So point where I commit mistakes and confuse something. And no, suggesting things that I never wrote (like cancelling Phoenix mission) don't count.

Not again suggesting things that I never wrote...

Where I wrote about redesigning Phoenix to MSL? I said that I would choose other Scout mission to launch in 2007 (obviously now is too late, but assume that for sake of discussion) and start Phoenix-type mission using polar version of MSL after succes of first MSLs. Instruments would be build from scratch, of course.

Umm - you're busted - I never said that, OP9 did.

However putting your suggesting things that I never wrote to one side for a moment - by suggesting that MSL would be a better thing than Phoenix - by saying that for the price of just 2x Phoenix you could have MSL going there instead, by saying that a rover would be better than Phoenix - by suggesting that MSL could and should be going to the Martian polar regions - you are insinuating in the strongest possible way that Phoenix should not fly...it is the only logical assumption based on your argument, if you think something else, then what is your argument about....but hey...at least I didn't put actual words into your mouth that you never spoke like some around here.



Bottom line :

Phoenix is the best spacecraft - in ATLO or just the drawing board - to investigate the polar regions for several reasons. 1) It has the right instrumentation to answer the questions we need to answer. 2) It has the arm of sufficient size and ability to do the digging required. 3) It is a comparatively cheap lander appropriate for a short life mission that will end with the arrival of the long dark polar winter. 4) The landing site in question does not require mobility as the terrain and science is such that any one spot is good for the science required.

MSL would be totally wasted by sending it to polar regions...it would be an utter disgrace, a waste of time, money, and 18 months of the vehicles life. And yes, I do know that MSL is RTG powered and thus doesn't require sunlight to operate - but the requirement of floodlighting on the vehicle, inability to image long rage, and indeed the fact that it would be slowly frosted over during winter whilst wandering around terrain that's the same as the place it landed and the same as anything it could go and visit.

http://hiroc.lpl.arizona.edu/images/...P_001337_2480/ - THAT requires a cheaper, short life, volatile focused static lander to ground-truth an orbital observation

http://hiroc.lpl.arizona.edu/images/...P_001468_1535/
http://hiroc.lpl.arizona.edu/images/...A_000873_2015/
http://hiroc.lpl.arizona.edu/images/...A_000861_1530/ - THOSE require a highly mobile, geologically equpied long-life rover.

Right tool for the right job.

Doug

Irrelevant. ESA have demonstrated that they can run highly complex missions successfully. It is no more difficult landing a rover on Mars than a stationary lander. So if they decide to do a rover mission, that is there decision.

OK, that just leaves Venus Express, Mars Express, Giotto, Smart-1, Helios 1 & 2 , Ulysseys, and Cassinni-Huygens as just some of th successful deep space missions that ESA and its member countries have successfully achieved. This diverse suite of missions and the depth of aerospace technology that ESA can call out is every reason to think they can achieve a rover mission on Mars. Against this we just have your prejudice that they cannot.

This makes no sense at all. What are you trying to say?

Jon

Some people just don't realise that Phoenix and MSL are two very different missions, designed for very different goals.

MSL is designed for long range, long duration field geology with a secondary astrobiology mission, and is an expansion of what the MERs have done. Phoenix is designed to test very specific hypotheses about soil physics and chemistry. MSL cannot test them, it does not carry the right payload.

Trajectory considerations limit MSL to +/-45 degrees of the equator. MSL would not be able to be sent to the regions that Phoenix can reach (~70-80 degrees N). MSL would be useless through the polar night and would be a wasted mission for much of the time, even if it could be sent to the polar regions

Phoenix will cost US$284 million, MSL of the order of US1.2 billion, more than four times as expensive. For the specific questions that Phoenix is designed to answer, it is the superior probe. There were hopes to test the Viking hypotheses about the nature of the martian regolith hypotheses with MPL, Beagle 2, and Mars 96, so there are a lot of people waiting on this. Plus those who had hoped to see their instruments fly on the 2001 lander.

Phoenix is an excellen mission that will provide some long overdue information on aspects of the Martian surface, will explore hithertoo unvisited regions of Mars, and so so very cheaply.

