A high-tech, high-altitude balloon launched by Cornell graduate students has nabbed world records for size and altitude among amateur ballooners.

The feats, recorded by the world Amateur Radio High Altitude Ballooning records database, reflect the results of an early March launch by Project Blue Horizon (PBH), a Cornell systems engineering graduate student project team. The students are all early-career engineers at Lockheed Martin in Owego and are part of the company's Engineering Leadership Development Program.

The students' balloon reached a maximum altitude of 135,030 feet, beating the previous record of 130,903 feet. The balloon's fully expanded volume reached 141,000 cubic feet, shattering the previous record of 126,000 cubic feet. The 1.5-pound payload helped the students record such data as latitude, longitude and ascent rate.

PBH is a multiyear project to design, construct and launch an amateur balloon with the aim of surpassing distance, duration and altitude records.

The students used a zero-pressure balloon manufactured by Raven Industries. The balloon is designed to vent helium when it reaches a certain altitude, allowing it to stabilize and float. In 2008, a previous generation of PBH students broke the altitude record, then 125,000 feet, using a more traditional latex balloon.

"One of the benefits of amateur ballooning is it's a cost-effective, quick way to collect data at near-space altitudes," said Matt Lewis, PBH project leader.

After their record-breaking flight March 4, the students also launched another mission April 2 with a group of Broome County high school students as part of an outreach program. Later in April, they'll launch a final balloon in which they'll attempt to break additional records in distance and duration.