ExoMars Options

[Guest_Sunspot_*]

http://news.bbc.co.uk/1/hi/sci/tech/4180840.stm

Europe has fixed on a concept for its next mission to land on the Red Planet.

It aims to send a single robot rover to the Martian surface along with another, stationary, science package.

[djellison]

To be fair - it was hardly a beautiful tarmac highway....

http://www.darpa.mil/grandchallenge05/gran...05/dsc_3925.jpg

There are bits of the floor of Gusev crater, and almost all of Meridiani where I would rather drive my car than on that road

Doug

[mcaplinger]

To be fair - it was hardly a beautiful tarmac highway....

Most of the teams preprogrammed the entire route from airphotos/satellite images and could have (or did) dead-reckoned nearly the whole way on GPS without even having vision or laser-scanning systems. And the vision systems were highly optimized to find the road edges.

I looked at this fairly extensively a few months back, and in my opinion the applicability to planetary rovers is pretty low. I won't even discuss the relative power density between gasoline and solar or RTG systems. Between lidar and racks of processors, the GC vehicles were burning through kilowatts of electricity.

[Guest_DonPMitchell_*]

Most of the teams preprogrammed the entire route from airphotos/satellite images and could have (or did) dead-reckoned nearly the whole way on GPS without even having vision or laser-scanning systems. And the vision systems were highly optimized to find the road edges.

That's what I was getting at. It is a successful but special-purpose solution. I do think it is feasible to get a rover to avoid obsticles with occasional calls for help. But that takes another special-purpose solution that is pushing the state of the art. The rover is not going to be "smart" in any sense.

News articles about these kinds of things always exagerate, both because the journalists don't understand the science and because the academic culture has evolved to speak very aggressively and compete for precious small grant money. There is a natural tendancy to anthropormorphize, and you see blatent attempts to encourage that with projects like these. They are fun to check out, but what you see is misleading.

What biological brains do is indeed remarkable, and the robots you see in movies are pure science fiction. Nobody really knows how smart a computer could be if it was programmed correctly. Maybe a high-end PC could be as smart as a human, but the breakthrough in software technology has not happened yet.

[Stephen]

That's what I was getting at. It is a successful but special-purpose solution. I do think it is feasible to get a rover to avoid obsticles with occasional calls for help. But that takes another special-purpose solution that is pushing the state of the art. The rover is not going to be "smart" in any sense.

Actually, the issue here is navigation. Avoiding obstacles is only a very tiny part of that.

In that respect Meridani and Gusev are not really very challenging sites and Spirit and Opportunity not really very representative of the kinds of rovers that will be needed to traverse them. Both sites are largely open plains where for the most part obstacles are few and far between and those which do occur a rover can generally (the sandtraps Opportunity keeps getting itself mired in are an important exception) see coming for dozens of yards if not a mile or two off, and thus can identify them (and work out a way around them) long before it actually encounters and has to deal with them. Even the dune/ripple fields Opportunity is currently traversing are no real obstacle. Not only can it see over their tops, when it comes to an end of a trough instead backtracking and going around to another it generally simply rolls over a ripple to a neighbouring trough. That sort of solution would have been far less viable, if not downright impossible, had it been confronted by (say) the kind of rock-filled obstacle course Sojourner faced at its site.

As for the rovers themselves, the task of navigating Spirit and Opportunity is done almost entirely by minds back on Earth. For example, Opportunity does not decide for itself which sand trough to travel down. Its human babysitters decide for it. In that respect nothing much has really changed since the days of the Soviet lunar rovers of the 1970s and it seems unlikely to change any time soon; and even if it could change it needs to be remembered that a rover is really only a kind of proxy explorer for its human controllers on Earth. The latter will want to decide for themselves where their proxy is going. That inevitably is going to slow rover progress down to the speed the humans can get pics and other information back from the rover to Earth, make a decision, then upload the next batch of instructions. Not to mention limiting it to how far the humans can see.

What biological brains do is indeed remarkable, and the robots you see in movies are pure science fiction. Nobody really knows how smart a computer could be if it was programmed correctly. Maybe a high-end PC could be as smart as a human, but the breakthrough in software technology has not happened yet.

No existing PC, high-end or otherwise, would be able to run such software--because no PC yet invented can match the speed of the human brain. Individually, neurons are certainly slow-coaches compared to even the slowest electronic CPU, but when they are harnessed in parallel, as the human brain does, they can process information at blinding speeds. You have only to consider how fast your own brain can identify obstacles in front of you and get you to react in some appropriate fashion then compare it to the time it takes Spirit or Opportunity to decide that the rock in front of them is an obstacle they have to go round rather than over.

Hardware breakthroughs as well as software ones will be needed before electronic brains became as smart as human ones. (And even then do not expect to see them being placed inside rovers and rocketed off on one-way trips to Mars. The creation of AI's is going to pose all kinds of ethical dilemmas when they do eventuate. For if computers ever do become as smart as human beings one issue that is inevitably going to be raised at some point is whether they should be accorded the same rights as human beings. That would presumably include not being sent off to other planets on what would amount to suicide missions.)

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Stephen

[djellison]

n that respect nothing much has really changed since the days of the Soviet lunar rovers of the 1970s and it seems unlikely to change any time soon; and even if it could change it needs to be remembered that a rover is really only a kind of proxy explorer for its human controllers on Earth.

Actually - that's not quite fair - Sojourner and MER were both able to be given a target point, and make progress toward that target point, and would avoid obsticles in the way, navigate around them and return to the target point. There was one great example where Spirit actually gave up and drove backwards around an obsticle early on.

So yes - you couldn't say to Spirit "go to the top of Husband Hill " from the rim of Bonneville..it still requires people in the loop on a daily basis - BUT - it's a lot smarter than you give credit for really.

Doug