Student balloon crosses the continent.
If you glanced at just the right place in the sky last June, you might have spotted a record-breaking dot.
OK, perhaps that’s doubtful; the dot in question — a high-altitude balloon launched by the Stanford Student Space Initiative — was cruising along at 45,000 feet as it passed over North America.
The undergraduates worked for a year and a half engineering a satellite-controlled flight system for latex balloons (not unlike the common birthday variety). The resulting technology is ValBal, short for “Valve-Ballast,” explains Kirill Safin, ’18, leader of the group’s balloons team. To keep the balloon from ascending too high and popping, a mechanical valve in the balloon stem releases helium, and a ballast system drops tiny weights — biodegradable airsoft pellets “like the kind you find in BB guns” — to maintain a constant altitude. The team released version 5.1 from Modesto, Calif., and tracked it as it drifted 3,565 miles over the continent, breaking a world time record with its 70-hour flight.
Safin thinks the balloon could go farther in the right conditions; unfortunately, this one crashed in the Atlantic. Because the satellite beacon kept transmitting GPS coordinates, he speculates that “it just happened to float. So we’d like to get it back, but it’s not the end of the world if we don’t.” •