As part of their learning experience in a STEM summer camp, students at Southern High School build a trebuchet to launch melons. (Kenneth K. Lam/Baltimore Sun video)

The block of ice was flung so high in the air that some thought it might melt in Thursday's hot summer sun.

Instead, it plopped and then disintegrated in space No. 540 in North County High School's stadium-side parking lot, setting off a raucous cheer from Anne Arundel County STEM (Science, Technology, Engineering and Math) magnet students.

The students had designed the trebuchet that sent the projectile skyward as part of a county program that prepares rising high school students for STEM-related work.

The county's Summer Bridge programs are mandatory instructional sessions for STEM students as they transition from one grade to the next. At North County High in Glen Burnie on Thursday, rising ninth-graders participated in a trebuchet contest called Punkin' Chunkin', which involved hurling projectiles from medieval-style siege engines made mostly of lumber, weights, rope and duct tape.

Competitors included students from North County and South River High, which offer Anne Arundel's STEM high school magnet programs, with each taking turns hurling items that included blocks of ice, fruits, vegetables and clay.

The competition was the culmination of two weeks of work designing the trebuchet — and teams continued making modifications even between throws. Instructors said the competition illustrates for students the engineering design process. The summer program is among many outside-the-classroom projects that reflect Anne Arundel County's approach to STEM course offerings.

School officials said Summer Bridge is an orientation to the Anne Arundel STEM magnet, introducing rising ninth-graders to the demands of the program as well as implementing team-building concepts before they enter high school.

"It gives kids problems that they've never come up with. None have ever built a trebuchet, and they probably fixed 150 problems on this one alone," said Southern High School technology education teacher Keith Brezina, who worked with the South River team.

As he spoke, the team attempted its first throw with a cantaloupe, which was flung the wrong way, landing several feet behind the trebuchet. Students quickly lowered the arm of the device and began more modifications.

"They know to adjust the top pin. The pin on the end adjusts the throw," Brezina said while students made modifications. "They have to tweak it so it gets accurate. That will make it go further."

Indeed, most of their subsequent attempts sailed forward with an arching trajectory.

Brezina said the competition began three years ago, and he likened it to an annual event held in Delaware that has been featured on the Science Channel. He said he hopes to implement a contest throughout the Anne Arundel school system and decided to introduce it to STEM students first.

Students didn't mind braving the 90-degree heat for the competition.

"This has been awesome," said South River High student Chris Kayser of Davidsonville. He said he signed up for the STEM program because he figured it would offer more challenges than traditional high school and added, "It looks good on a college resume."

Ron Smalley, a technology education teacher at Old Mill High School, instructed the North County students working on their trebuchet, making adjustments after the first attempts went virtually nowhere. Once fine-tuned, the contraption hurled objects with a line drive.

"Making it fun for students means keeping them interested," Smalley said. "They said that when they entered the program they thought they would dread it because they thought it was going to be a lot of writing, but with the actual hands-on, they really enjoyed it."

North County ninth-grader Taylor Hayman of Pasadena said she signed up for the STEM courses in hopes of an eventual career in robotics, fueled by a passion for building things.

Taking part in Thursday's competition, Hayman said, "is amazing. I've watched the punkin' chunkin' show on TV and I love to see the pumpkins fly and smash everywhere. The thought of building a trebuchet to do that is just awesome."

In addition to trebuchet building, students in Summer Bridge also take part in such programs as NASA robotics, gaming, information assurance and marine repair.

"When you give kids something they've never done and put it in a competition, that makes it fun without a doubt," said Brezina. "They all want to be No. 1. And as much as I hate to say it, busting up things, for kids, makes it fun."

jburris@baltsun.com