Although hopefully we could find someone to do those other questions.

Actually - on another forum someone suggested that Opportunity start driving north to watch Phoenix land. I responded jokingly that that would be great if only it were in any way possible, feasable etc etc....only to discover he was serious.



Doug

That's the plan

Doug

Shameless plug here for a new Podcast called Living Space - being presented by The Sky at Night co-presenter Dr Chris Lintott and Heart 106.2 radio preseter Hariott Scott.

http://www.livingspaceonline.com/

Alternatively subscribe to this - http://www.audioagain.com/podcast.php?channel=space - in iTunes

Why the sameless plug? I'm in the first episode Also - some Venus Express info as well!

Between this and Planetary Radio I think we're quite lucky!

And please don't kill me if I got anything wrong about the new science at Gusev

Doug

But thinking about afterwards means you have to consider the in-between. Might we wear out the RAT at Victoria - or even have a wheel failure while inside. If we spend 2 months inside - then plan that invokes timelines of a couple of years might make sense. If we spend 2 years inside - then might a further 2 - 3 - 4 year plan be just too much.

Doug

Rob Manning and I swopped emails last night - and we think it might make sense to pool all the questions people have about MSL (and specifically MSL's EDL ) into one thread - and then answer as many as make sense either via a Q'n'A in the style of the previous ones I've done with Steve and Jim - or via Rob's typing fingers.

It'll be a few weeks till we sort this out - but submit-away until then

Doug

I agree on that one - there's years of stuff here at Victoria to study yet.

Doug

We didn't know what the terrain was like from Endurance to Victoria. We had a MOC image which showed this etched terrain - we didn't know what it was like. We didnt know if we were going to get through it. There was nothing else for miles and miles - so there was nothing to be lost by trying. Ignorance was bliss.

Now - we have the information from HiRISE and the ability to compare all the terrain of that huge traverse across Meridiani with surface imagery. We can actually see. There is no supposition involved whatsoever. We KNOW that the dunes around the Purgatory area are hazardous to the MER design. We know that. We can now see dunes that are bigger than that - vast swathes of them - ones that we would struggle to find a route around or through. Thus we KNOW that the terrain South of Victoria is more hazardous than the terrain we crossed to get to Victoria - we can see it - we can see the patterns in HiRISE imagery - and it's the same patterns we saw on the north edge of Erebus - a large dune field that we took a HUGE circumnavigation to get around.

People having been drawing dotted lines on 12m/pixel imagery going south of Victoria. That's meaningless. Yes - Ithaca is a good target. But going South of Victoria isn't. If this vehicle can do another 20-30k - if it can do another 5, 6, 7 years - maybe we'll get to Ithaca...but we sure as hell wont make it if we point SE and gun it. Your human analogy doesn't work - a human could walk it quite easily - these vehicles do not have the abilities of a Human. This wouldn't be hazardous to humans (any more than the act of walking on Mars is going to be inherantly hazardous ) - a human could walk this stuff without thinking.

There was good science at Erebus that we shot straight past - the best exposed festoons we've ever seen. Good science is a good reason. Erebus hasn't been mentioned just for a laugh - it's been mentioned because it was interesting.

This isn't about 'claiming' Opportunity is a priceless asset. It is. Fact. The science team think so, the engineering team think so. I think it would be a waste of that asset to send it into terrain that - given the data we have now - would be a navigation dead end. It's not about avoiding peril - anyone who has been here for the duration knows what Peril means:

http://marsrovers.jpl.nasa.gov/gallery/all...09P1214L0M1.JPG

What's the problem driving over old ground? We're driving over old ground right now - back around Victoria - to get to good science we've already driven past at Duck Bay. Driving back to Erebus would not be that different. Spirit's doing it - back to Home Plate for science, back to Larrys Lookout two years ago. Turning around to re-visit something interesting that you couldn't give your full attention to is not a crime. Pointing at massive dune fields and putting to the foot to the floor is.

Is there not a contradiction in saying that their lifespan is finite - so let's spend 5 years driving South East through dune fields?

Again and again I've said we need more data before making a final decision - fighting and arguing about it now is premature - we're all jumping the gun. Perhaps we can make a solid case for a single HiRISE observation to answer this and submit it to HiROC - see if they'll oblige?

