Rockets blasted off Tuesday from Piner Olivet Charter School as seventh and eighth grade students put math and science skills into action.

Throughout the morning, students gathered on a grassy field and on the playground as teachers worked with them to send their rockets — plastic soda bottles altered into flying machines — into the bright blue sky.

"This is the fun part," said teacher Rob Pitchford. He was was helping student use a bicycle pump to pressurize the water-filled plastic rockets before take off.

The rocketry program includes research into Newton's laws of motion, Pitchford said. Students also research scientists and make measuring tools to determine the speed and height of their rockets' flight.

Some sailed so high and straight they nearly disappeared from view. Those traveled about 300 meters (nearly 1,000 feet), said Pitchford.

Others soared in twisting, curving flights.

The trick of the perfect aerodynamics was "nice even fins," said Pitchford.

The fins were triangles of cardboard, "duct tape and lots of glue," attached to beverage containers, said seventh grade student Haley Jorgenson.

"Rocket Day" is an annual program at the west Santa Rosa school held in the days before the winter holiday break. That's when students typically are full of excitement for the pending holiday and school break.

"It helps focus their energy in a different way," said principal Diana Drew-Ingham.