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Final Project

Justin A.

Legislator:  Frank L. Madla, Senator

(Click on the image above to enlarge.)

Project:  I have constructed a primitive model of a Mars Rover using wood pieces, aluminum foil, one soda bottle cap, paint, and a little old-fashioned ingenuity.

Report: The Sojourner Rover.

All throughout history humans have struggled against all odds to achieve the so-called “impossible”. From the construction of the pyramids in Egypt to the erecting of the Coliseum in Rome; from our first ventures into the coldest regions of Antarctica to the plantation of the American flag on the moon’s surface; man has come together to make these seemingly unfeasible aspirations an actual reality. Now, it seems, we our faced with yet another challenge. One in which goes hand and hand along with the infamous Star Trek quote: “To boldly go where no man has gone before.” We call this next challenge: Mission to Mars.

Mars is a barren planet. It is void of any considerable signs of life, lacks flowing water, and is home to some of the most unpredictable weather patterns known to man. Dust storms similar to a fine mist or fog rip through the rusty terrain at speeds ranging from sixty to one hundred miles per hour. A thin atmosphere leaves the planet’s surface vulnerable to impact from falling meteoroids, while also exposing the planet’s surface to heavy radiation beaming down from the distant Sun. And if that wasn’t already enough, Mars sits at a near minimum of 35 million miles away from our own planet Earth. So why go there? Simply put: because we can of course.

Yet, in order to meet any of our objectives to one day visit the planet Mars, we must first make due preparations. Ultimately, we must work hard to learn, plan, and then, when all things are considered ideal, accomplish. How are we making way in this full-scale preparation? Well, one contribution to this extraordinary vision has been made via a small remote controlled scientist-on-wheels. We call this instrument “the rover”. With it we have learned of many important aspects of Mars, vital to any future missions; namely, details about its atmosphere, terrain, and climate.

In 1997, NASA’s Mars Pathfinder landed on the Ares Vallis flood plain located on the surface of Mars. Released from one of its pedals was humanity’s first attempt to operate a remote controlled vehicle on another planet – an attempt also known as the Sojourner Rover. Because it was the first of its kind, Sojourner’s visit to Mars was largely a technological experiment testing to see how effective the use of rovers on Mars actually was. Even so, Sojourner also performed a series of important scientific experiments on the foreign surface, revealing and confirming an abundance of information concerning the Martian planet.

One of these experiments was called the Wheel Abrasion Experiment (WAE). The technique of the WAE is based upon the characteristics of one of the rover’s six wheels.  In fact, the experiment is the wheel itself. Essentially, this wheel is made of a variety of different materials that wear out at different rates. The wheel used for this experiment is different from the other wheels of the rover.  It has several thin plates of Aluminum, Nickel, and Platinum attached to it. Each of these metals is used because they will "wear out" at different rates as they grind across the Martian surface. As they do, a photovoltaic sensor monitors changes in the film reflectivity.  Essentially, this will determine how much they get scratched up, giving an indication of what type of surface the rover has been driving over. Results? The Wheel Abrasion Experiment has contributed significantly to our knowledge of Martian surface characteristics. Marked abrasion indicated a surface composed of hard, possibly sharply edged grains.  Whereas parts of the landing site that lacked wheel abrasion suggested a somewhat softer surface.  By comparing the wheel wear on Mars to simulations run on Earth, we now have a better understanding of the composition of the Martian surface.  This knowledge has allowed for a deeper understanding of the erosion processes on Mars and the role they play in Martian surface evolution. This information is also important for any future plans of possible structures being built on Mars’ surface.

Another one of Sojourner’s experiments is called APSX. Rocks and soil are the pages in a planet's diary. Geologists have been able to chronicle our own planet's history by studying its rocks and their formations. With an understanding of geology, one can reconstruct an ancient shoreline or delve into the heart of an extinct volcano. This was the purpose of Sojourner’s APSX. Using a sophisticated instrument that allows us to peer directly into the molecular structure of rocks and soil the Pathfinder Rover revealed many important pieces of Mars’ geological framework. As a result Sojourner measured the chemical composition of six soils and five rocks at the Ares Vallis landing site. Prior to this mission there were only two sources of information on the chemistry of the planet’s surface: the XRF-analyses of the two Viking Landers and the analytical data of Martian meteorites discovered here on Earth. The soil analyses show similarity to those determined by the Viking missions. The analyzed rocks were found to be unexpectedly high in silica and potassium, but low in magnesium compared to Martian soils and Martian meteorites. The rocks showed a high degree of similarity to rocks found on Earth and are very close to the mean composition of Earth's crust. 

Yet another experiment was accomplished by the Sojourner. This one being know as MAE. The MAE experiment involved two sensors: a solar cell sensor, which measured how much light was obstructed by dust landing on the transparent cover, and a quartz crystal monitor, which measured the mass of dust deposited on the array. The MAE was mounted on the front left corner of the Mars Pathfinder Rover, covering an area of about 12 square centimeters. Because the Mars Pathfinder and subsequent landers will rely on solar power, the rate at which Martian dust collects on the solar panels is a critical issue. The MAE experiment helped determine an approximate amount of how much dust would collect on a future rover’s solar paneling. Information needed to insure longer running and more durable rovers in future missions. In addition to solar cell performance, this experiment also gave us information on models of atmospheric transport of dust and the role of dust storms in global mass transport.

Not only did Sojourner perform these fundamental experiments, but it also, with the help of its carrier Mars Pathfinder, we were able to take thousands upon thousands of pictures. Included in these were panoramas of Mars’ surrounding landscapes, moons, sun, and up close views of the many different rocks sampled by the rover. In all, the Pathfinder mission returned more than 16,500 images to scientists on Earth.

All in all, this small rover proved a success and has paved the way to newer and more efficient rovers for the missions of tomorrow.  Such as ATHENA, a more advanced rover than Sojourner, set to find the Martian surface in 2003. I believe, along with many scientists working for NASA and independent aerospace industries throughout the world, that the use of rovers is a crucial stepping-stone towards reaching our final destination. With their help we will be able to achieve that one important part of my before-mentioned all-out preparation: “to learn”. “For Knowledge, too, is itself power.”

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Last Updated:  09/07/01