What useful things can be shot into the stratosphere? Budding scientists and engineers are being invited to figure that out. Tomorrow is the deadline for the annual BalloonSat High Altitude Flight competition. U.S. high school students propose science experiments that are launched high above the earth, using weather balloons as satellites.

Projects have included light and temperature sensors, cosmic ray detection, 3-D photography and video image transmission, and even upper-atmospheric exposure on rubber bands, seeds, and mold. A panel of NASA scientists and engineers will select eight finalists to design and construct their projects.

Then mark your calendars for May 18-20, 2011, to watch the Flight Days competition online. On those dates, the winning projects will be launched near Cleveland, Ohio, almost 100,000 feet into Earth’s upper atmosphere.

On left, marshmallow recovered from the stratosphere

That height—the stratosphere—is much higher than commercial aircraft fly, and the atmospheric conditions are similar to those on Mars. Just take a look at what happened to a marshmallow shot into the stratosphere! To learn more, visit the BalloonSat website, view photos or the webcast of last year’s competition, or read about NASA’s Research and Operations Facilities. Interested in other science and technology challenges? Visit Challenge.gov.