I expect that the #1 alternative is at the bottom of the 3D Energy map – though we all hoped to get to the area above Korolev where the yellow arrow is, I believe we won’t have the power or time to do so. There are two rises that have North facing slopes in the #1 alternative spot, although they are fairly small. The image with marked ‘alternative b’ may be the spot on the energy map at bottom center.

I fear you are right about the conditions here, especially below HP in that valley - but, there is one possibility that stands out from photographic evidence - the top of HP is pretty bare. There's not much dust accumulation up there - so it's possible this rise we're looking at will have enough wind at some point for a cleaning job. But, I'd guess that will be many... many weeks away.

I'm not at all certain - but, I wouldn't be surprised to see Spirit doing a lot of 'deep sleep' in the coming months - perhaps starting more or less right away. We just don't know what the battery level is, or what the daily charge rate is right now. From what can be gleaned - it can't be very good.

Doug, I tend to agree on this rise being a possible candidate - the North side of it. Using Tesh's 'drive direction' image - IF (a big one) this is the goal - I'd say they'll scoot (limp) around to the North side of it, something like the green line suggests. Then I would expect later travel to the North side of another greater rise just to the west of it.

This wouldn't be a bad place to camp, and get the power up - as it may afford short visits for continued HP examination - something many people wanted to see.

There's two tidbits of information in a MarsDaily.com article today (at THIS LINK) - that winter is "still more than a month away" and that, "... minimum sunshine in the Martian winter is more than 100 days away."

Not much else is new in the article, and it restates the current goal of, "moving laterally to a different slope that should be easier to climb and will provide the maximum available sunlight for the rover's solar panels."

With being able to drive for only about an hour per day - with an average best-case advance of 20 feet per day, it would take roughly16 days to travel the estimated 100 meters to one of the three alternative sites they have mentioned. Expecting that turns, which are very tricky now, will take up to two days to negotiate - I'm guessing we won't see a safe spot until about four weeks from now - that is, if indeed we are headed for a spot "about 100 meters away."

Lets hope we can get some longer drives behind us, as soon as we get on this upcoming altenative path!

Uh oh... the 1 meter hovering object just zipped over in front of Spirit and was last seen entering the right front wheel area... it hasn't been seen since.

Tesh, if they want to do science, I just can not imagine them not making another try to get on McCool in some way.

Perhaps the alternate route around the sand will be through the somewhat rocky area just to the south of where the rover is now. Maybe the plan is to backtrack, then jog south, something like the green trace in the following...

(edit) The problem with that route may be some pretty steep climbs in spots.

Is there anyplace where they post the days power readings? I would sure like to know what they are... and I guess everyone else would too.

I'd be surprised too - if they actually returned to the top of HP... but, not if they go back to one of those rises just off HP. How long they stay there, or what route they take from there is what everyone wonders about.

I just hope they haven't given up on getting to better digs on the side of McCool - but, conditions and circumstance might preclude that. Whatever they decide, I'm sure it will be consistent with the best way to keep Spirit alive through the winter.

Clouds will not be an issue - nor sand storms (they happen during the summer.) Summer (wind storm time) on Mars begins about the middle of our July and ends about the middle of our Novermber (a swag, really.) The Summer soltice begins about our mid September.

Someone who has watched the dust devils on Mars can probably tell you about when they ended - and when they began.

Well - hope it isn’t so... but, from the latest images down, it appears Spirit is beating a hasty retreat back toward Home Plate... possibly to climb up on the sides of a couple of small rises to the southeast of the top of HP itself, near where Spirit was on Sol 774. Not the most exciting place to park for weeks on end - but, maybe the only choice under the conditions extant.

See possible emergency parking sites (red arcs) in the images below.

Say it isn’t so, and I’ll hope right along with you. But, I’m convinced the path is back to HP, otherwise why drive so far in the reverse direction, and not toward McCool?

If this is the plan, then we’re much closer to entering a period where we can’t get enough sun than we are to very cold weather... and it could be a very long, dull and perhaps dicey winter.

Don’t count Spirit out just yet. Yes we’ve reached Sol 800 - the day they hoped to be snugly ensconced on a slope of choice. But, there is yet a bit of time to get there...

Today it is April the 3rd on earth but on Mars it is Monday, the 16th of May - not even at the midpoint of Autumn in the southern hemisphere of Mars. The days and nights are colder, but far from the coldest days coming up just after the middle of June (Mars calendar) when Mars reaches apsides (pronounced ‘ap-si-deez’) at its furtherest point from the Sun. Winter actually begins in the southern hemisphere - on July 10th - Mars date, at the winter solstice. See the seasonal orbit plot below, with arrows point to where Spirit is now on the calendar, noting the middle of May, and the 63rd, or end of May - and also see THIS LINK, for an in depth look at the Mars calendar.

How much slack we have to get to the best site available - before things get very dicey - only the pros at NASA know. A wild guess might be at least another 15-20 days. Cutting it close? Yes. Possible? I’d think so... but driving results in the next 10 days will tell the tale. The biggest problem faced right now is the inability to drive but every other day - and traction!

My take as well, Doug. Dust! It's more likely that the 'frost' we saw before was composed of pure carbon dioxide - dry ice... with zero H2O involvement – no matter how much one might wish it were otherwise.

