Students in Bill Wiley’s science elective at the Potomac School in McLean, VA signed up for a challenge: photograph the curvature of Earth for $200 or less. Thirteen 7th and 8th graders met every other week for a year, doing the necessary research and project design in preparation for the launch. They purchased and programmed a digital camera to shoot three photos and ten seconds of video every minute. They intalled cold-resistant lithium batteries in the camera and a GPS-enabled cellphone running Instamapper, added chemically-powered handwarmers to keep the electronics warm in minus 70 degree Fahrenheit temperatures, fit them into a $6 styrofoam cooler, and rigged the cooler up to a weather balloon that would carry it 20 miles into the stratosphere, with a parachute to bring it down. The launch on June 5 went off perfectly. There was one hitch on the descent – Google satellite images showed the cooler in a field a four hour drive from where their calculations had shown it would land. One of the students had his father’s iPad along and used that to connect via the cellphone networks to locate the cooler. View photos of the ascent and descent on the Potomac School website. Full story here and a Washington Post perspective here.