Tuesday, October 8, 2002 Open in New Window
Joseph Kolecki: Good afternoon, everybody, or whatever time of day you might happen to be in, good evening, or good morning. My name is Joe Kolecki, and I'm broadcasting to you this afternoon our time locally from the Glenn Research Center in Cleveland, Ohio, the United States. The Glenn Research Center is one of 13 or 14 major facilities that are associated with NASA, which is the national aeronautics and space administration. This is an independent branch of the U.S. federal government, which has the twin mandates of doing working technology and science developments in aeronautics -- that is, flight in the atmosphere -- and space, flight and exploration beyond the atmosphere including the moon and planets of the solar system.
I'm going to talk to you today from my experience with the Pathfinder mission. I was one of six scientists from the Glenn Research Center that was made a part of the Pathfinder mission. We were given the role of doing some technology experiments on the rover. My particular work I identified an actual issue that might be associated with traverse on the planet Mars, specifically electrostatic charching of the Martian surface material. That was based on a good deal of practical and theoretical studies which I guess I should outline at least in brief. When we sent astronauts to the moon in the sixties and seventies, of course they got very dirty. They became dust-coated. And it was pretty clear that one of the mechanisms that caused the dust to adhere to space suits was electrostatic charging. One of the stranger episodes in Apollo that actually has not been written about too much is the stories that are told by the individual that stayed behind in the command module. Now, you know the way Apollo worked, there was an orbiter that stayed around the moon, a command module, and then there was a lander that went to the moon, and they carried all but one member of the crew. That one member stayed up in the command module, stayed in permanent orbit, stayed in touch with the people on the surface and, of course, relayed information back and forth between the moon and the earth.
The observations by the command pilot involved coming around from the night side of the moon, across the morning terminator. The terminator is the line between night and day. So the morning terminator on the moon would be the line where, if you were standing on the moon, you would be seeing the sun rise. And the command module pilot quite often reported that he saw what appeared to be thin clouds high above the lunar atmosphere, tens of kilometers -- or the lunar surface, tens of kilometers above the lunar surface.
Now, the moon has no atmosphere, the moon has no water that we are aware of, so clouds on the moon make very little sense. And, of course, these individuals were asked to check their observations very carefully. They did attempt photographs, and I'm not sure if any of the photographs really showed anything, but it was finally concluded that what was happening is that as the sun rose and light came from -- onto the dark lunar surface, which was very, very cold, ultraviolet photons from the sun caused electrons to be injected from the cold dust leaving behind positively charged dust and the dust was literally levitated on electric fields to altitudes of tens of kilometers above the lunar surface.
Now, this phenomenon has really not been studied to any great extent on the moon, and therefor, of course, hasn't been written about, other than to be included in footnotes and introductions and reports on other subjects. I first heard about this probably in the 1980's, and I thought it a curiosity at best, but shortly afterward began working with the planet Mars. And it immediately struck me: Could there be a similar phenomenology on Mars. I started doing research and talking to people and found out there were maybe half a dozen people in the United States that had thought about electrical activity at the Martian surface but that no one had really done anything about it.
So I decided, well, maybe this was a piece that would be appropriate to the group that I was with at the Glenn Research Center, and we went for funding, we got it, and we began some studies to look at the Martian surface. We did some theoretical studies, we did some laboratory experiments, and maybe most important of all we held a workshop where we had something like 25 or 28 experts on the moon, earth, and Mars and space exploration come together for three days here at the Center and just talk. And when we were finished with that workshop, we had a very extensive list of potential charging and also surface chemical phenomenon that one might expect tone counter, not only at the surface of Mars but in its atmosphere and even in Martian orbit. We put this together into a paper and summarily be published it and interested the space community somewhat in the studies that we had done.
At a later point in time, I was approached by the Pathfinder community with the question that asked essentially, "Look we are going to roll this little rover out onto the Martian surface, and we're going to traverse across the Martian duracrust." The duracrust on Mars is the actual surface locally. The dust is cemented locally to about a few millimeters, a few centimeters' depth. It's thought by water that sublimates from ice that's pretty deep below the surface migrates toward the surface, condenses very briefly at the surface, melting cementum -- that is clay-like material -- and very loosely binding the Martian sand together. Martian sand grains are maybe on the order of tens to hundredths of microns in size.
The duracrust might be comparable. Those of you that live in snow areas to the crust that forms on those very, very cold winter days where the powdery snow was underneath but there's a crust on the top and sometimes if you're light enough you can even walk on that crust, it will support your weight. The Martian
duracrust is not that thick or strong, but it is certainly analogous. Well, I answered in the affirmative that certainly one could expect there to be some level of electrostatic charging, whether or not it would be a hazard to the rover was unknown so we began by make some mathematical model and see we continued in the laboratory and showed, sure enough, that charging occurred to a very large extent, much larger than we had expected, under simulated Martian conditions. We narrated this information to the engineers at the Jet Propulsion Laboratory who were designing the rover, and who were putting the mission together. And it was determined that we should become a part of the mission, and so we did, initially in a consultation capacity, and later in, actually, a (unintelligible) capacity where we mounted some mitigating devices, charge mitigating devices on the rover.
That's my background, and that's why I'm in front of you today. And I'll probably be talking a lot more about Mars and the conditions on Mars than I will about actually robotics, although I will be saying a substantial amount about the Pathfinder Rover as a robotic tool.
The type of information that I'm giving you will be linked with information that you're going to receive later on by other speakers, who will speak more about the device itself.
In designing a robotic device, a lander, perhaps, or a rover to go into a remote region, one has to understand the characteristics of that region -- in other words, have a map of the environment -- one has to have a good sense of the type of machine and its function, and then one needs another piece to go in between we call environmental interactions. Components in the environment will act, or interact, with components in the machine, and vice versa. The environment will alter the machine, affect its behavior. The machine will alter the environment and affect it's behavior. It's that link that was of most interest to the group that I am with here at the Glenn Research Center. We are very much involved with spacecraft environment interactions, and this was an opportunity to extend some of our work to the surface of Mars. Now, I'd like to go to the PowerPoint slides. If you would all go to the cover slide, that is the very first slide, you should see a light blue background with a picture of the sun, and two orbits, the Earth and Mars, and the title, "Exploring Mars, Pathfinder Rover electrostatic charging," and in the lower right-hand corner, "October 8th, 2002," and my name, Joseph Kolecki. That cover slide should also include the name of Ruth Peterson who is with me today and who is a consultant and editor on all of my work, and evidently it was left off when the slides were edited locally by the institution that's putting on this course.
Now, if we could advance to the next chart, the chart is entitled, "Preliminary activities," and these activities are simply the questions, the multi-choice questions that were presented to you or made available to you on the Web. The first question is, what surface conditions prevail on Mars? The answer to the question is letter A, Mars surface is cold, it is dry, and it is dusty.
The second question, "How might the surface conditions on Mars be related to ambient electrical activity?" The answer here again is letter A, "Conducive." The other response, "not conducive," certainly is false. "A little conducive is an understatement," and "conditionally conducive" may be proven true in the future. We certainly don't have enough knowledge yet about electrical phenomena on the surface of Mars to understand how it varies with local conditions. So the answer at the moment is "conducive."
