MIT solar car readying for race day


The Manta GT, MIT's solar-electric race car, made its campus debut Monday on a sunny day outside Lobby 13, a month before leaving to defend MIT's Sunrayce title.

The MIT Solar Electric Vehicle Team hopes the car can repeat the success of its predecessor, which won Sunrayce '95, a 1,100-mile race from Indianapolis to Denver. Sunrayce '97 begins in Indianapolis on June 19 and ends nine days later in Colorado Springs.

"The team performed well. We've made changes--we're at about 80 percent efficiency--and we'll make a few more. We know we're in a competitive position," said David Hampton, a graduate student in electrical engineering and computer science who joined the SEVT in 1990 and has seen cars built by the team evolve from the Galaxy, which looked like a "ravioli going down the road," to Manta, which indeed looked like a manta ray, to Manta GT.

MIT's vehicle placed second in the eastern regionals and third in recent overall qualifying trials. As President Charles M. Vest accepted his official team jacket, he said to the assembled well-wishers, "We are seated at number three at the starting line and number one at the finish line!"

President Vest thanked the SEVT faculty advisors and the corporate sponsors, including Motorola and Ford, for their time and commitment to an educational project that "takes the formal work in the curriculum and applies it in a practical way. But it's the team members we're really here to salute. Congratulations on a great product. You are all extraordinary and effective representatives of MIT!"

SEVT members include Brian Graham, a junior in EECS; Masa Ishigami, a senior in physics; Bonnie Tom, a junior in mechanical engineering; Jorge Barrera, a sophomore in mechanical engineering, and Ivano Gregoratto, a senior in chemical engineering. Mr. Gregoratto will drive Manta GT, which he describes as "soft enough to give a good ride."

EECS senior Wandy Sae-Tan, a team member for three and a half years, reported "lots of pressure" during the last Sunrayce, which is run in daily laps and won by the team with the lowest cumulative time. "The project was a long series of engineering challenges, each one producing the next, all of them focused on how to make the car more efficient while using less power," she said. "During the race, you're also dealing with the weather. You have to strategize to conserve the batteries. If you know it's not going to be sunny tomorrow, you have to ask, `How fast should I go today?'"

Despite the demands of time and energy, "working on GT is addictive," said Ms. Sae-Tan. "It's a great hands-on project. It deserves course credit--then more students could get a chance to work on it without having to take away from course work."

SPIRIT OF COOPERATION

Both Mr. Hampton and Ms. Sae-Tan relished the community spirit that evolved among people involved with Manta GT. Ms. Sae-Tan noted how the sponsors grew "personally involved. It's so wonderful to know there are people out in the corporate world who value this kind of educational project."

Mr. Hampton appreciated the "challenges, both the practical engineering aspects and the project management and fund-raising aspects. You put in so much time together, you get absorbed and forget to do other things. The senior members help out the newer students with their course work. Even alumni in the area get involved. There's real spirit in it."

Kathleen Allen, team advisor from 1991-95, thinks Manta GT has a good shot at winning next month. "Sunrayce is a true engineering race," said Ms. Allen, a technical instructor in music and theater arts who likes "getting filthy and taking things apart." She described some of the design challenges posed by race regulations, such as a new safety requirement for a roll bar whose weight reduces vehicle speed (though Manta GT can still do up to about 60mph).

"The race itself is a big show of creativity," Ms. Allen said."The starting lineup offers 40 different opinions from 40 different universities on which priority was most important."

Seeking an advantage for Manta GT, the team focused on the car exterior's solar cell layout. The cells are soldered together like shingles, with slight overlaps at each end, a departure from Manta's traditional end-to-end layout.

"They're losing that 1/50-inch gap between cells and gaining a broad band of contact between the cells. Also, they've got a smooth overall finish so there's no jinx to the car's aerodynamics," Ms. Allen explained. Achieving this layout is "unbelievably labor-intensive," since each glass-like crystal cell must be cut across the grain and hand-soldered in the proper sequence to the next one, she said.

NEW BODY MATERIAL

A new drive system in which the wheel is mounted on top of the motor has been installed in Manta GT. The car's body has also changed. Manta was made of carbon fiber with Nomex, a honeycomb core, but Manta GT's body is Kevlar, a material used in bulletproof vests and to tether astronauts to their ships. Since it is less stiff than Nomex, Kevlar requires more reinforcement, but it's also safer, Ms. Allen said. "Kevlar doesn't conduct electricity. If you happen to short out the batteries, nothing happens." The same circumstance in a carbon-fiber car can result in fire.

SEVT advisors are Associate Professor Mark Drela and Richard Perdichizzi, senior technical instructor, both of the Department of Aeronautics and Astronautics. Mr. Perdichizzi, who is also president of the New England Lotus Group, has long been involved in racing cars. After Sunrayce, Manta GT will be shipped from Colorado to Osaka, Japan, for an August race at a Formula One track. "Once the car is built, you can't duplicate real experience," he said.

As early afternoon set in on Monday, the small crowd of GT fans drifted away to classes and other commitments, but freshman Krzysztof Sobczak stayed. He waited while Mr. Hampton completed two interviews, then spoke up. The car with the sleek coating had worked its charm again. Was he interested in the race team?

"I have done motorcycle racing. I'm a good mechanic, and I am interested in anything that moves--the faster, the better," he said.

A version of this article appeared in MIT Tech Talk on May 14, 1997.


Topics: Electrical engineering and electronics, Mechanical engineering, Contests and academic competitions

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