NEW YORK (AP) -- Plenty of performers have had explosive entrances. Some rise like meteors, soaring to new heights. Others find their moment in the spotlight fleeting.
Few have done all of this at once and quite so literally as Gemma Kirby, the 25-year-old human cannonball at Circus Xtreme. She hurtles out of a cannon at up to 66 mph and lands up to 104 feet away in an air bag.
"It's a very intense sensation. Very few human beings get to feel that sensation, except for fighter jet pilots or an astronaut," she said by phone recently. "It's really remarkable to feel it completely untethered to any type of vehicle."
Kirby will be celebrating a special milestone on Saturday: She's expected to notch her 500th total flight in Philadelphia -- a heart-thumping moment on Valentine's Day.
"I can never do this act half-awake or not prepared or warmed up," she said. "Every single time is a risk. Every single time is a bit of a mystery."
Circus Xtreme is a new traveling show from Ringling Bros. and Barnum & Bailey Circus that showcases extreme acts -- acrobats rappelling from a 15-foot towers, BMX riders, high-wire performers, contortionists and Bengal tigers, to name a few.
It's part of what Nicole Feld, executive vice president of Feld Entertainment, Ringling's parent company, hopes will "tap into that edge-of-your seat, thrill-seeking live entertainment experience."
Kirby, who during her act experiences a G-force of seven, about the same as an astronaut re-entering the atmosphere, is one of the circus' highlights, even though her actual flight lasts only about 2.4 seconds.
"Gemma lives and breathes the thrill of being a human cannonball," said Feld. "And there's something about her that feels like a fairy tale superhero come to life."
Kirby, nicknamed "The Jet," hopes to notch 1,000 flights by the time the two-year tour ends. After Philadelphia, the circus hits states including New York, New Jersey, Alabama, South Carolina, Virginia, Ohio, Rhode Island, Connecticut, Pennsylvania, Nebraska, Missouri and North Carolina.
Born in Minneapolis, Kirby fell in love with performing as a youngster and she danced onstage at age 7. She liked ballet, but began to find it restrictive and not creative enough.
At 13, she attended aerial classes at the youth-orientated Circus Juventasin in Saint Paul and was hooked: "I knew right away I wanted to be in the air." From age 17-22, Kirby was on the flying trapeze with several circuses.
Last year, while working toward her bachelor's degree in psychology from the University of Minnesota, she was contacted about possibly being shot out of a cannon for Circus Xtreme. She's a rare woman in a secretive, exclusive world.
"Everyone in the circus knows the cannon is the most daunting, the most thrilling, the most daring of all the acts," she said. "It's just something I never thought in my wildest dream that would be offered to me."
Kirby and her team are constantly checking the specially-designed cannon and calculating the details of her flight, which includes everything from humidity to the arena's temperature.
The cannon, whose exact workings Kirby won't reveal, is calculated for her body, which means she can't gain or lose more than a few pounds. She relies on her aerialist background.
"Being detail-oriented and being a creature of habit is really essential in this line of work. Consistency is key and every flight is a little bit different," she said.
"Sometimes I'll come out of the barrel and I'll realize, 'I've got a little more rotation than is ideal' and I have to decide in a split second how am I going to stop my rotation so I don't over rotate."
Though her time in the air is brief, Kirby loves to see young women's stunned faces as she zooms through the air, a missile in a sparkly silver outfit.
"I'm not saying that little girls should necessarily watch me and want to do exactly what I do, but I hope that some of them can see my performance and say, 'That's something I didn't realize girls could do,'" she said. For me, that's the most important thing: empower someone to believe in themselves."
Mark Kennedy is at http://twitter.com/KennedyTwits