Now, let's go on to the next page. The third question, "What surface element on Mars would you think most likely to develop and carry charge?" And here, the real key answer toing this question is the word "carry." Of the four possibilities, only one is capable of any kind of extended motion. Rocks, by and large, are static energy. So is the duracrust, and so is the volcanic glass. The dust, however, is extremely mobile and can be carried by even the thin atmospheric winds that we know to occur on Mars.
So the answer to question 3 is letter B, "dust."
The fourth question, "What charging mechanisms do you believe are operational on Mars?" This is one of the same questions that was posed at the workshop to the attendants and we didn't know what mechanisms to think about, so we said, "From your experience, what do you think would happen?" This is the best sometimes a scientist can do. The options, collisional charging, triboelectric or frictional charging, and here we mean grains rubbing against brains or colliding with brains, the photoelectric effect, or none of the above? The answer is A, B, and C, all three are to be expected on Mars, and, in fact, there's pretty good evidence that at least two of those occur extensively on Mars.
Can we go to the next page.
The fifth and final question, "What are some of the issues associated with vehicle and astronaut charging?" The answers here are letters C and D. Charge could certainly impact operations. If a spacecraft acquired a differential charge -- in other words, some surfaces are highly charged, others are not highly charged,
and develop voltage drops due to these, these drops could have effects on electric currents say in the electronics that run or govern the machine. A discharge might be mistaken by an onboard computer as command when no command was issued. This would be an impact to the operation, it could result in anything from a minor malfunction to a serious loss of equipment.
Charge could also produce failings conditions. And here we're looking somewhere within the next half century or so (fatal) to that time when we believe human beings will actually travel to Mars. If humans are migrating about, walking about on the Martian surface, and they require a differential charge, and then subsequently come in contact, two hands, perhaps, come in contact, an electric discharge could blow a hole in a space suit glove. If there is no mechanism to stop the air leak, that condition could produce great harm to the astronaut. It could in an extreme condition even result in death snaught. So it's important for us to understand electrical conditions on the surface of Mars so that we can design robotic machinery, and we can also design life support devices from space suits to rovers to a habitat that will provide a safe environment for astronauts and a safe operating environment for machines.
Let's go to the next chart. This is a chart entitled, "Simple facts about Mars." Mars, as you know, is a red planet. The red or the auburn color is actually due to the presence of large amounts of iron rust on the surface. There is no free oxygen on Mars because there are no plants to maintain an oxygenated atmosphere. An oxygenated atmosphere is by and large an unstable atmosphere. Oxygen either escapes or it combines in some way and locks itself up chemicalically with other materials. In the case of Mars, it is replete with automatics ides, peroxides, super oxides, when things that are unknown on earth. Mars is roughly half the physical size of earth. It has a day that is approximately 37 minutes longer than a terrestrial day. Its axis is tilted at about 23 degrees, similar to the earth, so the northern and summer hemispheres experience complementary or dual seasons, summer in the north, winter in the south, and so on. The Martian year is about twice an earth year. The mass of Mars is roughly 11% that of earth. The gravitation at the surface is roughly one-third of a terrestrial G. The Martian atmosphere is a very thin mix of tremendous dominantly carbon dioxide with other elements. It shows here 3% nitrogen, but there are fractional percents of water, some of the argon-krypton gases of that type and so on. Essentially no free oxygen at all.
The average temperature on Mars is somewhere between minus 140 to negative 20 Celsius. The 20 is a misprint. Please put a minus sign in front of that. Mars is cold, and its surface in general seldom, if ever, gets above the freezing point of water.
Let's go to the next chart. This is a very busy chart, showing Mars and showing some of the surface features on Mars. We identify at the top the north polar cap. Now, Mars indeed does have ice or frozen material at both the northern and southern pole. The North Pole is much more extensive in expanse than the South Pole, which looks like a little button in the telescope. The North Pole shows evidence of having expanded and contracted many times over the long history of Mars. That's evidenced by terracing in the land forms that surround the pole.
We have currently discovered large amounts of water ice around both poles with dust suspended in the ice, a relatively new discovery made by NASA's Mars Global Surveyor, which is currently in orbit around Mars and totally revolutionizing our picture of the red planet.
We see also the northern desert, which is again that rust-colored surface. It's largely loose sand, volcanic glass, and other kinds of materials. We also see darker features which represent a much older surface, possibly comparable to the mantle of the earth. Now, those of you that know geology know that there are only a few places on the entire surface of the earth where mantle rock is believed to be exposed, and those are in the very deepest abyssal trenches at the bottoms of the oceans, very near some of the extensive fault lines.
There are no regions on the earth's surface that we are aware of where mantle rock can be obtained without digging very deeply, but on Mars, there is a substantial difference in altitude between the darker and lighter areas, and it is believed that the mantle, if you will, of Mars is extensively exposed in these older areas. Why this should be so, as far as I know, is not clear.
We see the Tarsus region, which we're going to take another brief look at, which is a planetary bulge, testifying to a very cataclysmic prehistory, if you will, of Mars. We see mount Olympus, which is one of the great volcanoes on Mars, the Mariner's Valley, which is the Martian Grand Canyon, larger in width than the United States is from coast to coast, and we see some evidence of water in the form of cirrus clouds. These clouds can actually be imaged from earth using the Hubble space telescope.
The next chart, if you will, shows a crescent Mars, and the chart is entitled, "Tarsus," T-a-r-s-u-s. This crescent Mars shows a large belly in the center of the crescent. The crescent should be like a simatar or like a bow, but in fact it is very different from a bow. When these images were first acquired from the spacecraft, I believe the Mariner spacecraft, it was immediately observed that Mars, among other things, was badly out of round. There's a long story, there's a long history that goes with that that I'm not going to go into, but that we have challenged other students, foreign students overseas, British and Japanese students who have actually done some considerable work with us theorizing and studying this particular region.
This is Mount Olympus, which we're seeing it near the top, roughly about the same size as the state of Arizona and get a map and look at this state and imagine what this mountain would look like if it were a feature in the U.S. This mountain is between three or four times the height of Mt. Everest, which is the highest mountain on earth.
Here again the Mariner's Valley, and to the extreme left of the screen where you see the two dark blemishes on Mars, those are two of the volcanoes that attend Olympus Mans. This goal gas crosses the Martian surface, and it is well in excess of 3,000 miles from end to end so that one could place the U.S. coast to coast easily within the left and right boundaries of this region.
Mars had a past that was very similar to earth. These are arroyos, testifying to the presence of liquid water on Mars at one time. That presence of liquid water suggests a denser atmosphere, a warmer surface, and even possibly a hydrological cycle, which included the development of clouds, possibly funnel systems, cyclonic storms, and certainly local and regional rain.
Another water feature, hydrological feet -- this is extremely ancient. One can tell that because the outlet, the shoreline, the inflow channels and so on are well eroded and there's a lot of cratering over top of it. The cratering would have happened much later on in the formation of the surface, but very definitely geologists have identified the presence of a dry lake bed here on Mars, again showing that there were extensive amounts of liquid water on the surface of Mars.
