> </div>

 

[centsworth_II]

<i>"Perhaps they will direct the rover to make its way up West Spur along the northern face of the ridgetop. This would keep the panels in a good orientation through the winter."</i><br /> <br />I detect an ulterior motive here.<img src="/images/icons/smile.gif" /><br /><br />Of course it would be neat to see the view from up there, but I'm sure there are plenty of equally good, if not better places to winter over lower down. I think there are only two major factors to consider: <br />1. Stay out of the shade.<br />2. Optimze the orientation of solar panels to the sun.<br /><br />I don't think protection from wind is a factor. I don't know how you would protect from a dust storm while optimizing the other two factors.<br /><br />The only shade around is from the Columbia Hills so either climbing a low ridge or moving away from the hills should take care of this. The angle of the rover, and thus the panels, can be adjusted by parking on a ridge slope, or even a sand dune or crater rim.<br /><br />It may even be a good idea to move the rover twice a day, between optimum morning and optimum afternoon positions. This would keep the "joints" from getting stiff and further optimize exposure to the sun. <div class="Discussion_UserSignature"> </div>

 

[centsworth_II]

<i>"Let's have some guesses for what the white stuff is! <br />My guess (in decreasing order of probability) is: <br /><br />1) Gypsum (or another similar sulphate like epsomite) <br />2) Halite (or similar chloride) <br />3) Carbonate (calcite, aragonite, magnesite, dolomite) <br />4) Some really weird salt"</i> -- JonClarke<br /><br /><br />It will be <i>really</i> interesting to see how similar, or different, these materials are from those that Opportunity is finding. What they are, of course will have direct implications for how they got there. Spirit's water story may be getting every bit as exciting as Opportunity's!<br /><br />I hope they have a lot for us on this at the next briefing. At least NASA TV and the MER briefing sites now agree that this will be friday, July 16 at 10am pacific daylight savings time (1pm eastern daylight savings time). <div class="Discussion_UserSignature"> </div>

 

[centsworth_II]

I'll say this: Although Opportunty has found rocks containing very high amounts of sulphates, I have not seen any Opportunity image that shows what literally looks like crushed up salt -- or limestone!!! <div class="Discussion_UserSignature"> </div>

 

[mooware]

Thanks for the links, i'm very Geologically challenged.. A rock ****** so to speak..<br /><br />

 

[fangsheath]

Actually, I would have favored roving on to Lookout Point earlier, when the sun angle was better. But at this late date I think the ridgetop of West Spur provides the closest consistently north-facing area. Lookout Point is still at least a quarter of a mile away and north-facing slopes will be few and far between most of the way. Along the ridgetop, the vehicle can generate far more power and science targets are likely to be many.<br /><br />Keep in mind that the sun angle is already pretty lousy - a mere 53.3 degrees above the horizon at mid-day. That means we will need some pretty significant slopes. Tilting the vehicle toward the morning or afternoon sun will help very little, the angles are just lousy. <br /><br />I think running along the ridgetop is the best way to maximize the science until spring comes to the Columbia Hills.

 

[thechemist]

The view of the dark area would be lousy from the top !<br />However, who knows what lies ahead on the other side of the hill top ?<br />It's a win-win situation <img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> <em>I feel better than James Brown.</em> </div>

 

[robotical]

It's too bad that they didn't outfit Spirit with some sort of umbrella that they could have put over the solar panel. They could have put in into hibernation until conditions were favorable again. <div class="Discussion_UserSignature"> </div>

 

[remcook]

hehe...bad idea. How would the rover come out of its hibernation when the batteries are flat?

 

[thechemist]

According to yesterday's (13-7-4) Flight Director's Update , Spirit has been trying (albeit with minimal success) to mobilize the lubricant in its ailing wheel during the last sols.<br />Nothing about future plans though was mentioned. <div class="Discussion_UserSignature"> <em>I feel better than James Brown.</em> </div>

 

[fangsheath]

More than a tidbit comes from a BBC News story today. Ray Arvidson offers the following concerning the rocks at Hank's Hollow:<br /><br />"What we think is that these started out as basalts, but they've been corroded by groundwater. For example, they show these little balls on stalks. The balls we think used to be holes or vesicles in the volcanic rock, where chemical precipitate formed from groundwater. The surrounding rock has been eroded out, so you wind up with this inverted topography."<br /><br />http://news.bbc.co.uk/1/hi/sci/tech/3889263.stm<br /><br />It seems that JPL has an idea roughly similar to mine and intends to direct the rover to the ridgetop of West Spur, presumably using the north face of the ridgetop to tilt the panels northward.<br />

 

[decepticon]

Is the wheel thats sticking the wheel used for digging the trenches? <br /><br />It may be dirt jammed in the wheels.

 

[centsworth_II]

<i>"It seems that JPL has an idea roughly similar to mine and intends to direct the rover to the ridgetop of West Spur..."</i> -- fangsheath<br /><br />I have seen no change in the plan to explore the hills since Spirit arrived at their base a month ago. As I recall, as the rover approached the hills, the plan was to move from the base of the West Spur southward, following the base of the hills to some point where it would climb to Lookout Point. That plan was changed when Spirit arrived at the West Spur. At that time, it was decided to climb to the outcrops at the top of the West Spur.<br /><br />Fangsheath, you have the rover bypassing the outcrops of the West Spur and climbing Husband Hill. I have seen nothing to indicate that the plan has changed from investigating the outcrops of the West Spur and then continuing toward Lookout Point. The one wild card is what wintering over will entail and when this period must begin. But I haven't yet seen any specifics on this from JPL.<br /><br />The two top images here are taken from the 6/2 press release images as Spirit approached the hills. The top image shows Husband Hill in relation to the much more modest West Spur. I believe the "Talus Slope" in the top image matches up with the "Boulders" in the second. Also, I think the "Possible Outcrop" in the second image is just visable above the "WEST" in West Spur in the first image.<br /><br />The third, computer generated, image is harder to relate to the other two. It is of the hills seen from above. An orbiter's eye view. I have added yellow arrows which roughly relate to NASA's yellow arrows in the middle image. This assumes that the top + marks the target outcrops at the summit of the West Ridge. <br /><br />From the caption to the computer-generated 6/15 press release image ("cr <div class="Discussion_UserSignature"> </div>

 

[centsworth_II]

<i>"Is the wheel thats sticking the wheel used for digging the trenches?"</i> -- Decepticon<br /><br />As I recall, at the last MER press briefing, when the problem with the right front wheel was discussed, it was stated that a review of Spirit's trench digging showed that the left wheel was used in each case.<br /> <div class="Discussion_UserSignature"> </div>

 

[thechemist]

By observing today's Forward Hazcam images , it appears that Spirit is at the moment climbing a small slope going "in reverse gear", i.e. backwards. <div class="Discussion_UserSignature"> <em>I feel better than James Brown.</em> </div>

 

[centsworth_II]

I guess they're still trying to move the lubricant around in the wheel's inner workings. <div class="Discussion_UserSignature"> </div>

 

[spacechump]

Actually they are testing to see if driving backwards and just dragging the wheel along over longer driving stretches would be better then pushing the wheel through dirt. They did say that they wanted to test changing the duty cycle so that it would only spin about 10% of the time in relation to the other wheels. If all else fails they just lift that wheel off the ground and hope for the best in the drive.