I don't think that's a damaging scenario - Li-Ion's don't have memory issues like some older technologies - but I think the tie in is that a little bit of battery activity is possibly required to keep them warm enough to avoid damage.

Doug

There's about a 100-1 'lurk' ratio at a best guess - i.e. for each regularly contributing member there's about 100 unique visitors per month.

I have spoken to people who would be classified as knowledgeable people who like the place, visit regularly, but don't contribute because they don't have the time or are worried about saying things that they shouldn't etc. BUT - they still enjoy the place and will occasionally send an email or put something on a website somewhere so we can keep ourselves informed..informally.

There is a cut off made in terms of subject matter and quality. If that cut off retains more high quality activity than it eliminates - then it's doing the right thing.

At the end of the day - this isn't the only place in the world to talk about this stuff - there are others - and if people are not happy with the 'slice' made on the types of discussion or people involved here, they can always contribute to other forums (I visit the BAUT forums a lot for instance - for stuff that wouldn't quite fit here )

I've had some fairly nasty emails and get called some fairly nasty things on other forums because of it - but it's a price worth paying for the positive feedback that outweighs it significantly.

Doug

We make no such claims here . It's the exact opposite - intentionally excluding of certain types of discussions or types of people.

Doug

As long as the rover is internally warm enough, then there shouldn't be any component failures - it doesn't really matter how hot it gets - as long as it's not too hot.

The challenge is this. Is combination of whatever energy they are using inside the WEB plus the 8w of RHU's (two on the rem, 6 on the bettery) enough to put enough heat into the WEB to keep the night min.temp. above whatever temperature would cause a failures?

Given that the use of deep sleep has been a regular thing - and that survival heaters were used only during the very coldest nights with Spirit - and that graph suggests 15-20 degrees warmer minimums - then I don't see it as a problem.

The phase diagram shows that the window for liquid water at these pressures is very small. It's quite likely that these conditions putting both the liquid AND solid phase out of the question for much of the day.

Doug

Indeed - Dr Burt agreed it was the right thing to do - it was going in circles and getting no futher. The same is true here - but given that this thread has been going for less time, I thought I'd give it a little longer before bringing it to a close.

In both cases - the threads have been more of a cyclical soap-box rather than scientific debate - and that's not something I want at UMSF.

Doug

The BBC News website asked for 100 word potter stories - this had me nearly wetting myself

"By the way, Harry," said Professor Dumbledore halfway through book six, "a prophecy says that you alone can defeat evil Lord Voldemort. That's why he keeps trying to kill you. You must destroy all seven pieces of his soul, and you've got one book left to do it in. Don't expect any help from me; I'll be dramatically murdered in two chapters' time. Besides that, there's exams to pass and hormonal stirrings to contend with. Now do you wish you'd gone to that Muggle comprehensive?"

Don't draw a conclusion on the exposure from the raw JPGS. More likely is a bad stretching algorythm during the processing from data to JPG. There are too many links in the chain to assume a dark JPG is indicative of anything wrong with the operation of the camera.

Doug

I was going to queue at our local Borders to get one for Helen ( she didn't want to run the risk of someone flicking to the back and screaming out spoilers at the store at 5 past midnight ) - BUT - the queue at Borders was HUGE, probably a couple of hundred people, wrapped around the whole store - so I went to the supermarket opposite and was 11th in the queue, the manager of the store came out with a tray of champagne and orange juice to keep us happy. 20 minutes later I was in, grabbed a copy, checked out using the self-checkout machine, and was out of store 92 seconds after the book went on sale ( according to the receipt) and home by 00:10.

Helen is now firmly encamped in the spare room reading it - fully intending to finish it today. I'm not in as much of a hurry - but do want to see the series to the end having read the others. Personally I was hoping that JKR would fool us all and produce book 7 as a 12 page pamphlet.

Doug

The MCS stuff is great as well - really good to see what could be an outreach-challenging instrument get good airtime via TPS.

Doug

I am going to do the same thing to this thread now as I have planned to do in another, similar thread - close it.

It's going around in circles, it's getting nowhere, it should have been healthy discusion, but for whatever reason it's not happened that way - it's frankly damaging to the forum.

dburt's written more than 41,000 words. If that's not going to get a point across, nothing will.

If people wish to discuss his Meridiani theory further, then please do so elsewhere or via email.