Was Mars alive at one time? Is Mars alive today? These are some of the most tantalizing questions that we can imagine. These pieces -- what we're looking at, actually, is an electron micrograph of a part of a rock that we believe comes from Mars. When I showed you Tarsus, I talked about cataclysmic events, impact events, essentially, that would have thrown material free of the planet. Some of this material has gotten to earth, we believe. This is one of about 13 rocks that were mined out of our own south polar ice cap. And in this rock in 1996, using advanced electron microscopy, these images were developed, and they look for all the world physically and chemically like the same type of nano-bacteria we find in the earliest pre-Cambrian rocks on earth. Whether these are really fossils of organisms or something else has not yet been determined, and that's a problem for the future that maybe some of you will become involved in working on.
Why do we go to Mars, and why are we interested in Mars? Why do all this study? By the way,we're on the next chart. Well, Mars is the most Earth-like planet. Venus has been called a sister planet to Earth, but it's in the throes of a runaway greenhouse. It is largely unapproachable by spacecraft because of the extremely high temperatures that prevail at the surface. Mars, on the other hand, doesn't present that problem. It's an approachable planet, it's a planet one can land on. It at least it had a terrestrial life past as you could guess from some of the pictures I've already showed you. We have the technology to get there today, to land there today, and we certainly have the hope of visiting Mars with expeditions and then possibly going toward future colonization. I put three dots because there are probably a lot of reasons that all of you could think of, and I would challenge you to think about reasons why we would go to Mars, why perhaps you would be interested in going to Mars.
My last reason really is what drives persons like me to be a scientist, simple curiosity. It's there. It's there and it's within reach, so why not? Why not go take a look?
Next slide, "Why sent robots to Mars?" Well, for the present, robots are more durable, certainly, and less expensive than humans. If we put a robot into a long-term orbit to eventually get it to Mars and the sun goes through a flare event, we don't have to worry about radiation from the sun killing anybody, that's a big plus to having a robot. The robot is essentially immune to these sorts of things. Humans, we have to take extensive care to keep them healthy and alive during a mission, particularly during the traverse from the Earth to Mars.
Robots, it has been proven, can accomplish almost as much as humans. Robots can help us to learn a great deal about Mars, as much as we can about the Mars environment, before we send humans.
This last point is important because the Martian environment is very, very different from the terrestrial environment. Earth's environment can be lethal to people in many ways. One can drown in the ocean, one can fall into a volcanic vent, one can climb too high on a mountain and become asphyxiated, one can stand outside and be struck by lightning. Mars also poses hazards, but the hazards are of a different type in a different quantity than on Earth, and before we go there, and before we can design for good, safe operations and has beentations, we need to learn about the environment. Robots are one of the ideal means of doing this.
Now, "robot," the word itself comes from a Czech word, robota, which translates into English as "compulsory labor," compulsory labor. The robot is essentially a worker, compelled by its operators to accomplish certain tasks. Our Pathfinder Rover was semi-programmed, at least, to perform certain operations on the Martian surface. The remainder of the programming was done in real-time from Earth itself as the rover moved across the surface and sent back information.
The next chart shows some of the environmental issues that we were concerned about at the Martian surface. Certainly there is a radiation environment. A crew living on Mars will be directly exposed to solar ultraviolet, solar high energy particle radiation, galactic cosmic rays and so on. On Earth we are shielded from these things by a magnetic field, and by a good, dense atmosphere. There is an unstable surface chemistry on Mars. I spoke of super-oxides and super-peroxides and things of that sort. It turns out that these things are so unstable that the simple expedient of spilling water on the surface could liberate large amounts of gas, particularly molecular oxygen which burns very readily. In the case of generating such an oxygen cloud, an electric discharge could set off a fire or set off an explosion. The fire wouldn't last very long but it might last long enough to do considerable damage, particularly if humans are anywhere in the vicinity.
The last surface issue is biology. I put a question mark there because we don't know what the biology would consist of if it consists of anything at all. But we are looking at a planet that gives us more and more hope for not only prehistoric biology, but extant present-day biology, and it's not entirely improbable that the first living organisms on Mars, if there are living organisms on Mars, will be discovered and cataloged by sophisticated robotic rovers with drills and with onboard laboratories and instruments to do the proper analyses.
You know, the Viking landers carried such instruments, but what they identified was the unstable surface chemistry, not life on Mars. Now I'd like to talk just a little bit about electrical charging in the Martian environment. This was my particular concern with Mars when I became involved with the Pathfinder mission. All right, we should have gone through a couple more charts. I am currently on a chart that is titled, "Why expect charging on Mars?" Again, "Why expect charging on Mars?" And then there are four lines or so of print underneath it, there are four causal mechanisms.
The first is that Mars is a cold, dry climate. And again, this is an answer to one of the questions that I had given to you prior to our meeting today. If you think about cold, dry climates, they're very good for charging things up. Those of you that live in climates and experience cold, dry winter days are probably are probably familiar with the simple hazard of walking across a carpet, acquiring an electric charge, touching a doorknob, and getting a zap. Mars could look a lot the same way. An astronaut moving across the dry Martian sand could acquire a voltage of several thousand volts and in reaching for another object that isn't charged, discharge through the atmosphere. The discharge might be harmless; the discharge might not be harmless. The magnitude and the nature of that discharge is one of the things we have yet to learn about.
There are seasonal winds on Mars. In fact, Mars is noted for seasonal dust storms that are planet enshrouding. In other words, a storm that begins typically in the southern hemisphere at springtime that fills up the southern hemisphere spills over and covers the northern and southern hemispheres together, lasting for better than six to eight months.
There are local dust storms; there are local dust devils; there are daily breezes to and from the morning and evening termnators. So we're apt to stir things up. And I spoke of triboelectric charging. Dust screens colliding in the Martian atmosphere could produce atmospheric electricity. I spoke already of the dust storms. I spoke already of the dust storms and of the dust devils. Okay, let's go on.
The next charge -- or the next chart is entitled, "What physical mechanisms might be involved?" Well, again, I list four physical -- or three physical mechanisms. One of them is collisional motion, or collisional charging, due to turbulent motion in dust clouds, in dust storms. The second, and we've talked about this already, is triboelectric charging, frictional charging, which is due to a wheel, say, moving or grinding across the Martian surface, or an astronaut snuffling across in a space suit with some sort of boots.
The third mechanism is photoelectric charging, and this would be primarily due to ultraviolet light from the sun. This, again, is a response to one of the questions, one of the multi-choice questions or multiple-choice questions that you had prior to this particular conference.
The next chart shows two dust screens in motion. We're going to talk for a moment about collisional dust charge exchange. This is one of the more interesting mechanisms that we've identified on Mars. I've deliberately shown two grains of different size. It turns out we learn something very astonishing when we ran a simulated robot in a Martian environment that we built here on Earth. We had a vacuum chamber that we filled up with ground volcanic material to simulate the Martian dust. That filled with a mix of gases to simulate the Martian environment, and we discovered through a whole series of experiments that when the material charged, the smaller grains tended to charge positively, the larger grains tended to charge negatively. And no one expected that this should occur. When we found it, my first reaction was to say, "That's exactly like thunderstorm charging -- water droplets in a thunderstorm charge the same way." When there's a collision in a thundercloud, a little droplet will tend to lose an electron to the larger droplet. The little droplets are lifted aloft; the larger droplets tend to move down, producing a negative cloud base in a positive cloud top, which an electric field, which, if it becomes intense nutch, results in a lightning bolt within the cloud. The negative cloud base produces an image charge on the surface, which is again positive, and produces another set of conditions for cloud to ground or ground to cloud lightning.
