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It's arid and cold there now, and quite inhospitable. But researchers think that Mars was once home to ancient bodies of water—rivers and lakes, and possibly oceans. And where there once was water, there may have been life. The effort to crack that mystery was the scientific objective of NASA's Mars Exploration Rover mission, which in January successfully landed a pair of small robotic scouts on the Red Planet. If answers are found, much of the credit can go to a cadre of academics from 13 American universities, with support from French, German, and Japanese colleagues. The principal investigator is Cornell University's Steven W. Squyers, a professor of astronomy. Other scholars on the science team come from such institutions as Harvard, the University of Chicago, Washington University, the University of Tennessee, the University of Arizona, and Ohio State University. Cornell and Texas A&M were among schools that engineered the robots' panoramic cameras, while Arizona State University and the University of Nevada were among those that worked on the various instruments aboard the rovers. And mission control for the $820 million Mars exploration is the Jet Propulsion Laboratory in Pasadena, Calif., which is managed by the California Institute of Technology.

Opportunity, the second rover to land, early on sent back photos of bedrock that suggested they might have been formed by prehistoric waters. No matter the mission's conclusions, Squyres told reporters, it is “arguably going to be the coolest geologic field trip in human history.” Spirit was the first of the two rovers to reach Mars. It made a textbook landing and had begun to explore the Martian surface, delivering incredible pictures, too. Nasa engineers worked out some glitches that initially sidelined Spirit. Mars is a notoriously hard place to reach; two thirds of previous missions there failed. So despite Spirit's difficulties, this one was already deemed at least a partial success.



Who knew? Harvard researchers using an algorithm they developed to design mechanical devices that perform at an optimum level, have discovered that a triangular tap produces smaller droplets than a circular one. A slightly concave, three-sided nozzle will produce droplets 21 percent smaller than those emitted by a round tap. In theory, a triangular tap could produce drops a mere 8 billionths of a millimeter. That's a fairly significant gain if the cost of the material being sprayed is a consideration, says Michael P. Brenner, a professor of applied mathematics and applied physics in Harvard's division of engineering and applied sciences. He and graduate student Henry Chen devised the algorithm.

One possible use is the manufacture of silicon chips and bio-chips that are sometimes patterned by fine sprays. It could also result in extremely high-resolution ink-jet printers. A few companies have called to ask about the finding, Brennan says, but it's too soon to say if triangular taps have great commercial appeal. More important, he says, the finding shows that the algorithm can be used to help solve problems in the design of engineering mechanisms that were beyond the ken of previous predictive formulas. In that sense, he says, the nozzle demonstration is good because, although it's a complex problem, the result “is one you can visualize. It's easy to explain to a person on the street.” Certainly easier to explain than the optimum shape for a microelectromechanical system device.



Students in the College of Engineering at the University of Colorado-Boulder are developing devices to help speed the U.S. ski team down the slopes. The United States Ski and Snowboard Association (USSA) has given $10,000 to fund two senior projects aimed at giving the team an edge in competition. One device will precisely measure the velocity of skiers and synchronize the data with videos of their runs.

It's a joint project involving students from the mechanical and aerospace engineering departments. Ski team coaches will be able to use the system to determine “if particular moves help or hurt a skier's speed,” explains Jack Zable, the mechanical engineering professor overseeing the projects.
The velocity vector will use Global Positioning System sensors inside a small packet weighing one to two pounds that will be strapped to the small of the back of a skier. The extra weight won't affect a skier's run, Zable says.

Another device, being developed by a mechanical engineering team, will measure the coefficient of friction between skis and snow. Friction affects speed, and the coefficient is affected by such factors as ski design, wax, type of snow, and humidity. The measuring device will be placed atop a ski and dragged on the snow. The measurements it takes will help a skier choose the right ski and wax to match conditions. It could also be used to help design differently shaped skis.

Zable says the USSA effort is part of an ongoing program at Colorado to fund student projects using industry or government sources. Students get real-world experience, the donors get new technology at a cut rate, and the engineering departments get extra funds to buy new equipment. “It's a win, win, win situation,” he says. Speaking of winning, if Team USA schusses to the gold in the 2006 Winter Olympic Games, it may be a victory engineered by Colorado students.



There stands in New Jersey a 56-foot-long bridge composed of approximately 100,000 polystyrene coffee cups and 80,000 plastic bottles. And cars drive on it. Really. Well, perhaps there are fewer cups and a few thousand plastic eating utensils in the mix as well, but in the end, the bridge really is made entirely of recycled plastic. The one-lane bridge crosses the Mullica River in New Jersey's Pine Barrens region. It replaced a wooden bridge a little more than a year ago.

Two Rutgers University materials engineers, Thomas J. Nosker and Richard W. Renfree, are responsible. They succeeded in inventing a durable and strong building material by blending two recycled plastics that, on their own, wouldn't hold a child, let alone a car or truck: high-density polyethylene (HDPE) and polystyrene. HDPE, used to make bottles for things like detergents and water, is flexible. Polystyrene, used for things like coffee cups, hangers, and disposable utensils, is brittle.
Mixed at a ratio of roughly 65 percent HDPE and 35 percent polystyrene, however, the plastics form a surprisingly robust and versatile material.

The pair has licensed the technology to Polywood, a New Jersey company that initially used it to make picnic tables and park benches, before venturing into bridge construction. It was first used to partially construct bridges in Missouri and New York. The New Jersey bridge is the first constructed entirely of the material. It is lightweight and inexpensive: the Mullica River span cost just $75,000. An equivalent wooden bridge would cost $350,000.

