Mars rover pics

[JHZR2]

Is anyone else as disapointed as I with the mars pics that we have gotten back so far? Frankly, I dont think they are any better, more detailed, or just plain prettier than the pics from the voyager probes that were there in the 1970s.

Youd think that for all the advanced technologies, even so much as the superb digital cams we have these days, they could do a little bit better photography.

Im sure even myself, who knows just enough to take photos that arent a waste of film could take better scenery shots and better photos of rocks than we are seeing from those space probes.

Why is that? Is bandwidth limited in the radio signal from mars to here?

Any ideas or comments?

JMH

Just a quick correction, the Voyager space probes did not fly past Mars. Attached is an example of what is being returned by Spirit. This image has been compressed greatly to get it to fit withing the max image size allowed by this forum software. There is some pretty good stuff coming back from Mars. Much better than previous landers and rovers. Up to now, all the images (not photographs) have been acquired by Spirit while it is still on the lander. Last night (early this morning), Spirit rolled off of the lander and will start acquiring more and better imagery of its environment.

[JHZR2]

Actually I meant viking... My mistake...

My point is, was that pic that much better than the first color pic taken by the viking 1 lander?

[JHZR2]

Or this B&W image

[JHZR2]

Just a point... I suppose in reality I havent seen the hi-res stuff, and probably looking at pics that are shrunk and low resolution doesnt make them much better than the best pics sent in 76...
Is there a place where a common person such as myself can see the full high res pictures, even if they are many MB each? I cant wait to see more about mars.

Thanks,

JMH

We have a site here (JPL). But, I don't know if it is the same URL from home. Let me try tonight when I get home and I'll post the correct URL.

The greatest advantage of Spirit is that it is a rover and will be able to "wander" around the surface "looking" at various things. Also, it has a device that will scrape the exterior surface off of a weathered rock face and do a specral analysis of the underlying, non-weathered rock.

[Lebenz]

I think it’s pretty darned exciting! Given the dust, the rocks with holes and that rocks are pushed up through the surface, doesn’t that pretty much state there was water and ice? Ice pushes rocks through the surface. And dare I say it, on our planet rocks with indentations are usually that way because something was eroding it - either another rock being banged against it due to river currents or countless generations of crustations living on the rock’s surface and wearing holes in it.

[JHZR2]

That is so neat... to be able to essentially dig and show us what its like underneath.

The rover that landed in 1997 has essentially been forgotten (at least I never hear anything of it). Wasnt it supposed to trek a number of miles to some rock formation?

JMH

The Pathfinder (lander) and Sojourner (rover) "ran out of gas". The batteries died. More info at:

http://www.jpl.nasa.gov/missions/past/marspathfinder.html

[JHZR2]

Interesting... Id have thought they'd use some solar cells and batery packs so that it could keep charge. After all, somehow Voyager 1 and 2 have made it for something like 26 years, and still send back data, as they are planning to see what happens as they pass the heliosheath and into the solar winds. But I guess each item is designed with a different task in mind, and different equipment for power generation, etc.

But thats just me, I dont know too much about these things, or why exactly they are designed as they are.

One way or another, it is really neat. I just wish it didnt take so long to get far out in the solar system... More trips there and into the environments of outer planets would be really interesting. I guess they are going to do that on one of Jupiter's moons before too long though.

JMH

The Voyagers and Vikings had/have RTGs (radioisotope thermoelectric generators). Basically . . . miniature nuclear reactors. The political climate today dictates that RTGs not be used due to public safety hazards.

[JHZR2]

wow, interesting... didnt know that.

Do you think that the 'public safety' aspect is all that real when it comes to using power sources like this in spacecraft? I can see if something like Columbia occurs, there could be the potential for fallout, but otherwise it seems like unless it is cost or weight restrictive, which I doubt, it would be a good power source.

JMH

Re: Public safety concerns . . . I try to refrain from political discourse in public forums. It just gets people upset. They say that a person's values are instilled in him or her by the time they are five years old and that they don't change much after that. They may turn away for a time (teenage rebellion stage) but will usually come back in their maturity. So . . . most people have made up their minds, one way or the other. There is little I can say or do to change their outlook. It is good in our system to have differing opinions. That is what makes this country strong. None are right or wrong . . . just different.

[JHZR2]

Well I meant it in more of a scientific aspect... But thats fine.

JMH

[ericnguyen]

Dear JHZR2:

I've read that the resolution of the images received from Spirit is so high that they still can show very sharp and crisp detail when blown up to the size as big as a movie screen! The resolution of images from Viking 1 must absolutely be no match for those from Spirit or Opportunity.

The current highest resolution professional digital (SLR) camera is the Kodak DCS Pro 14n with 14 megapixel resolution (4,536 x 3,024 pixel). I think each of the eight cameras on Spirit may have a resolution as high as 20 megapixels or higher, and may use Wavelet compression (using Discrete Wavelet Transform) instead of regular JPEG compression (using Discrete Cosine Transform). Wavelet compression is used in the newest JPEG2000 specification. I really do not know what compression NASA actually uses for compression of the digital image data from Spirit, even though I feel quite sure that NASA uses Wavelet compression because it's currently the most advanced and superior technique (so much better than DCT used in old JPEG). There is also a compression technique called Fractal Geometry compression, but it is not as mature and efficient as Wavelet compression.

Mr. Volosong please enlighten us more about it.

The Cassini, Galileo, Viking and Voyager spacecraft missions all used Radioisotope Thermoelectric Generators (RTGs) to power its devices and equipments. I remember that around summer 1999, news of Cassini spacecraft being on its way to pass the Earth at a relatively low altitude of about 700 miles caused quite a stir because Cassini (and its attached Huygens probe built by the European Space Agency) carried some RTGs, and there was a probability (quite small) that any slight error in its trajectory calculations or changes in cumulative gravitational force (due to many factors) would make Cassini fall towards the Earth instead of passing it while gaining more "free" speed. If Cassini fell towards the Earth, the atmosphere would burn it and its radiactive nuclear material would be scattered and dispersed over a large area. Fortunately, it passed the Earth without any hiccup and is still continuing along its journey towards Saturn. It will reach Saturn in this mid-summer 2004 and enter an orbit around Saturn; it will then send its Huygens probe to the surface of Titan, one of Saturn's biggest moons, for scientific studies.

All long interplanetary missions (especially to far outer planets like Saturn, Jupiter, Neptune etc...) require nuclear powered generators because the Sun light is extremely weak (due to extremely long distance) for efficient functioning of solar powered panels. These long distance spacecrafts may carry some solar panels but I think they are only there to power some low wattage devices.

NASA has been spending money on a new nuclear power technology called Stirling Radioisotope Generators (SRG). These generators are much more efficient than RTG, and require only as little as 1/4 of the radiactive nuclear material needed by RTG.

Fuel cells and SRG are miracles of science and technology.

Eric