Well, when we made this discovery, I realized that what we had in hand maybe for the first time ever was an actual mechanism for electricity or electrical action as a result of Martian weather, and this was a very exciting discovery.
The next chart shows the immediate aftermath of a collision between these two grains. The little flash there in the middle is to represent the charge exchange. We see from the curved arrow that an electron migrates from the little guy to the big guy, leaving the little guy with a positive charge, the big guy with a negative charge. The arrows in both sets of pictures are velocity vectors so that once the charges exchange, these grains move apart, retaining their charge.
The effects, as I said, could be lightning. What's interesting is no one has detected lightning yet on the Martian surface. It ought to be, by our calculations, very faint, not really able to be seen in the Martian daylight, but during the Martian twilight or during the Martian night, particularly right after sunset when the atmosphere is in the process of freezing out and material is being separated, larger material being brought down to the ground, smaller material being left aloft in the residual atmosphere. One ought to expect perhaps flashes of lightning would occur. A flash of lightning could be an interesting situation we became interested, and this is something for perhaps some of you to work on in the future, because no one has done this yet on Mars, we became interested in one aspect of the Martian atmosphere. I want you to go to the chart now that's entitled, "Paschen's curve." It should show a vertical and a horizontal axis and a red concave up-curve. Paschen was a French physicist who studied electrical discharges in gases. In the particular types of discharges, he studied, he looked at the relationship between the distance between electrodes and the atmospheric pressure versus the electric potential difference at which the breakdown occurred. And he found that there was a relation. The vertical axis is the valtage difference, if you will, between electrodes. The voltage horizontally is the product of the pressure and the distance between the electrodes and you get this beautiful curve. It's different for different materials in terms of being higher, perhaps, or lower or shifted to the left or shifted to the right, but all materials show about the same shape.
Let's go to the next chart, which shows specifically the Paschen curve minima. This is the smallest potential under a set of given conditions at which a discharge can occur. We have reason to believe from previous work that on Mars, a discharge could occur at a voltage as low as 100 volts, this at a pressure distance product of somewhere in the vicinity of ten to the minus 5 atmosphere meters.
Now, if you take the surface pressure of Mars to be one one hundredth of an atmosphere, that is, ten to the minus 2 atmospheres and divide that number into 5 times 10 to the - 5 you gets a difference of half a centimeter. On a rover the size of the Pathfinder, half a centimeter is a substantial distance. Remember this rover is the size of a large breadbox or microwave oven. So a half centimeter might represent the difference, say, between two circuit boards. If one circuit board acquires charge and the other doesn't, and the atmosphere breaks down between them, something could happen to the rover. Now, in fact as we operated the rover, we had several upsets. None of them were demonstrably due to discharges but they weren't demonstrably due to anything else, either, and that leaves a very open question in the minds of some of us, myself included, as to actually what happened there on Mars.
To obtain this curve in the Martian environment is one of the things that I have advocated but that NASA has not yet taken on to do. To do it they would have to send high-voltage systems to Mars. We're not ready for that. But this is an experiment that some of you might conduct either in a laboratory under simulated conditions, taking extreme care, of course, to make sure that you don't contaminate the gas environment in any way, or that you might design a system to actually fly to Mars on a robotic spacecraft, a lander, perhaps, or a rover. I would challenge everybody in the audience to think about that. This is a piece of data that we will need in order to do any kind of real high-power electric system designs on the Martian surface. Let's go to the next chart. The Sojourner Rover, one of the issues that we looked at was frictionally generated electric charge. I want to go right on here to the next chart. We came up with a rover-charging scenario. By the way, in the laboratory we got voltages between two and five hundred volts for our simulated little rover. 200 to 500 volts is above the Paschen minimum. This was a big red flag to the mission developers because they realized we were going to be operating in a situation in which we might have substantial electrical discharge within the rover or from the rover to its environment. This is about the point that I became very seriously involved with the Pathfinder mission and became recognized as one of the mission scientists.
The scenario that we developed is that each wheel rolls over the surface dust, bearing about one-sixth of the rover weight. That is about one pound per wheel. The dust beneath the wheels become slightly compressed and in the compression grains rub against brains. Large grains become negative, small grains become positive. The small grains are light enough to cling to the wheels, charging the rover, raising its potential as a positive voltage above the ground. The large grains remain behind in the wheel tracks, holding a negative voltage until some mechanism in the environment eventually discharges them.
Let's go to the next chart. On this chart, you should be looking at a picture of the undeployed Pathfinder rover, here showed, in fact, in its stowed condition. It's all squashed down there on the pedal of the spacecraft. On the back you see the twin peaks and then the very rocky field that be eventually became the geologist's dream on Mars. We sent the rover throughout that field, taking samples and looking at the various materials that were there.
I want you particularly to look at the wheels of this little robotic machine and note their silver-gray color. This is the color that they should maintain throughout the mission, unless certain things happen. Let's go to the next chart. This chart, the next chart, entitled, "Dust collection in the laboratory," shows our experimental set -- our experimental setup shows the wheel simulation that we used, and if you look very carefully at the wheel you will notice that the points on the wheel, the grousers, are actually partially clogged with dust.
Now, as this wheel accumulated dust, and if you look on the left-hand side of the wheel, you'll see an extensive amount of dust packing in the wheel. As this wheel accumulated dust in the laboratory, its electrical potential rose. As we wrapped the drive axle with a rubber mallet knocking the dust off the electrical charge went immediately back to zero. So it was very clear that it was electrical forces, coulombic forces if you will, that caused the forces to go to the wheel. Okay, let's keep right on going.
I'm showing on that part the potentials and the positive and the negative. Again, I've got animations on mine and I don't think you have them on yours. I also showed the direction of the rotation. Okay, let's go to the next chart.
This is another angle on the same wheel. The wheel is coming obliquely at you, so this is a scene, if you were standing or laying on the ground immediately in front of the rover and it were driving at you, this is how the wheel would appear.
Again, notice the presence of dust in the grousers. The clog wheel, and then notice also the wheel track that the rover -- the wheel is leaving behind. Notice particularly that the dust accumulates more around the edges of the wheel than it does in the center.
Let's go to the next chart now, which is Saul 22, end of day. We didn't call the Martian days days, we called them Sauls, or solar periods. And here we see four clogged wheels on Mars. The silver-gray color has been mitigated by a reddish brown material that has been picked up from the Martian surface. Very evidently, material is adhering to the wheels, the material is extremely cold, it is extremely dry. The possibilities here are electrostatic forces or perhaps Vanderwahl's forest. I cannot prove either-or, however I throw my head in with Vanderwahls because after studying hundreds of pictures like these these wheels are virtually indistinguishable in their characteristics from those that we ran in the laboratory.
Let's go to the next chart. Here we see another picture, a black and white picture of the rover. The center wheel is pointed to by the blue arrow. Around the middle of that wheel is a strip that has a black-and-white checkerboard pattern. This was another experiment that I was involved with. And if you noticed the black-and-white checkerboard pattern is more gray-on-gray, very strong evidence, again, that this wheel has accumulated a layer of dust, and, in fact, the layer of dust was sufficient to mask the results from this experiment, and the results we got from it were not at all as good as we would have liked.