Doug

Got to be over 11km now 10791 at 1177 - a good 200m+ since then.

Doug

The two threads have contracted chronic topic overlap I think we can keep MSL EDL stuff in here, and we can just go "ooo - pretty - nice rendering of Chute deployment - Dan always cheated on that bit!" in the Video thread.

Doug

Doug

You've got to warn people before posting pictures like that


Doug

I think the MSL decent stage will be given the same sort of treatment as the MER backshell and chute....keep away. Although Mastcam might get us a nice shot from 100m away

Doug

The plan as I understand it (and Rob confirmed this) is to let the decent stage fly away uncontrolled and crash itself.

Adding the complexity of making it controlled after getting rid of the payload is un-necessary. You would have to have all the systems that the decent stage uses onboard MSL ( I'm assuming the brains of the operation will be within MSL with a cable up to the decent stage for throttles, a gyro and an accelerometer - I over simplify but that's the basics if I understand it right. ) That chance of the decent stage ending up splatting on top of MSL is probably less than the chance of the first MER bounce recontacting the backshell and chute.

A bad analogy is the MER lander. The rover's WEB was the brains of the whole operation - backshell/lander/etc etc was essentially just dumb - hooked up to the web with relays and so on. Once the final cable was cut - the lander was dead - although to be fair it didn't have big thrusters with a few gallons of hydrazine sloshing about.

A similar discussion's happening in the MSL Video thread.

Doug

To print MOC images like this we have a print that's THIS big

Doug

I actually have "RAD has fired..." from the MERB coverage as my windows startup message. I think that actually breaks the Marsgeekometer.

Doug

Perhaps we could pull off something similar to the 2000 Sols posters I did for the MER team. A photomosaic using all the LORRI images - of the Europa rising image?

Doug

I don't think those advocating it have given HiRISE images a fair viewing. I would love Opportunity to be able to make that trip - but no ammount of poetry or positive thinking will actually make it any easier.

Like I've said again and again - with the data we have in front of us - it's a crazy idea. If we get more HiRISE images that show eagle-to-endurance like terrain for the middle 10km of the tripe....let's do it. If it's all like the part we can see - Erebus-to-Beagle with larger dunes...let's forget about it.

There are places were I see the drive direction images being 180 degrees of this
http://marsrovers.jpl.nasa.gov/gallery/all...OUP2399R2M1.JPG

Experience tells us that you don't go through that. The vehicle can't do it. You've got to go around it - and around it is going to be hundreds of metres across more dunes. Given the data we have now it looks like a 5 year trip that Opportunity could just about make from a navigation perspective. I don't think it's a wise way to spend 5 years when there is every chance of never getting there and having our mobility go up in smoke 6k from anything.

Doug

I think you would end up with a lot of rocket exhaust and high velocity dust impinging on the rover if you did that. The MPL failure was, so they think, a software fault. A line of code would have fixed it - there's little analogous to MSL with the MPL failure really.

And yes - MSL EDL looks crazy. Not as crazy as MPF and MER though.

Doug

We just built three new PC's here at work - Aramis, Athos and Porthos


As for Ustrax's latest map - the first 800m - could be very fast.

The following 3km or so - 400 sols - that sort of time frame - looks very similar to the Erebus-Beagle terrain - but with some areas of much larger dunes.

Doug

I think the plan is the same for both Phoenix and MSL - not DTE tones, but UHF relay to one or both orbiters.

The MOC imagery doesn't tell the story. The nothern rim of Erebus is an area of HUGE dunes. MOC doesn't show that. We need the actual HiRISE imagery to say what we're going to see. Anything else is conjecture.

I don't doubt the scientific value of Ithaca - it would be extraordinary. I simply believe that looking at the HiRISE imagery we DO have - there are some very very large dune fields with very big dunes with no real way around them. The North seems a far less dune-laden area than the south.