Jon

I wrote about this already. No any contradiction exists.
If you all did not agree with me, fine. But please, read what I said first.

Because it is mostly already done. I agree that contraption is better that nothing, because now is too late to change anything.

How do you know that's all same? You seem to know very much about Mars. More than NASA. If you can provide reference or cite any scientist that say "all these polar plains are same everywhere, boooring" or something like that...

I seen here (http://hiroc.lpl.arizona.edu/images/...lease_005.html) much more northern plains and they're more diverse that you suggesting. And you can't see underground in these photos.

This is your only revelance of these missions to mars rover mission? That they are soo diverse? I repeat: these missione features no mobile rover. ESA have no experience with missions with mobile rovers. And they have 50% success rate in landing anything on any alien surface for now. And their faliure was on Mars - same place where they want send rover. Not very... assuring.

Tell me why. It is not possible to build polar version of MSL with instruments similiar to Phoenix suite?

Summary:
Phoenix is almost complete, so cancelling it now make no sense, is too late. I hope that this mission will be succesful, because Phoenix is better that nothing in 2007. I critique not concept of mission, but lack of mobility. Your biggest argument is that polar plains are all same. Considering that I hear it from Mars enthusiasts, it is very strange argument.

So, how I would done it? Many years ago, I would pick different mission for 2007, and after 2009 I would go to polar region with MSL modified to withstand polar enviroment and with Phoenix-like payload.

That's all. If you do not like it, well. These are your opinions, like mine.

i was thinking the same thing about phoenix, with the rovers moving all over the place and lasting 1000 days longer than expected… it will be a bit of a buzz kill to see the phoenix land and too us non-scientists, it will seem over and done with comparitively.

however, i am excited to see more northern scenes and get something on the ground in a non-mid latitude area.

__________________
-:–:—: | http://www.wanderingspace.net | :—:–:-

Ah and therein lies the issue. Phoenix, like all planetary probes are designed for science, not just for pretty pictures (though I'll agree it's good for PR). Why spend billions more on an MSL-type mission for scientific goals when we have a perfectly capable landing craft for the job? If there is indeed something that requires further investigation (and that's always the case) then a mission can be properly planned in the future.

__________________
"The bread's hollowed out --- the veggies go on forever --- and --- oh my God! --- it's full of meat!" - Maksutov

And floodlights I presume - to illuminate the terrain in the long dark polar night for months on end - and of course extra heaters to survive through the winter....and er...well...perhaps Connect 4 or something to pass the time during the polar winter when you can see nothing and thus do nothing.

I can not believe you would take MSL away from the terrain for which it is required, and send it to the terrain where it is not - complete and utter madness.

Doug

ESA's overall success rate on deep space missions is higher than NASA, who in the last 20 years have had the failures of Mars Observer, Mars Climatology Orbiter, Genesis, Contour, Mars Polar Lander, and Deep Space 2, and major failures effecting Clementine and Galileo. How much experience Did NASA have of landing on Mars when when Viking was launched? ExoMars is a far lower risk mission than Viking given that many of the unknowns about Martian EDL and the surface have already been solved. By your logic NASA should not have send Viking to Mars until they had sent something much simpler.

Your position might have merit if ESA was just beginning the deep space exploration business, like China and India. However they are not, they have been doing it for more than 20 years. Nor are they neophytes at EDL systems, member countries have been building EDL systems for 40 years. Nor are the technical issues unknown. Thanks to the various successful orbiter and flyby and lander mission it is possible to design precisely for known conditions.

[quote=MaDeR;891096Tell me why. [/QUOTE]

Why can't MSL cope with the polar night?

1) MSL can't reach the poles. A fact you consistently ignore. To make MSL reach the poles you would need either a bigger earth departure stage - not possible with the selected booster - or to shed mass, you would also need to modify the guidance system. Do0 this and it's no longer MSL

2) MSL is not designed to operate at polar temperatures. You would need to redesign the heating system and power system. Do this and it is no longer MSL,

3) MSL has no night driving system. You could provide it with headlights or an image intensifying system, or thermal IR imaging system to navigate. All of which would cost power and mass. Thus either a bigger rover or unloading some of the payload would be required. Wither way it's no longer MSL

Of course it is possible to build a polar rover. There has been at least one study, for a MER-like rover designed, like Pheonix, to last for the Martian summer. But for reasons already explained, it is not possible to put a MSL lander into the polar regions. It would be a completely new rover.