Let's go to the next chart.
Let's look at the conclusions that we're drawing from this whole series of events. We begin with some theory, and as part of the that we predict charging. We used the moon for comparison, we used the earth, and what I didn't mention earlier is that volcanic ash clouds on earth have been seen to produce lightning. In fact, there's one -- and I can't think think of the name of the volcano. It begins with a P. Perhaps some of you know it. Actually it's been filmed during its eruption, and there's a lightning bolt in the ash cloud, very beautifully -- it's been on National Geographic several times. We also know that dust storms, desert dust storms produce lightning, and again there are actual images of the lightning.
We go into the laboratory, we make some predictions. In the laboratory, we confirm the predictions, we make the discovery that the charging seems to go with the size of the dust grain. We identify a mechanism that looks not unlike a thundercloud on earth. We extrapolate forward to some of the weather phenomena on Mars, we make predictions, and put mitigating devices on the Pathfinder Rover. When we observe the rover operating on Mars, we find that at least visually we're seeing a behavior in the wheels that is very similar to the behavior that we saw in the laboratory.
Because we didn't have instruments, it leaves the question, does charging actually occur on Mars, and if so, how? This question has now really gone round the world. There are at least three sites in the U.S., one in California, one in Maryland, and one in Alaska, that are addressing this question, building instruments of different sorts for future missions, and I know that there are some people in Europe that are equally interested that have proposed designs, but I have not kept up fully with their particular work.
Let's go to the next chart. Again, repeating what I said, because of mass constraints, the rover instrument suite was already full. We were not able to carry instruments to Mars. So future instruments will have to be sent on other robotic packages. They will have to be designed for the Martian environment to go ahead and characterize the nature and the type of electrical activity that might or possibly should occur at the Martian surface.
Let's go on to the next chart. These we'll go through quickly. We do the robotic missions now in the hopes of learning as much as we can about Mars so that one day we can design, plan, and send a piloted expedition. Some of you may be part of that expedition either as ground support, mission support, or perhaps even as one of the astronauts traveling in a ship somewhat like the one that you see on the screen before you. This is a multi-component ship with an aeroshield in the front, nuclear-powered rocket engines in the back, earth-facing antennas, detachable modules that can be sent down to the Martian surface for exploration, for habitats, and so on.
Now let's go to the next chart. This is perhaps what the first landing on Mars will look like. Those astronauts will be wearing space suits that will be essentially immune to any kind of charging effects that might be encountered as the astronauts travel out across the duracrust and loose dust at the Martian surface.
Let's go to the next chart. Here we see a family on Mars. This is looking much, much further into the future, possibly to the time when there's an actual living colony on Mars. These people are somewhere near one of the large volcanoes on Mars, which see seen in the background, observing a dust storm in one of the deep valleys, perhaps the Mariner's Valley. In & In case you didn't guess I used PowerPoint to put a lightning bolt on there to remind you that the dust storm might well be the source of the electrical activity, and that perhaps the instruments that the youngster is holding are instruments to image the flashes that are coming out from within the cloud, perhaps this youngster is doing this as a school project there, as part of his activity in the partion colony. Let's go on to the next chart.
Some of the issues that remain to be solved, maybe by some of you if you choose to go into these areas of research, what is the nature of Martian surface electricity? This is something some of you could think about already by reading, studying, doing calculations, obtaining materials from NASA from the many NASA web sites.
Do electrical discharges accompany dust storms or dust devils on the surface? Here a good study of electrical discharge is in terrestrial dust devils. Terrestrial dust storms and even tornadoes and hurricanes might be very instructive.
Can some of these storms be detected by such means as radio static? If you go out during the thunderstorm season when the clouds are heavy and the rains are falling all about, turn your AM radio between stations, you could actually pick up substantial amounts of static from local thunderstorms. Could this be done on Mars? There are many conditions that would have to be fulfilled for that answer to be "yes," but there again, those of you that are interested in radio, you might think a little bit about the ionosphere of Mars, a little bit about the possibility of subsurface liquid water, and adducting radio waves between those two layers in the Martian environment. Triboelectric charging pose a hazard to future large rovers, robots, landers, or possible astronauts, that's a question that we will be answering within the next decade, a question which many of you could easily become involved with even as a school or as a college project. Let's go on to the next chart. This is my last chart. Those of you that have enjoyed this presentation and that might want to talk with me further, please feel free to e-mail me. I do make it a point to respond to all correspondence that I get, bar none. Send questions, send comments, and I will be very happy to correspond with you.
If you enjoyed the presentation, please write. If you did not enjoy the presentation, please write. Your comments, pro or con, will help me develop future materials for other seminars such as this. We have about five minutes left now in my presentation window, and I believe we're supposed to go into about a half hour of questions and answers. So, Linda and Mark, if I could turn the floor back to you, I'm done on this end at the Glenn Research Center, and I'm ready now for any questions and answers that our audience might care to pose.
NASA Moderator: Okay, we have lots of questions, and let me -- and a lot of people asking very related questions. Let's start with -- let's start with Brad asking how much electrostatic charge is produced when the rover moves across the surface?
Joseph Kolecki: I could give you that answer in a roundabout way. Assume that the rover charges to about 130 to 150 volts. And I can give you the capatatance of the rover which is 33pecoFarads. That's ten to the ninth or ten to the 12th? I don't remember. Let me check the pico. I use these things and very seldom actually think about what they stand for. It's a trillionth. So a picofarad is one times ten to the minus 12 farads. You I'm sure studied farads as a unit of capacitants in physics. 33 times ten to the minus 12 farads, the voltage is 150 volts. The charge, Q, is the product of voltage and capacitants, and you could work out there how many actually couloms of charge would be accumulated by the rover. It has a roughly one meter square surface so you could even figure out the charge density.
NASA Moderator: Okay, related to that, John is asking, "Is Pathfinder capable of dealing with the electrostatic problems it may have? And if not, what can be done to prevent damage to the rover?"
Joseph Kolecki: Well, Pathfinder fared okay, we think. One of the things that we did to protect the rover was to take tungsten wire, four lengths maybe about an inch and a half long and electromachine them down to electroscopic points. Now, the tungsten wire was 15 thousandths of an inch in diameter, so it really was only slightly larger than a human hair. We sent them down to a local university, Case Western Reserve university here on the east side of Cleveland, Ohio. They were put into a rig where a plasma arc actually machined this very, very fine point. We made six of these devices. We sent them to the mission engineers at Jet Propulsion Laboratory and suggested that they mount them on the rover as discharge whiskers, essentially little tiny lightning rods. The actual whiskers were mounted on the antenna base of the rover. Four of the six were used. Two were kept as spares for an engineering mockup should anything of that sort be required.
What we observed in the laboratory when we mounted similar whiskers on our mockup was that the steady state voltages were brought down from values on the order of 150 volts to values that were between 60 and 70 volts. Sixty to 70 volts is below the Paschen minimum. If everything worked on Mars the way it worked on earth, with those points, and with its very, very slow motion -- this rover went a couple of yards a day, no more -- it should not have acquired sufficiently large amounts of electric charge to cause any real damage or any real problem.
