One hundred twenty-one rockets ascended in the air nearby Kline Biology Tower this Saturday, deploying parachutes as they drifted back to the cheering astrophysicists.

Those scientists were not Yale faculty members testing out their latest lab experiment. They were middle school girls participating in the Girls’ Science Investigations, a free program, partially funded by Yale, meant to inspire more girls to develop an interest in science and to narrow the gender disparity in scientific fields.

The event kicked off the first of four full-day science workshops scheduled for the year, covering topics ranging from astrophysics to quantum mechanics to electromagnetics. These highly complicated fields are distilled by Bonnie Fleming, the program’s founder and co-director and a professor of physics at Yale, into accessible and engaging daylong workshops, said Dana Joseph, a high school junior in New Haven and alumna and now volunteer of the program.

“Bonnie does an incredible job of helping people connect intricate topics to things they already understand,” Joseph said. “It’s so important for young girls to know they can do hard stuff, and this is rocket science — it doesn’t get more complicated than that.”

The 121 girls in the program started the day with a series of classes on rocketry, extraterrestrial life and physics. Each girl constructed a two-foot-tall rocket with a parachute in the nose of the rocket and a decorated telescope to watch the rocket.

Kelly Nowak, whose daughters have participated in the program, said she learned about the opportunity when her older daughter’s teacher nominated her for the program. As a patent attorney who uses scientific knowledge on a daily basis, she was excited to introduce her daughters to science, she said.

“We just have to get girls out there and interested in science,” she said. “Programs like this help you do it.”

Nowak added that she wished that the program could take place at times other than Saturday mornings to accommodate girls involved in sports. Her daughter, she added, is passionate about science but struggles to find opportunities to get involved in science that do not conflict with her hockey schedule.

At 12:50 p.m., the girls left Sloane Physics Laboratory and went out into the Science Hill quadrangle to fire the rockets.

“This is scary,” said one sixth-grader in line, watching the row of rockets connected by wires to the control panel. Each participant pressed the launch button for her own rocket.

“It shoots out fiery rainbows,” shouted a girl by her side.

Another speculated that a rocket might lose control, spiral in mid-air and fly into the crowd of sixth-, seventh- and eighth-graders, where it would explode in a fireball. Later in the day, one rocket did sputter out about 30 feet into the air and land near the crowd. There were no injuries, and no fireball appeared.

The more common concern, though, was that the parachutes on the rockets would work too well and the models would float away.

“This is Mission Control, Athena to Pilot: any last words?” asked one girl, bracing herself for the rocket’s risky journey.

“I feel so bad for all the tiny people,” she added. “They are good men, we have to believe in them. They have little tiny families!”

She later renamed Mission Control. It became known as Codename Glitter Crescent.

Durga Thakral ’12 GRD ’20 MED ’20, who has volunteered for the program since 2010, said she was excited to engage with the participants because of their boundless curiosity. She particularly enjoyed delving into complicated topics like quantum mechanics, and answering the creative questions the girls asked.

“When you’re working in the lab and your experiments fail and you’ve had a week of no progress, it’s wonderful to come on a Saturday and share your enthusiasm with young girls,” she said. “It reminds me that science really is exciting and offers so many possibilities.”

Joseph, the alumna and volunteer, echoed Thakral’s statements, saying the program manages to bridge the gap between the exciting mechanics of, for instance, volcanoes and light, and their more technical explanations.

Kate Klemme, a participant in the program, attributed some of her passion for chemistry to Girls’ Science Investigations, which she has attended five times.

“My favorite part of science is chemicals,” said Klemme. “It’s really cool how you can combine two things to make something new.”

The program began in 2007. The next event will be “The Electromagnetic World,” offered on Nov. 14.