Environmentalists should love it because it's free of the chemicals used to repel pests from wooden bridges. Those chemicals are environmental pollutants. There's also the benefit of diverting junked plastics from landfills. In addition, wooden bridges—there are 500,000 of them in the United States—typically last just five years. Their plastic replacements should last 10 times longer.
Nosker says other bridge projects are in the offing, but it's too early to announce them. Other potential uses, he says, include docks and backyard decks. “You can't use treated wood any more. Kids who play on it have 10 times the risk of certain cancers.” Ultimately, Nosker's convinced the plastic is strong enough for use in major highway bridges.

One drawback: To keep costs reasonable, it's made from a mix of products, regardless of color. The result is a gray-green hue that Nosker admits is ugly. So carbon black is added to the mix. Like Henry Ford's Model T, you can have a plastic bridge in any color you want. So long as it's black.



Michael Shafer, a 26-year-old chemical engineering graduate student at Michigan State University, found himself basking in the limelight of international media attention in December when it was announced that he had found the world's largest known prime number—a whopper that's 6,320,430 digits long.

He was taking part in GIMPS, the Great Internet Mersenne Prime Search, That's a distributed network of 200,000 computers and 60,000 volunteers around the world that utilizes otherwise unused processing power to hunt for gigantic primes. It was happenstance that the number appeared on Shafer's Michigan State office computer. “It could have been anyone [taking part in GIMPS],” explains Eric Weisstein, who runs a mathematics Web site, “He would have had a better chance of winning the lottery.” Indeed, Shafer says, “People ask me how I did it. I just say, well, I let my computer run.” The number is 2 to the 20,994,011th power minus 1.

Prime numbers are positive integers, greater than one, that are only divisible by themselves and one. This is only the 40th known Mersenne prime number. Mersennes take the form: 2 to the p power minus 1, with p being a prime number. Shafer's number beat by more than 2 million digits the previous record-holder, which was discovered two years earlier. Weisstein says this record will be broken, too, probably within two to 10 years.

Mersenne primes retain an aura of mystery: It's believed there are an infinite number of them, but no one's proven that. Prime numbers are useful in cryptography, but not ones this big. This giant is merely interesting but not significant. “It has no real-world applications,” Weisstein says, but its discovery is a testament to the power of distributed computing. How big is this number? It would take more than 1,100 sheets of completely filled, standard-size copy paper to print it out.



AUSTRALIA—An Australian engineering research team has come up with technology that will enable the production of inexpensive, intelligent, small “drone” helicopters that would eliminate risks to humans performing dangerous tasks. They describe their invention, named Mantis, as a first.

The team produced an inertial sensing system and a computer vision system, to control and provide flight stability and to guide the aircraft. The inertial sensing system behaves somewhat like the inner ear, providing balance and indicating the orientation of the helicopter in the air. The instrument uses MEMS [Micro-Electro-Mechanical-Systems] sensors and is fabricated from magnesium alloy.

This “brain” weighs only 2.62 ounces. Team spokesman Peter Corke adds it is “much lighter than current technology and is a major reason we were able to make the ‘brain' of the Mantis light enough to be carried by such a small helicopter.” The helicopter, with a custom-built lightweight aluminum frame and landing gear, is 1.65 feet high and just under five feet long.

The engineers and scientists involved in the project were based at the Brisbane laboratories of Australia's government-funded Commonwealth Scientific and Industrial Research Organization (CSIRO), headquartered in Canberra. The organization is talking with potential partners about commercial development of the Mantis.



A Tulane University professor of engineering and computer science has come up with a way to harness the energy of kids. Shunmugham R. Pandian got the idea while watching his 6-year-old son romping at a playground. He connected pneumatic cylinders to a see-saw. When kids rode it, it pumped air into a compression tank where an inflator converted it to electricity and stored it in a battery.

He reckons a teeter-totter in use for 30 minutes can produce enough juice to operate a laptop for 20 to 40 minutes. And it's safe and clean. The same concept can be used on other playground equipment like swings and merry-go-rounds.

Though Pandian has applied for a patent, he's already considering using something other than compressed air— which, though cheap and safe, isn't the most efficient means of conversion. He envisions schools storing the collected electricity in batteries as a backup power supply. The system could also be a fun way to teach children about converting energy to electricity, he adds.

While his idea is novel, Pandian says there is a burgeoning field of “human power conversion” which aims to use human energy to run such things as flashlights, PCs, irrigation systems, and some of the high-tech equipment carried by modern soldiers. So, perhaps one day we'll convert muscle power to firepower.



Hey, professors. Guess what? Your students like you, they really like you—enough to dig into their pockets to help keep you around. Well, that's true, at least, at Virginia's College of William and Mary. Its 6,000-strong student body passed by 82 percent a referendum to raise the student activity fee by five bucks to nearly $80. The extra $30,000 from this will be used to give bonuses of $10,000 to three professors, chosen by the school's provost with input from student leaders. It's hoped the extra funds will help stanch a brain drain that's seen some of the school's top scholars leave for better-paying jobs elsewhere.

State aid to William and Mary has dropped 28 percent over two years and faculty salaries are stagnant. The result: 13 professors have left for greener pastures. The referendum was the idea of Brian Cannon, 21, a senior government major who got miffed when he learned that one of his favorite government professors was heading for Princeton University and more money. “Students were excited to do something to battle against budget cuts,” Cannon says. They've been hit with tuition hikes while watching some of the best and brightest faculty members leave. “They're being asked to pay more for less,” he complains.

The bonuses will likely be given to younger, recently tenured faculty members who are not as entrenched as their older colleagues and are therefore more willing to move. Meanwhile, Cannon says he's gotten calls from student body presidents at other schools interested in the William and Mary action.

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