We had hoped to image the points during night operation to see if we could detect a glow, what the lost the Lander and rover to the approaching Martian winter before we were ever able to do that.
What we saw at Mission Control were computer resets, and these were very mysterious kinds of things. The computer would run on a clock, and it would run and run and run and then shut off. And then it would restart, and it would be back at zero. And, you know, the question was, why is it doing this?
There were tentative conclusions offered. I offered the possibility of a local discharge. Because we had no instruments or no real data to support that conclusion, it could not be taken very seriously. However, it remains now, in all the published material about the Pathfinder, and certainly it's going to be something to be looked at in future missions, there will be, I'm sure, various kinds of protective devices, active devices would be better. However, if passive devices are all that can be put on, whiskers of the type we used on Pathfinder certainly seem to do a reasonably good job, and there will be other ground circuit detection devices to look for pulses or those electrical signatures that might correspond to static discharges. Right now, what happened to those computers as far as I understand and as far as I am concerned remains an open question.
NASA Moderator: Okay. Jenny asks, "Will the Pathfinder be used again in future missions to Mars?"
Joseph Kolecki: The Pathfinder, no. It was designed -- the rover was designed to operate for seven days, and the Lander was designed to operate for about two months. Now, it turns out we got well more operation out of both the rover and the lander than we expected. We landed just east of that large Mariner's Valley. It turns out east of the valley there is a second valley that turns sharply toward the northwest, called the Aris Valley. That valley was formed in some past epoch when a very large amount of liquid water was discharged, perhaps an ice dam broke or a meteor struck the planet somewhere in the local vicinity, melting a huge quantity of ice. And it's speculated something like a mile-high wall of water went down the mountain side, carving a roughly mile-deep chasm. In the outwash, when the water flowed out and dissipated, that is where we landed the Pathfinder, with the idea that we could have a lot of materials from the uplands, the lowlands. There was a crater just over the horizon that on a real clear day we could see the edge of. We had material from the crater ejected, if you will. We had material from the nearby volcano. So this slow-moving not-too-widely-ranging rover could look at all kinds of great stuff. We landed right at you could say either at the tail end of Martian summer or right at the cusp of Martian high autumn.
Now, it is known, or it was known to us that at that particular site, as the sun locally moved southward day by day as Mars went about its orbit, local temperatures were going to get colder and colder and colder. With the day, there were steep rises in temperature. With the night, there were steep drops in temperature. As the lander and the rover became colder and colder, and as it was worked by these temperature swings, there were expansions and contractions, it was known that eventually there would be a failure most likely in one of the circuit boards or some of the connecting electronics where we were using ten thousandths of an inch diameter gold wire and that once that happened, we would lose both spacecraft. So we operated them as long as we could. We got over 16,000 individual photographs from the IMT -- that is, the camera that was moupted on the lander -- and we got several though from the camera that was mounted on the rover. We got all kinds of APXS data from the rover spectrometer which was really the big instrument there on Pathfinder. We got tons and tons of meteorological data. We actually hung out wind socks on the lander and we were able to image those and watch those on a daily basis. Once, however, we lost the lander, and the loss was odd. We would lose it, regain it; lose it, regain it; lose it, and finally it stayed lost. Once we lost it and were not able to regain it, it can only be assumed that the rover, getting no further commands, went to its default mode and started to circle the lander until its own batteries failed. If that's true, then when astronauts one day arrive there or a rover arrives at the landing site, it should find the lander and the rover somewhat close by, possibly covered with light layers of dust. And that, of course, remains to be seen.
Whether or not we will send another Pathfinder-type mission at this point in time is unknown. The next missions to go to Mars will be orbiters to enhance what we've already learned from the Global Surveyor, and rovers that will be much larger than a breadbox. These will be very serious rovers waying not six pounds or 18 pounds on earth as the Pathfinder rover did, but several hundred pounds. They will be much larger, they have have much larger instrument suites, be capable of going not six feet a day but maybe ten or 15 miles a day. So we're looking at this next generation of much larger instruments.
We're also looking at very, very light mylar airplanes to fly in the thin Martian atmosphere, and their design is really odd. They're very light. They're almost all wing because there's very little lift to be gotten out of the Martian atmosphere but they can certainly carry instrument packages over long-distance. They would not fly at night because the Martian atmosphere freezes out and becomes so thin that there would not be enough lift, but in daylight, if they're solar powered they could take off and they could fly and even conceivably be controlled from earth via some kind of an orbiting link. We're also looking at balloons to float in the Martian atmosphere during the daylight cycle.
Pathfinder was one-of-a-kind, remains at the present one-of-a-kind. It may be used again in the future. I would like to see it go into -- it would be nice to drop one down into the Mariner's Valley which is one of the most extensive features there on the Martian surface, it would be nice to drop one also on the flanks of Olympus Mans and explore up and down that great volcano. However, whether that's going to be done is as much determined by the scientific and engineering use of the data that we would acquire as it is by the political winds that blow in Washington and how the funds are actually allocated. Those things, of course, remain to be seen.
NASA Moderator: Okay. Christian wants to know how long have we been aware of electricity on Mars.
Joseph Kolecki: Well, we really got aware of it with the Pathfinder mission. The work that was done here at the Glenn Research Center was land-breaking work in that respect. That's a nice claim to make for this particular field center because the real space centers are JPL and Goddard. Those are the guys that are involved with doing the space missions. We are a technology and development center. We develop power for spacecraft, we develop aircraft -- wings, engines, fuselages, power systems, and so on. Yet we have a small contingent of space scientists here, and I'm one of those scientists. So for this particular center to be able to advance the science of Mars with something as substantial as identifying that electric activity in the Martian environment is going to be a significant factor in future exploration is a very significant thing to have been done. The awareness that we had prior to Pathfinder comes from Viking in another one of those results that was so enigmatic, so strange that it wasn't really ever published. And I didn't know about it, and very few people did, until I spoke with a gentleman by the name of Hank Moore. Now, Hank Moore was a geologist, the late Hank Moore -- he unfortunately passed away a couple of years ago.
Dr. Moore was a geologist who was of Viking fame. In fact, Hank Moore wrote the textbook on Mars from the Viking data. He was our team leader, so needless to say, we were very excited about being on this particular team.
In one very late night discussion, he and I over coffee and fruit were talking about the electrical activity on Mars, and he related to me the following story.
He said, "Well," he said, "we made observations during Viking that we never really were able to interpret." He said, "You know, the dust that blows near the surface under goes a motion called saltation," s-a-l-t-a-t-i-o-n. What happens is that the gain is lifted aloft, drops back to the surface, bounces, is lifted aloft, drops back, bounces, is lifted aloft, and so on. Dry sand in a terrestrial desert or dry snow in the terrestrial north exhibits a very similar movement.
What was observed in Viking was sand grazing across the surface with no saltation whatever, flowing exactly like a fluid over the surface a few millimeters above the surface. Dr. Moore said it was never clear why that was happening. However, the speculation was that electric fields were suspending these dust grains, and they were simply being carried along on a mattress, if you will, of electric field, and just skimming on by. These observations were made most often at sunrise.