Why would you want to put the Phoenix instruments onto MSL? They are optimised for a stationary mission, MSL's instruments are optomised for a mobile mission. Why MSL instruments would you leave off for the Phoenix instruments?

Because the science questions that Phoenix is designed to anwer about the physics and chemistry of the Martian surface do not need mobility. Some background is obviously neccessary.

The Viking astrobiology experiments discovered that these areas had identicial peculiar surface properties indicating gasesous exchange with the atmosphere, nutrient binding and oxidation. These were superficially suggestive of biology, but the detailed reaction patterns and the absence of detectable organics meant that the most likelyc ause was unusual surface chemistry involving the presence of reactive clays and super oxides and peroxides.

This was done at two widely separated localities with identical results. Combined with data from other missions, most significantly Phobos 2 that the surface dust has the same composition globally (confirmed by later missions), the evidence is that these properties occur right across Mars.

These conclusions are dominated our understanding of Martian surface chemistry and physics for 30 years and are long overdue for testing. There have been four previous attempts to test them, all unsuccessful - MPL and Beagle 2 crashed, Mars 96 did not leave LEO and the NASA 2001 lander was cancelled. A detailed physiochemical understanding of what causes the chemical activity of the martian surface will have major implications for instrument slection of future astrobiology missions, how we understand glocal interactions between the atmosphere and the surface, the possibility of present life on Mars, whether Mars could ever have supported life, the liklihood of terrestrial organisms streading on the surface, and what sort of materials should be selected for future probes.

Because the suspected properties are globally distributed they need only need to tested in one spot. Since the northern high latitudes of Mars are attractive for many reasons - the presence of near surface water ice, the existance of pressures, temperatures, and humidities high enough on occasion to sustain liquid water - by sending the probe there would kill two birds with one relatively cheap stone.

So they only need in situ measurements in one locality to test these hypotheses. What is it about this that you fail to understand?

We all have wish lists for how things should have happened. Mine would not have a 20 year hiatus in US unmanned exploration and a continuation of Soviet missions from 1974. Even better the US would have maintained the peak imputus of the Apollo pogram and have had people on mars in the mid 80's. But this is all wishful thinking as none of this happened. In the fiscally constrained reality we live in Phoenix will still, God willing, deliver us very usefu, indeed essential science, long over due, for almost a third the price of the MER mission and less than a quarter that of MSL.

Of course this is all our opinion. But it is preferable that opinion be informed. In your case I would hope you would constrain yours by a somewhat better understanding of relaities, be they the capabilities of ESA, how goals of different space missions effects their design, and the resulting operational constraints. After all, that is why people copme here, I hope, to learn from each other.

Jon

I repeat again: I'm interested in missions involving mobile rover, not any "soo wonderfully diverse deep space" missions. Tell me, how many these mobile rover missions NASA preformed, and how many these mobile rover missions ESA preformed?

This is rubbish. These missions was highly succesful, in spite of all faliures. Especially Galileo.

ESA IS novice in planetary surface exploration business. I already told that I don't care with experience in deep space - I agree that ESA can deliver their ExoMars to Mars. But landing and surviving on alien surface is completely different story.

This is not important, how it is named. Most important question is different: are changes feasible? I think that you would answer "no".

Maybe. Unfoturnately. If "polar version" of MSL (with minior changes only) is not possible, my proposition is not possible.

This answers your question?

I do not understant that you're so sure about "one locality". I would not be surprised if after Phoenix scientists will propose another mission to pole, but with mobile rover.

Err - Huygens?

