NASA is inviting student teams to design and build experiments the agency will fly into the stratosphere, a near-space environment, more than 100,000 feet above the Earth.

NASA's second annual Balloonsat High-Altitude Flight competition is open to student teams in ninth to 12th grades from the United States and its territories.

Each team of four or more students must submit an experiment proposal to NASA's Glenn Research Center in Cleveland by Feb. 11. Student teams may propose experiments on a wide range of topics, from bacteria studies to weather observations.

A panel of NASA engineers and scientists will evaluate the submissions based on mission objectives, technical planning and team organization. The top eight proposals will be announced on March 4.

The top four teams will receive up to $1,000 to develop their flight experiments and travel to Glenn Research Center May 18-20.

During their visit, they will have an opportunity to tour the center, watch as NASA helium weather balloons carry their experiments to the edge of space, recover the experiments and present their results at Glenn's Balloonsat Symposium.

The other four teams also will receive up to $1,000 to develop their flight experiments and will participate via the Internet when NASA scientists and engineers launch and recover their payloads during the week of May 23.