Now, think about what I said about the moon earlier. The astronaut in the command module made observations of cold dust being levitated at lunar sunrise, levitated to tens of kilometers on electric fields.
Here we have Mars with an atmosphere that might keep the dust from rising very high, but here again, an extremely cold, dark surface from the Martian night, sees solar -- or sees Martian day coming as the Martian sunrises over the horizon, solar ultraviolet let causes a photoelectric charging, the dust is levitated, and the winds that are sweeping from the sun toward the night side or from the night side toward the sun, whichever, carry the dust along, and you get rivers of flowing dust for a few hours until the sun is well up in the sky. I was very excited by that observation, needless to say. That observation may actually have been the first observation done back in the 1970's of electricity on the Martian surface.
However, nothing much was done with it. The work that we did with the Pathfinder took that initial observation and took the science that could be derived from it, I think, and advanced it a considerable degree to the point where now we are very seriously looking at robotic-borne instruments that range from instruments on diggers that will looking for frictional electricity to antennas that will actually listen for radio.
NASA Moderator: Alex is asking, "Would it be possible to use the static electricity on the Martian surface to charge batteries or even to act as a secondary power source to the rover?"
Joseph Kolecki: It might be. We used some of the native electricity on earth. We can't harness lightning yet, though if we could, we'd have a wonderful, although somewhat random power source. But we could generate, we do generate frictional electricity on earth. One of the experiments, and I suggest you do not try this, okay, you could kill yourself doing it, but the experiment very simple savings and loan to take an old garbage can, cut the bottom out, stand it up on a metal rod above the ground and put a metal plate below it that's also grounded. Take a hose and run water down through the garbage can. You can accumulate a lethal electric charge that way. As I said, don't try it. It's a primitive Vandergraph generator and it can really knock you on your backside. But tweck generate electricity like that on Mars in some way using airborne dust in some kind of a closed cycle, the answer is yes. Now, what was the student's name, Linda?
NASA Moderator: I believe -- oops I've jumped down here. I'm thinking it was Alex.
P4: Okay, well, Alex, can Alex hear me, or are you going to relate this back to you.
NASA Moderator: He should be able to hear you, yes.
Joseph Kolecki: Alex, I would challenge you. That's such an extremely good question and really the answer is so largely unknown, I would challenge you to do some thinking about it and see if you can't come up with some mechanism, some simple designs -- they're going to be very primitive at this point until we can test things out -- that might actually be able to be used to harness Martian native electricity. When you've got them, share them with your science teacher, e-mail them to me at NASA. I'd be happy to see them. You may have defined the type of problem or question that you could actually make a career out of starting with college and then advancing beyond college into some sort of research or design activity later on in your life maybe five to seven years from now. I think that would be very exciting.
NASA Moderator: Okay. I have two related questions here, I believe. Rob Ball asks, "What steps are being taken to protect computers from electrostatic charges?" And Dan asks "are there any ways of using the new genetic type DNA computers instead of silicon-based computers so static is not an issue?"
Joseph Kolecki: Well, in terms of protection, there are some pretty standard ways of protecting computers. One of them is to hang discharge points on sensitive areas and so essentially aim the points, you can shape the electric fields any way you want.
Another is to take sensitive electronics and enclose it in what is called a Faraday cage. This is named after the scientist Michael Faraday, who is very famous for a very peculiar kind of demonstration. You might have seen this. It's done sometimes at science museums. Faraday built a large cage, like a bird cage, in which he could go and sit down. Faraday sat on a chair, metal chair, grounded to the cage, connected the cage to a Vandergraf generator, told the outside operator, "Charge the cage." Well, the cage would be charged until bolts of lightning would be coming off of the cage in all directions, and there Faraday would sit in the middle of the cage writing in a book or doing whatever, totally unharmed.
Now, that cage has the property that the electricity gathers on the outside, nothing gathers on the inside, and inside there are no electric fields. Now, we can build those kinds of fair day cages in miniature. In fact, they're very simple to build. You could simply take tin foil, aluminum foil, make it into a little box, and put a little tiny circuit board inside, and the tin foil will act as a Faraday cage. We can enclose -- in fact on the Pathfinder after we got our initial results from the laboratory, the electronics were hardened. What that means is that resistances were put in the ground loops to keep voltage surges from coming up through ground into things and sense active electronics were in fact put into Faraday cages, and that was a design add that was put onto the rover after we made the initial assessment that there could be a charging hazard.
As far as the second question, I think the new biological computers are too much in their technological infancy for us to make any decisions about. Boy, speculation could run wild with that one. I could actually imagine sending an embryonic computer to Mars with enough material coated in the DNA so that the computer could grow like an organism and develop its own defense mechanisms to whatever contingencies or exidgence ease it finds in its local environment. That's not entirely impossible and I don't think it's entirely a silly idea. I don't know what the sensitivity of a biologic computer would be versus a standard computer. I understand silicon and gold wires far more right now than I do the types of cells or the types of neural nets that one might grow in a petri dish. But I think you've raised a very interesting question, and you may well have [O-EUFD] another very valid area for future research. If you are -- if you are the type of person that would want to go into this, say, as a college research area or even as a career, you might find it a very productive and very lucrative career. That's exactly how scientific revolutions begin. You know, you ask a question like this, "Well, okay, we've got all this stuff on the Pathfinder, we see all this electrical charging stuff, what if I subjected a neural computer, a neural net of some sort that I grew in a petridish to electrical discharge, how would it respond, how would that affect the computer?" That's a research project. That could carry you on for the next 30 or 40 years of your life, possibly even catapult you into some kind of fame if you come up with a break through. It's a very, very good question and again I would turn at least part of it back to you as a challenge to say, you know, think more about it and possibly consider it as something you might pursue in the future.
NASA Moderator: Terrific. We have several questions here having to do with teraforming Mars, all the way from Alex's question, what is teraforming through Charles' how far have we gone into teraforming, and Dan asks what are your thoughts on fer aforming Mars and is there any time scale set for doing something of that magnitude?
Joseph Kolecki: All right. Well, first of all teraforming is derived from two words, tera, and form. To form is an English word. If I take a piece of wet clay, I can form it into a pot. Tera is a Latin word, in fact it is the Latin word for earth. So terra forming translates to earth forming. When applied to a planet like Mars, terra forming becomes a process whereby we alter the Martian environment to make it more earth-like. Now, the first question is with committee alter the environment on a planetary scale? The answer would appear to be "yes." Have we done so? The answer again would appear to be most definitely and emphatically, "yes." The question is, where have we done so? The answer is right here on earth. What is happening on earth and what has been happening for roughly the last 200 years, particularly with the dawn of the industrial revolution and then the development of effectively global technologies, manufacturing factories and so on in the 20th century and now extending into the 21st, has been done in a fairly random and haphazard way. However, there's very good evidence that we have actually caused an increase in the average surface temperature of our own planet of about 1 degree centigrade. This is a very substantial change when considered on a planetary scale, no doubt about it. We may be responsible for having produced an ozone hole over the South Pole, and it's not at all clear from the evidence in hand so far whether the ozone hole is a natural phenomenon or whether it's there as the result of materials put into the atmosphere from everything from automobile exhaust to hair sprays. That remains to be seen. We do know that there's an atmospheric hole on Venus and we do know that there's at least one on Jupiter. They are natural. There's nobody there using hair spray or belching automobile or factory exhausts or emissions to cause it. So we can't say about earth's ozone hole yet one way or the other, and there are two schools of thought, as there are so often in these things, that will argue very vehemently in either direction.