Look - it's very simple. There is orbital evidence for hydrogen in polar regions. We need a ground truth to find out what form it is. The cheapest and quickest way to do that is to send a comparatively cheap lander up there to have a dig around. That's what we're doing.

http://marsoweb.nas.nasa.gov/landing...r_Guide_v2.pdf

"As the latitude increases (north or south), several conditions begin to develop that will naturally reduce rover operational efficiency. When the latitude approaches 50-60°N or S, these can in some cases be significant. For example, reduced illumination and the presence of CO2 frost may degrade the quality and interpretability of images used for science or rover operations, such as arm motions or driving. Persistent cold temperatures may reduce the energy available to operate the science instruments. Finally, the short duration or absence of Earth view will impede direct to/from Earth communications."

MSL design can do +/- 60 degrees latitude. You couldn't take MSL to the polar regions without a dramatic redesign, without a bigger more expensive LV, without different thermal design, without a means to opperate for many months in total darkness. It wouldn't be MSL any more. It would be complete redesign, perhaps using the MSL landing system of a decent stage and the Skycrane manouver.

What you're basically saying is "wouldn't it be nice to send a rover to the north pole of Mars"

Yes - it would - it's be great to send 50 MSL's to all over Mars...but that sort of money isn't around - Phoenix will answer the first level questions we want answering for the least money, and the abilites of a rover are far far better sent to the layered outcrops that the 40 or so landing site proposals are all about. Given our current understand of Mars, and the observations taken by MGS, MEX, MRO and MODY, a cheaper static lander to the poles and a mobile vehicle to equatorial layered outcrops is the best next step.

Yes, that was a success. Unfoturnately, ESA still have 50% faliure rate involving landing on anything. And that faliure was on Mars, not Titan. So better they be prepared.

Yes.

You're convincing, but... what later? When you would send any rover (MSL or no MSL, not important) to polar regions?

Actually, Beagle 2 was not an ESA project, it was classified on an instrument on an ESA spacecraft - ESA's involvement was minimal and indeed that is one of the main recommendations from the B2 accident investigation documentation - that ESA's involvement should have been more extensive throughout development.


I don't know - it depends what Phoenix tells us. I can't imagine the polar regions justifying a rover ( fundamental reasons, the long polar nights of several months, and little change in terrain over rover scale - 5-50km - distances ) in the near future if ever - even the Phoenix PI admits "After all, this may be the last mission to the exciting polar region for a long time."

I would put a dozen of the MSL proposed landing sites higher up a list of "scientifically justifiable" for an MSL type vehicle before the polar regions - both from a position of scientific justification, and operational limitations...you only get six months before the dark comes - better to spend another 150kg on instruments to work the hell out of the reachable terrain, than 150kg putting wheels on the thing to do half a job on a dozen km of similar terrain

When you look at the HiRISE images of the Phoenix sites - you look at them....then look at one side, compare it to the other side...there would be no new science to be gained by traversing that. Looks at Gale crater - there would be new scince in moving 1 metre up the outcrop - same at a lot of Meridiani sites, and other sites. These are sites that REQUIRE mobility to do the best science - that is where the money should be spent on wheels.

I would rather send a static deep drill than a rover to either pole in actual fact - that would be the next interesting spacecraft in the MSL mass-scale vehicle ( 750kg on the ground ). Land anywhere within a 20km diameter circular landing site - take the remote drilling and analysis hardware that's been on the drawing board for a few years - and do the science with mobility in the vertical, not the horizontal...particularly given that where we see the layers from orbit - we're seing these layers both contaminated by current martian environmental conditions AND often on steep slopes that a rover could not navigate. Better to go 'high' and drill down through those layers ( and oh wow - the science from that would be amazing! - Martain climate records!)

In terms of a bigger picture - I don't think were at a point where we are able to send the mass of a payload that would justify mobility (a deep drill type instrument ) AND the means to move it a scientifically significant ( hundreds of km ) distance within one landing. I'd still pick something like a static deep drill over an MSL type vehicle as the next polar mission - simply from a 'best science per $' perspective.

Doug

Oh, now we renunciate ESA involvement, eh? Well, success have many fathers, faliure no one. Not very convincing...

Mistake of ESA. On their head will be it.

Yep, deep drill MUST be immobile. But I think that first kind of this drill will be preformed with human assistance. Looooooooooong time to wait, even if NASA own wet dream of sending humans to Mars fulfill at period mentioned in Bush Vision (chances like snowball in hell