This new software isn't magical - it's not traction control - it doesnt mean Opportunity has sprouted wings - it doesn't make the vehicle less prone to digging in its wheels - it simply gives us the means to identify that loss of motion while under power and terminate drives early ( as we saw at Jammerbugt ). The vehicle would still hit dunes, still get stuck - it just wouldn't do so as dramatically as at Purgatory. There is nothing to suggest the journey of 20km from Victoria to Ithaca could be conducted any more swiftly than the 1.5km journey from Erebus to Beagle.

Fairly sweeping phrases about the terrain to the East and South Algo - my crop of the HiRISE imagery of excellent terrain was from due East of Victoria ( where you say it's terrible ). My crop of terrible terrain was from the South where you say there's an easy way out. I'm as sure that Ithaca is a bad idea as you are it's a good idea.

I think there is a very very strong case for getting HiRISE images (even 2x2 binned) of terrain NE, S and SE of Victoria. All this is essentially idle banter without it.

Doug

Posts 7, 19, 20 and 22 in this thread. Maybe you don't intend to, but it comes across as considering heading to Ithaca a plausable, feasable, and something we should do instead of going back to Erebus or elsewhere

Doug

I gotta say - those second two craters look damn interesting - and heading NE you get the feeling from the imagery that we'll be on Endurance terrain rather than Erebus terrain once you're at the Ellipse line heading ENE again.

And Ustrax - that's not the case you've been making - you've been saying Ithaca Ithaca Ithaca Ithaca. Not 'lets go to targets in the East and maybe, eventually, we might get to Ithaca'. Go and look carefully at the bottom of the HiRISE image for Victoria ( the larger one that also includes Endurnace ). It's something of a contrast to big 30k wide HRSC images with dotted lines on them

Doug

Stephen - have you looked at the HiRISE image to the SE of Victoria?

Please do - then come back and tell me you think heading into that is a good idea - come back and say yes, you think Opportunity can cross 20km of mixed terrain including very large sand dunes with no obvious way around them. I'm being serious. Go and look at it - and can you HONESTLY say you think we can get through it with a vehicle with a stuck steering actuator and a history off getting stuck in fairly modest dunes - three times already.

Be bold, be brave, go exploring - I agree. Jump off a metaphorical cliff? No thanks. This is a PRICELESS asset we're talking about. We can spend another two year at Victoria crater doing good science that we can get to. It's here - it's extraordinary - it's feasable. Then - there's stuff we rushed past at Erebus - we KNOW we can get back there. There's exposed rock that is perhaps 2-3-4km to the SW that would be tough to get to - but it could be interesting. Then there's this crater that's half a decade of driving away over terrain we already know to be hazardous to the MER desgn.

I thought Victoria was a brave option - but appropriately so - a 50/50 shot that was worth doing for the science it might offer. There was nothing left to do at Endurance - it was the best option available given the data available. We didn't know that Purgatory was sat there. Given the data available now - were Opportunity sat at the Heatshield - Victoria would still be the best option. Now - sat at Victoria - Ithaca is not a 50/50 shot. I don't even rate it as a 1/99 shot. It's not a case of 'might' get stuck. Opportunity would have a dozen episodes like Jammerbugt. If we had a Spirit like wheel failure - it would be even harder to get out of those sorts of situations.

With the data we have now - with the evidence infront of us - the orbital images of the terrain to the SE of Victoria and comparing it to the terrain we have observed directly - with a knowledge that the driving wheels have a finite life that has already seen one wheel of the twelve on the surface fail - I honestly believe that saying we should drive to Ithaca is nothing short of crazy - idiotic even.

You may well say 'look - look at that great big crater over there'. I say 'look - look at the terrain we would have to try and cross to get there and look at the years of science we can do right here, now" I'm not saying wrap the thing in bubble wrap...I'm saying exercise sensibility - that's all.

Driving to Ithaca would be - given current data - idiocy. It's a romantic notion...but nothing more - I find it increasingly difficult to take people who think it anything more than that seriously because it shows that you're just not looking at the data infront of us and the experiences of the last 3+ years realistically.

10 years from know perhaps I'll be proven wrong as Opportunity drives it's way around the far rim of Ithaca. But now, with the data we have, heading to Ithaca is the wrong thing to do - and gratuitously obviously so.

In short - cut the romantic crap and look at the best data we have and tell me you honestly believe driving to Ithaca is the best use of this priceless asset.

Doug