Can we terra form Mars? Theoretically the answer is "yes." How would we terra form Mars? Well, we would try to get greenhouse gases to Mars, increase the density of the atmosphere in some way to warm the surface. We would probably not transport those gases from earth. We would either find them on Mars -- and one way to do it would be to mine the ice on Mars,eelotic rolyse into hydrogen or oxygen and then combine the oxygen with carbon and make carbon dioxide and leak it out into the atmosphere of Mars. It would take a period of time to accomplish an increase in the atmospheric density, but in the terra-forming process, time is justice variables, one of the things that you assume you have.
Another way that we could very quickly change the environment is capture a cometary nucleus. Comets move very rapidly through the solar system. We hear about them quite often in the news. With nuclear thrusters, if we could reremotely rendezvous with a comet nucleus, say, as it is coming past Saturn or past Jupiter, we could perhaps land a device on the nucleus using a nuclear rocket to alter the path of the comet, bringing it into a collision course with Mars. Now, once the comet had collided with Mars, all the residual ices and waters and gases would at least for a period of time become part of the Martian environment. Robert Zuprin has written a number of books on this very topic and has claimed that it could be done as early as within the next tun years. I do know Robert Zuprin personally. He is a very brilliant individual. He's extremely optimistic, and as far as most of us are concerned, his time lines are just way too short. He wants it within his lifetime, and no one can blame him for that because he has exciting ideas.
I think realistically if we were to terra-form Mars, we would do so within say the next century, two, maybe century and a half. It's a project you might be involved with as a student, at least the first generation of, and maybe then you would do as I'm doing and speak to future students as you get older and say we've brought it this war. These are the remaining issues. This is what you need to deal with, and that next generation of students might carry it more to completion.
How do I feel about terra-forming Mars? It turns out that there are two schools on Mars. They call themselves reds and greens. The greens want to terra-form Mars and make an eternal garden, essentially, out of it. The reds want to leave it alone until we've at least gotten there, learned something about it.
I am very strongly in the school of the reds. Here is this planet that's been around for 5 billion or so years, which is a total mystery. We've barely scratched the surface with three landers and a couple of orbiters. There's so much it could teach us about itself, about its own history, that before we go and muck with it and meddle with it, we ought to learn as much as we can from it and then go into maybe make it go a suitable habitation.
I think that eventually we will terra-form Mars, and I think that eventually it's probably the right thing to do. I, for one, if I lived in that age of time, would be very excited about taking a trip to Mars and spending a few months there even as a vacation, or as a researcher. But I think we ought to worry the timing a little bit. I think we should learn what the planet can teach us in its pristine state before we go and mess with it. Another consideration would be life on Mars. Should we find living organisms on Mars, who has rights? Does the organism have squatter's rights? It should. Well, what if the organism is an amoeba or an algae? Does an algae have squatter's rights when people could come and turn this into an oasis? That question hasn't been answered, except that a writer by the name of Gene Roddenberry who created Star Trek a few decades ago now, did attempt to answer in his fictional story by setting up a Prime Directive, that if there is life, even prebiotic matter on a planet, that planet is off limits u don't touch, you don't interfere, you let it develop. And if there's a culture, you don't affect the cultural evolution of the beings living on the planet. You observe remotely and with great care. If Roddenberry is a prophet for the future, then perhaps we will one day have something like a prime directive written into space law. And if Mars is alive, that law will then suggest hands off and will provide us our own answer to terra-forming. We might then consider terra-forming local regions of the planet, or not at all. And again, that would remain to be seen. It's a beautiful thought and a very, very complex issue when you begin to think about it.
NASA Moderator: Okay, your answer to that question, I think it sounds like you've been reading an awful lot of the questions that are in the chat room.
Joseph Kolecki: Actually, no, I'm catching them just for the first time.
NASA Moderator: Right. Well, it's interesting, because a lot of people have been asking about whether or not there's life, and, if so, would we not be interfering with it in terra-forming so you really hit a lot of the questions right on the head with that one.
Joseph Kolecki: Well, you know, I'm glad that the students are thinking about that, because it suggests that in their thoughts about Mars and in their thoughts about terra-forming and even a possible future of human habitation up there, that they have also some level of compassion for organisms that might be already present there. And I think that that's maybe one of the most permanent and enduring of all human qualities, our ability to exercise compassion, our ability, if you will, to love, to understand that, you know, this may not be a human organism, but maybe it should have a right. Because as we expand, particularly into the solar system, which I firmly believe we're going to do, we have to move outward with the best of what we have, the best of what we have includes technology and the drive to explore and the ability to reason and learn, but it also includes compassion. So I commend the students who have offered those thoughts, and I would ask them very seriously to continue thinking in that particular vein.
NASA Moderator: Terrific. I'm going to wrap it up here with one final question from Kate in which she asks, "How long do you think before we are ready to send humans to Mars?"
Joseph Kolecki: I would hope within the next half century. We are sending robotic missions. There are the ones that have already been sent. There are a lot more on the books, and they're very, very extensive. With the discovery of extensive fields of ice near the poles, with the discovery now of liquid water having flown somewhere within the last 10,000 years -- that's as good as yesterday, geologically -- the biologists are very excited about the possibilities of life, and Mars keeps coming nor and more into the limelight. You hear about it on the news, you read about it in various magazines and books. People talk about it more and more. Scientific circles get very excited. There are all kinds of conferences constantly in the U.S. and around the world about Mars.
People will eventually have to go to Mars because robots cannot do the full job. A robot can do a great deal, but what a robot lacks, a human offers, and that is intuition. If a robot were to go past a living organism running its program, it might not make the intuitive leap to say, "Wait a minute, stop and let's take a look. What was that?" A human would.
And ultimately, that may be the strongest reason, the strongest driver for sending humans. We have a lot to learn before we can send them safely. I think within the next half century, maybe as close as the next quarter century if we're fortunate, we will be ready to send people to Mars. Kate, if you're at all interested in that, you may one of the people that flies to Mars. You know, the astronaut crew to go to Mars is somewhere between kindergarten and college and living in the world right now. So any person in that age-group is a possible candidate for being a part of the Mars mission, whether as an astronaut or ground support or supporting scientist, researcher, designer, anything and everything of the sort.
You are in that population of people. So think about it in those terms. And if you dare, lay claim to your portion of it. Everyone to whom I'm talking today has claim to some portion of this research. It doesn't just belong to white-haired old scientists like me. It belongs to all of you, too. All you have to do is stake your claim, do what you're going to do in college, which is where your research begins, and inject yourself into a research environment where you can carry on and you can publish and become part of the future world of science and scientists.
NASA Moderator: Okay, I want to thank you very much, Joseph Kolecki, for joining us here, and for all the students from all over the world, actually, that have asked such great questions. Thank you, and we'll see you again on Thursday.
Joseph Kolecki: All right. Well, best wishes to everybody, Godspeed from all of us here at the Glenn Research Center in Cleveland, Ohio. Have a great day.