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Conquering the Solar System
Michael Cannell
August 21, 1995
Neither rain nor lack of funds kept MIT's car from winning Sunrayce 95
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August 21, 1995

Conquering The Solar System

Neither rain nor lack of funds kept MIT's car from winning Sunrayce 95

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On June 17 a solar-powered car built by 20 students at the Massachusetts Institute of Technology rolled into Indianapolis Raceway Park, propelled by a tankful of sunshine and an underdog's resolve.

MIT faced an uphill battle on this day of qualifying for Sunrayce 95, a biennial intercollegiate derby for sun-powered cars. Twenty-seven of 38 entries had already been selected for the nine-day, 1,150-mile race from Indianapolis to Golden, Colo., but MIT was not among the chosen. For the second time in five years a panel of judges had been unimpressed by MIT's written proposal, preventing the school from competing as a seeded entry.

MIT had one chance left: 11 unseeded teams could earn places by demonstrating their cars' fitness in obstacle and speed trials. MIT's crew had gambled on qualifying the hard way. "We had no idea what we were doing," concedes chemical engineering major Ivano Gregoratto, a junior who helped build the lightweight carbon-fiber body of his school's entry.

Unlike the top contenders, MIT had faced the unenviable job of soliciting support after its proposal was rejected. Led by Goro Tamai, a graduate student of mechanical engineering, MIT's campaign raised $75,000—average for most entrants but peanuts compared with the $1.4 million rumored to be available to the two-time defending champions from Michigan.

Building a car capable of collecting prodigious quantities of sunlight and converting that to road speed became the MIT team members' extracurricular obsession. "Some of us just punted our classes," admits Gregoratto. Over the course of a year, the team members built a wing-shaped carapace of solar cells mounted on a tubular chassis equipped with go-kart brakes, motorcycle shocks and heavy-duty bicycle-style tires on custom-made wheels. With Tamai in the low-slung driver's seat, the car weighed a mere 814 pounds. Its flat, cambered profile evoked a ray, so the team christened the car Manta.

The hard work paid off at the audition. In the fitness exercises Manta accomplished what no other entry could: On the first try it passed a proficiency test involving a slalom run, acceleration and emergency braking. "Right then we pretty much knew that we had one of the best cars," says Tamai.

But he didn't know how fast Manta really was until that afternoon, when his crew arrived five minutes late for the road race to determine starting positions. Making matters worse were two flat tires, which cost the team 14 more minutes. Despite these handicaps, Manta completed 115 laps of the 1.9-mile circuit within the six-hour limit. Only California State Polytechnic at Pomona outpaced MIT, with 117 laps.

On the morning of June 20, U.S. Energy Secretary Hazel O'Leary waved the green flag, sending Cal Poly off first. The Californians maintained their lead to the end of the 65-mile leg, reaching Terre Haute, Ind., at an average speed of 36.13 mph. MIT finished five seconds later, followed by the team from Missouri.

Cal Poly held onto first place through the second leg, but on day 3 MIT snatched a 7:34 advantage by covering the 165 miles from Louisiana, Mo., to Fulton, Mo., at an average of 42.83 mph. As the race moved on to Kansas and Colorado, Manta maintained the lowest cumulative time. "Those days were a total no-brainer," Tamai says. "The car just drove itself."

In Sunrayce 93 the winner averaged only 27.3 mph. But thanks to improving technology, this year's fleet traveled some 10 mph faster. MIT even incurred penalties for breaking the speed limit. Now reliability rather than speed is the key to the race.

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