Posts in other threads on this subject will be deleted - as a subject it's been exhausted with this thread.

Doug

It'll last for years and years and years - like NH's or the Voyager ones.

Doug

I saw videos of that electrostatic mechanism at the IAC'06 in Valencia - it was brilliant. Far FAR better than any mechanical system.

Doug

You've had ten days to bring some sound science to your theory - and have avoided or found it impossible to do so. You've repeatedly avoided ignored the difficult issues around it.

I'm going to take a leaf out of the BAUT rule book and put a time limit on this thread. I'll give it 5 more days – and then close it. Long enough for you to bring some science to it if you're ever going to, but short enough so we can all stop wasting our time if you're not.

If you're looking for somewhere to carry on talking about it thereafter, I would highly recommend the BAUT forum - as it's exceptionally tolerant of theories that are against the mainstream, but within well established rules.

Doug

Get rid of the brush, get rid of the arrays use an RTG and you've fine. And remember - there is another short-link in the chain. People. You can't have a rover that operates 24/7 - not least of all because you'd have to take floodlights with you - but also because you need downtime for the operations team to design the next sols sequence based on the results of the previous sequence. The downtime inbetween can be used a little like the rover's nights have been from time to time - APXS/Mossbauer integrations ( in the case of MSL - APXS integrations and the SAM suite )

You want to add arrays, a big arm with a brush ( which is more mass, more volume, more money )
That RTG is going to be producing X Watts, every hour of every sol, and that figure is more than is required to operate the vehicle. There isn't any sense in adding a further power source when you could spend the mass, volume and money elsewhere (like, a slightly larger RTG for instance). The very point of the RTG is that it gives a perfectly predictable, reliable power source for as long as you need it (over a primary mission of a martian year) - it's eliminates every down-side of the solar arrays in one - excuse the pun - sweep.
Doug

A couple of decades.

Doug

For those wondering - that's Pete, previously seen here:
http://www.unmannedspaceflight.com/index.php?showtopic=4139



Doug

Remember - this isn't a snapshot of the whole planet at one time - it's slices of planet at 3pm local - and thus you get lighting effects from one side of each stripe to the other.

Doug

Two idiotically childish posts have been removed from this thread. They know who they are. If you want to have a pathetic argument - do it somewhere else.

Doug

No - not surface - the near SUB surface - and in one case speculated as being places that have been recently exhumed.

They're talking about alteration by thin films of water. You're talking about the deposition of hematite and sulphate rocks. If you're getting water deposition from frost - then it's pure water - not the sort of water that could leave rocks behind.

Dominating Meridiani is erosion. It's clear to see from the imagery. How you can propose that the surface is growing, and burrying Berries - I just don't know.

Doug

Interesting paper regarding erosion rates :

http://trs-new.jpl.nasa.gov/dspace/handle/2014/40227

You have to explain why this entire paper is utterly wrong to begin making sense of your theory Kye. You've got to stop pretending a theory can hang on a contraindication but at the same time ignore it's own contraindications - such as that paper.

Dou

To be fair - it's more like 10.2 Ahrs down to about 8 Ahrs - so from 600 Whrs to 470 Whrs at the very worst - but given that it's not had 1000+ FULL cycles - but partial cycles, and in good power states, probably less than 1/3rd cycle per sol - I would argue for >500Whrs of battery capacity.

Doug

You're avoiding it. You couldn't be avoiding it more if you tried. You're avoiding the fundamental point of your theory..

how

In light of all the evidence I've shown ( stalks, different surface elemental compositions, different spherule sizes and distributions, etc etc)... the only thing that could be considered the heart of the matter is...

how?

Until you tackle that issue - we're all wasting our time. Sorry to be so blunt about it - but that's the truth.

Doug

Back of envelope maths...

A full battery is 600 Whrs.

Basic spirit ops during winter were 240 Whrs

Opportunity currently 150-200 Whrs ( let's say average of 175 )

Battery Out In End
600 240 175 535
535 240 175 470
470 240 175 405
405 240 175 340
340 240 175 275
275 240 175 210
210 240 175 145
145 240 175 80
80 240 175 15
15 240 175 -50


etc etc


Doug

Actually - they've started culling them. According to Mark, they tried an uplink on 1237 to tell the rover to NOT to that afternoon's Odyssey pass- but the uplink didn't go through

(my best guess - an atmosphere rammed full of ferric dust does things to radio waves)

Doug