and http://marsrovers.jpl.nasa.gov/newsroom/pr.../20080215a.html

Strong enough to maintain pressure on orbit, but weak enough to break apart on re-entry is probably a specification overlap that doesn't exist I would imagine.

Doug

This is something that both Jim Bell and I think, which typifies just how much a part of our lives those two machines have become.

I can't remember what my life was like before them.

Doug

The was an old rover called Oppy
Who's Rat mechanism was choppy
She was stuck in some dunes
Just running of fumes
For long term drive planning, that's sloppy.

It's taken me ages to figure out how to say ' Saa Yoooz ' . Luna cod (which is what I've said) may need more research :0

I bet Jim Oberg would know.

Doug

Endurance to Victoria was a sprint. It had technical halts, but so would the drive to Ithaca. It had very very few science stops of any significance. Over long distances of mixed terrain - that's as good as it gets.

It took 22 months to reach Victoria. There is no reason to suggest a more rapid rate of progress could be made on the way to Ithaca. 40-50 months (or roughly 3 to 4 years) is far more realistic. Give the likelihood of one or more serious mechanical failures on the way, a conservative estimate could be at least double that.

That route in particular isn't great. South East isn't really a nice option. NE is far more navigable.

Doug

My copy is now on it's way, along with Planetary Landers and Entry Probed

Doug

Well - here's the Spirit story. It failed a bit, then we nearly stopped using it, then it was fine for a while, then it suddenly died totally. It was, perhaps coincidentally, the trenching wheel that died - but all 6 wheels did a whole LOT of trenching on Opportunity. Opportunity has a stuck steering actuator that may or may not make a contribution. Opportunity has done a lot more mileage, but probably less climbing, Spirit has had hasher thermal cycles, but Opportunity's probably had more jarring driving over open rock. To infer 'we've got X sols' or, 'X km' from that is a random guess.

Doug

You don't really. What I've said is that there are many valid science targets in the Victoria aria, even back up to Erebus etc. Once all of those are exhausted and no other options are available, then a not-quite-utterly-horrific-but-still-idiotically-lengthy route to Ithaca would be a valid next step, if for no other reason than to cover ground in any direction.

Doug

Another year or two, or maybe just another month or two, or maybe tomorrow. We don't know. We're guessing. You should be thinking km's, not years though I think. What is most probably is that it will fail at some point, and the middle of a dune field probably isn't the best place for it to happen.

Doug

It's from here : http://hrscview.fu-berlin.de/cgi-bin/ion-p?page=entry.ion

Doug

And how many km. (answer, not that many)

Now how many km to Ithaca. (answer, many )

So, if you want to consider a 20km, then yes - there are real reasons to anticipate this happening 'sooner' than it did on Spirit.

Doug

Actually - that's a good point. 1183_0000 HRSC ob has Vic and Ithaca in it.

Meanwhile, from HRSC view. - indicating something like 250m of elevation change from the rim to the floor. I'll have an animation session with it tomorrow night.

Doug

No, we don't. We have quite a lot of terrain covered : http://hirise.lpl.arizona.edu/PSP_004289_1780 : but not all of it. Given our recent news of early symptoms of wheel failure, my opinion on this is firmer than ever before. If, after exhausting every possible scientific target in and around the Victoria annulus there are genuinely no other valid options, then why not. But I don't see that happening before the wheel failure is likely to occur, and at that point, it is, imho, a fundamentally impossible challenge. I see little point in abandoning accessible science for a target that all sensible consideration would deem inaccessible. With a brand new rover without 12km on the clock (2000% of it's design life), maybe, just maybe, it would be possible - and even if it were, it took two years to get from Endurance to Victoria. Do the maths. In a romantic world without technical failures and dune fields, bring it on. Sadly, that's not the case, and I genuinely, honestly believe people who suggest it should be done before every other possible option has been thoroughly explored are sending the rover to an earlier-than-necessary death.

http://global-data.mars.asu.edu/ctx/img/P0...1780_XI_02S005W and http://global-data.mars.asu.edu/ctx/img/P0...1780_XI_02S005W probably offer the best overview of the route. The easy 200m/sol terrain is visible as a slightly lighter tone that extends from Endurance for several km north - in a band that runs East-West. There is etched terrain similar to that of the Erebus-to-Beagle run (20-50m/sol with occasional dune fields ) runs west for a dozen KM, then south for a couple of dozen KM. I would suggest that might make more sense than anything else if you wanted to cover some ground.

But, lets be honest, all we're really doing is guessing. If we knew all the plans, it wouldn't be anywhere near as exciting

Doug

(PS - on the flip side, screw it - lets follow the thin ribbon of etched terrain E, then NE, the E, then S toward Ithaca that Ustrax suggested a long time ago. POinting SE and hitting 'go' would still be a bad idea)

Hopefully Mike C will be able to chip in. It's a stunning camera - great images, and hopefully, a global map in a couple of years

Doug

Yeah - that depends on the criticality of the imagery. The 'end' imagery would be considered most important, so would be higher up the list to download than the rest.

Doug

Have you tried experimenting with the -sNNNN tag for img2png?



Doug

Just so no one thinks I've totally forgotten about this - Helen and I went out to Cambridgeshire today to see James et.al. launch one of their payloads. I was able to track it with good binos for about an hour. The comms died after about 50 mins, probably at 15-18km altitude, somewhere just north of Cambridge.

Some pics and a movie here : http://www.rlproject.com/launch_feb_2008

Fairly ugly press con. just then. There's a medical issue with a crew member - and quite rightly Shannon was giving a firm 'no' to any questions regarding it. For some reason, most of the assembled press ( apart from Bill Harwood, who is always a true professional ) seemed hell bent on asking Shannon to break the law ( patient confidentiality and the hippocratic oath ) time and time again. The timeline has been pushed right a day, and they've going to fill tomorrow with various non-EVA activities.

Doug

Stu and I conducted a highly scientific experiment.

Just as a 1813 ISS pass was happening, I phoned him at work. We watched the pass together. For me, it flew just left of Mars. For Stu, it was just above Betelgeuse, significantly lower. Using carefull science, trigonometric analysis, and accurate measurements - we can thus deduce that the ISS 'really quite high, and rather bright'

The predict was for -2.4 for me, but it flared to what I would estimate is -4 or more about 20-30 degrees above the horizon as it was setting.

Doug

Don't thank me - thank the guys who write the Invision forum software, and thank two racing simulator developers from Southern England for having their forum run using Invision, which made me start liking Invision in the first place

Doug

I saw them the first pass as well. Was it me, or was the Shuttle noticeably faster ( given the lower 'catch up' orbit )

Doug

If you're in the continental US, you should be able to get NTV via about £70's worth of satellite receiving gear (at least, that's what it'd cost here - a 90cm dish and a digital decoder )

Frustratingly, we don't get it over here I wish we could get it bounced over for a subscription.

Doug

That's the thing isn't it. IS it accessible. We don't know that. It's fairly clear that if it is (in terms of navigability AND accessibility of the actual rock under the dust/soil covering) , they'll try to get to it. If not, they'll move on. We really don't want to spend longer or 'use' more rover than is necessary within the crater, as a wheel failure would appear to be not too far away, and with it - a navigational tomb stone.

Doug

I just open http://playlist.yahoo.com/makeplaylist.dll?id=1368570 in Quicktime (with flip4mac on OSX)

Doug