Spirit cleaner? Options

[PaulM]

It has been suggested that without a cleaning event Spirit will not survive the next winter and that at Home Plate there is very little chance of a cleaning event.

My suggestion is that when Spirit has finished with the South side of Home plate then it should head for the "Promised Land" as soon as possible. I understand that the hill between Home Plate and the Promised land is fairly gentle and so is still climbable with 5 wheels.

Spirit experienced its first cleaning event at Larry's Lookout on the North facing slope of Husband Hill and so I am confident it would experience a similar cleaning event on the way to the promised land.

[djellison]

We've had cleaning events right where we are now, just before the dust storm. There's not much point in trying to out-guess Mars when it comes to cleaning events. Having confidence in one particular slope or orientation to provide cleaning just is not wise. Nor is the presumption that between now and winter, we can make it half a km south over uncertain terrain. It would be far more sensible to continue exploring home plate for now, and use any one of the local north facing slopes that are part of, or are around Home Plate - perhaps even the Pitchers mound

Doug

[Jeff7]

Hmm, I thought Spirit would look dustier than this...

Wow, it's still so dark there.

We've had cleaning events right where we are now, just before the dust storm. There's not much point in trying to out-guess Mars when it comes to cleaning events.
.....
Doug

Indeed. I was wary about Opportunity wandering into Victoria's dark streaks. Good thing I was wrong about that. Those things were like a Martian car wash.
The fact that Home Plate isn't completely covered in dust must also say something about the winds in this particular area. El Dorado would probably have been a death sentence - no argument about deposition or "clean streak" there. But Home Plate looks pretty clean. Hopefully in that regard, Spirit will follow in its footsteps.

[PaulM]

If I remember rightly Steve Squyres said about 6 months ago that Spirit would be finished with Home Plate within 6 months and would then be moving on. I think that I did read that the Pitchers Mound (or at least Goddard) was on Spirit's planned route.

What I would like to see however is Spirit moving onto a decent hill South of the Pitcher's Mound (on the way to the Promised Land) before the next Winter. My reason for this is the contrast between what Spirit achieved on the large hill known as the Western Spur in its first Winter and how little it achieved on the tiny Lowe Ridge last Winter.

I realise that circumstances forced a rapid drive to the safety of Lowe Ridge last Winter. However, I hope that with more planning time available Spirit will be on a nice North facing hill before next Winter and will have several 100s of metres of gentle slopes ahead of it to explore during the 6 months of the Martian Winter.

The Southern end of Home Plate remains for Spirit to explore. However I hope that Spirit will be finished with Home Plate within the next 3 months or so.

[djellison]

We had months and months of planning when it came to the drive to McCool hill last winter - but we didn't make it because of what Mars threw at us. And yes - the plan may have been to move on 6 months later...6 months ago - BUT - that was before a near 3 month hiatus because of the global dust storm.

Spirit can not traverse steep slopes anymore. There isn't anywhere with a lot of gentle slope all in the same direction - apart from McCool hill, and we know what happened last time we tried to get there.

The reason it had a productive winter in its first year was because it never had less than 300 Whrs - enough for all the housekeeping plus driving and science. Second time around, it dropped to less than 250 and only had 5 wheel drive - enough for housekeeping and...that's about it. Even if they HAD made it to McCool hill, they wouldn't have been able to climb it in any way - it's unlikely they would have had enough power to even trundle around the gentle slopes at the bottom of the hill.

There are some small hillocks to the south - including the odd interesting one....but if you set out for them NOW - with the potential for Tyrone like sand traps on route - you would run a very large risk of getting stuck out on flat terrain somewhere south of Home Plate and dying because of a lack of slope. 10-20m/sol is all you can expect - and even when 'sprinting' one can typically expect one sol in two or three to be a driving sol.

From a scientific persepctive - yes - the terrain to the South looks interesting, but I would have though the prudent option from the bigger-picture persepctive is to stay comparatively local this winter, and, if we have a healthy vehicle next spring, set out south at that point. Realistically - we've barely started exploring home plate itself. There's many months of science to be done here before electing to move off.

Doug

[climber]

Agree on your plan Doug. I'm a bit lost of where we are regarding seasons on Mars. If I'm right we're only a few days away from the 2nd Marsian year on Mars for Spirit but I cannot still figure out when we'll have to start to ibernate. Another, what, 200 sols ?

[djellison]

Currently it's Mid Southern Hemisphere Summer - the sun is 85.5 degrees above the horizon at noon for Spirit.

100 sols from now - that figure will be 74 degrees and it will be Early Autumn
200 sols from now - 56 degrees, Mid Autumn
300 sols from now - 50 degrees, Early Winter
400 sols from now - 60 degrees, Mid Winter
500 sols from now - 81 degrees - Early Spring.

Basically it's the 150 to 450 sol's in the future period that will be the worst of it

That's all using the mars24 applet - our resident Purveyor of Whr's might be able to do a better job

Doug

Off topic posts from after 30 October moved to new thread:
http://www.unmannedspaceflight.com/index.php?showtopic=4837

Alan