With the low gravity of Mars, the atmosphere is decreasing at a high rate - increased geometrically by solar bombardment, which further accelerates the break up of heavier atmospheric molecules and resultant lighter-ion planetary escape - water vapor being the most vulnerable to such radiation break up.

An aside, the idea that pools of surface water will be found on Mars is laughable. Liquid water cannot exist on Mars due to the fact that the atmospheric pressure (over ten times lower than that of earth – and getting lower) simply precludes the possibility.

Don't know about watt/hrs - but know the amount of drive time will be limited at most to perhaps 10 meters per drive-day... and drive days may be two to even three days apart. At least, that is what seems to be current reality.

It has been a periodic habit in the past that weekends see no drives - I think, giving the crew as well as Spirit a bit of rest. But, this past three days of almost no movement has taken place mid-week.

Perhaps they are still 'assessing the situation' - as well as charging batteries and waiting for satellite telcom support.

This is no 'route map' - but it is a map, such as it is... the Google Mars Map.

It doesn't work too well, doesn't go back to prior images well, and fails other desired features too - but, it is better than nothing, and better than others in some ways.

I have some friends that work at JPL in Pasadena - and am running the following thinking by them.

The speculation at NASA is that the motor brushes (one, or more, or all) ‘lost contact’ – causing the inoperative front wheel. That's certainly possible, but seems less likely, for a number of reasons that I won’t discuss here, than another cause.

That possibility is - we are seeing the result of another broken wire. The robotic arm on MER-B stopped working, NASA believes, due to a broken wire. Both that wire, and the wiring to the wheel on MER-A, must flex in a limited amount of space, and must do so repeatedly under very cold conditions – under which most metal-content conductors will suffer fracture-failure sooner or later.

Of course, I have near zero knowledge of the materials used to construct the conductor that provides power to the motor, nor how much stress is placed on the conductor via flexing. But, given that the motor stopped shortly after turning the wheels to line-up for satellite communication, I’m of the opinion that a conductor just reached the end of its ability to endure repeated flexing.

I don’t know for certain if they can raise or lower the amount of D/C power fed to the wheels, but I’m led to believe that they can. If they can, and if they can stop the power feed to all five working wheels, and raise to max, the current to the non-working wheel for measured milliseconds at a time – they may be able to restore the wheel to powered service, under very limited terms.

It is possible to ‘fuse’ some conductors back together, as I have done many times – but the bond is usually extremely weak, and normally would not suffer much flexing of any kind. However, I’ve seen such ‘emergency arc-bonds’ last a very surprising long time under difficult circumstances.

Tests being conducted at JPL will tell the real story soon enough. But, I think we can guess one part of it – flex-joint wiring is often very difficult to design, build and guarantee, particularly on Mars, beyond limited terms. That 90 day limit was set, to a large extent, for this and other relevant reasons.

Well, this is most interesting...

MarsDaily.com has a new article up (dated today) that has Steve Squyres saying that Spirit does not have to get to a north-facing slope to survive, but has to in order "to keep doing science." You can read the article HERE.

Tesh - it looks like a straight (approx.) 6 day drive (short ones) would get us to Doug's green zone...

That's a most interesting thread, Tesh... - particularly the image posted by SigurRosFan HERE which seems to indicate a possible fairly quick arrival in Doug's most green area. But, image compression plays tricks, too.

Looks like a 3 or 4 day six-wheel drive... perhaps 6 to 9 days, 5-wheeling it, but it may be several more. Doug thinks it possible - hopefully so do the drivers.

And I hope they do too! I'd very much like to see that 'Eastern Basin' - and sure many others would too.

Here's an interesting old topo map from OSU (2003) that we can tell isn't exactly accurate (from what we have seen) but it illustrates West Spur, and that Northern side of McCool that many think the best place to be is... in that blue circle somewhere.

Other possible sites (red circles) don't have the interest level, though they were considered 'safe' in the prior image from GSI, but they would certainly limit movement. It'll be very interesting to see which way we go...

I don't believe anyone here holds that impression at all.

Steve Squyers has said they want to be in safe territory by Sol 800 - he didn't say that the rover would die if it were not - and I think everyone understands that NASA at least tries to work within a margin of safety when they set published goals.

True, but hopefully not any time very soon... however, Sol 800 is near. Twenty days to reach safe haven - and they have a dead wheel to contend with. Somehow, I believe they will make-do - and the drama of the MER saga will continue to amaze.

Nor do I.

Spirit is at (about) the red square in the attached - with three almost equidistant slope choices nearby - but only one, behind Oberth, seems to offer the brighter green (better) sunny slopes. But, the best spot has to be climbed up to.

The other two spots are of a less bright green, and both look limited in suitability by comparison. But condition of the wheel will make the choices less clear though, as climbing will limit them.

It looks like immediately beyond Oberth may be one of the best North facing slopes nearest to Spirit. If the latest power numbers are correct, MER-A is operating on somewhat low power now, and without doubt the wheel problem helps (to a degree) make that problem worse.

If I don't miss my bet - I'd think they will act to get to any kind of nearby slope that tips the PP surface of Spirit Northward, and get the power level up before going much of any place else - while they fully assess the situation.

At this point I doubt we'll see much of any effort to climb too far up McCool - anywhere - in the next few days, and possibly through the winter, if they find the terrain above and behind Oberth satisfactory.

Here's a quicky of the 4 frame 774 pancam