Hopes, ceilings are high for balloon-drop ballet

John Kerry and Maureen Curreri both face the biggest tests of their careers tonight. But there's one difference: Kerry gets to practice.

Curreri is coordinating the signature moment of the convention, the balloon drop, and unlike the politicians and entertainers who rehearse their parts in the theatrical production known as the Democratic National Convention, Curreri gets only one shot. Tonight culminates a marathon of planning and preparation that began in March, and continued through last week's sprint to inflate nearly 100,000 balloons, stick them in 100-foot-long nets, and position them in the upper reaches of the FleetCenter.

Now Curreri prays that her calculations of everything from balloon size to wind speed are on the money.

"You dot your i's and cross your t's," said Curreri, owner of Boston Balloon Events of South Boston. "Then it's in God's hands."

Getting thousands of balloons to fall might seem a simple act of gravity, but the balloon drop is a technical challenge performed in the unforgiving glare of television. Even though everything is in place, two things could still go wrong: The balloons could fail to drop, or, perhaps even worse, come tumbling down in the middle of Kerry's speech.

Democrats have not always had the best luck with objects falling from above. In what proved an ill omen, President Jimmy Carter waited in vain as thousands of balloons stayed in the rafters at the 1980 convention in New York.

At the 1948 convention, Democrats released doves, which swooped down on President Harry Truman and senators on the platform, and prompted legendary House Speaker Sam Rayburn to snarl, "Get these damn pigeons out of here."

Curreri expects to have better luck. The reason: precision. For example, more than 98,000 balloons -- divided evenly among red, white, and blue -- were inflated to a diameter of exactly 10.75 inches, each carefully measured in templates. (About 1,500 balloons are 3 feet in diameter, inflated by a special team experienced at the task.)

The smaller size, a quarter-inch less than the balloons' designed maximum of 11 inches, heads off two potential problems, Curreri explained. First, the underinflation keeps the balloons supple so they won't explode in the rising temperatures. The balloons, however, still have enough air to allow for leakage, sparing delegates from getting pelted by shriveled hunks of latex.

Close attention is also paid to the nets, which are sewed into cylinders with a stitch designed to rip out easily, releasing the balloons. Curreri had used a zigzag chain stitch until one snagged at a 1986 Boston City Hall event; now she uses a straight base stitch.

"Everything has to be calculated," she said, "or it could be a disaster."

Curreri, however, has never had a disaster over the course of three decades and 1 million balloons. Trained as a mezzo-soprano at the New England Conservatory of Music in Boston, Curreri, 53, began her business as a singing telegram service and added balloons.

"It started with, 'Can you bring 20 balloons? Then it was, 'Can you bring 200?' " she said. "Now it's, 'Can you bring 100,000?' "

The growing importance of balloon drops coincides with the rise of television. In 1972, following a chaotic Democratic convention that pushed George McGovern's acceptance speech into the wee hours, the campaign of Richard Nixon made sure the Republicans' balloon drop occurred in prime time.

Curreri, admittedly nervous, is nonetheless confident. With a production team that has done drops of up to 65,000 balloons, she expects tonight's finale to be a crowning achievement.

"The only thing that can top this," she said, "is if my son, who is 30, finally gets married."

Robert Gavin can be reached at rgavin@globe.com.