In late December near McMurdo Station in Antarctica, the National Science Foundation (NSF) and the National Aeronautics and Space Administration (NASA) flight-tested a large, pumpkin-shaped, thin-skinned balloon that will someday carry science experiments to the brink of space.  

According to an NSF press release, this 7 million cubic foot balloon is the largest single-cell, super-pressure balloon ever flown. (“Super pressure” means there is a higher pressure inside the balloon than outside.) When development is completed, NASA will have a 22 million cubic foot balloon that can carry a one-ton instrument to an altitude of just over 110,000 feet — three to four times higher than passenger planes fly.

The balloon will play an important role in providing inexpensive access to near-space. With continued development, similar balloons are expected to fly for months at a time. David Pierce, chief of the balloon program office at NASA Goddard Space Flight Center in Virginia, says, “The test flight has demonstrated that 100-day flights of large, heavy payloads is a realistic goal.”

Unique atmospheric circulation over Antarctica during the austral summer (November – March) allows scientists to launch balloons from a site near McMurdo Station and recover them from nearly the same spot weeks later. Constant daylight means no day-to-night temperature fluctuations on the balloon, which helps it stay at a nearly constant altitude.

The test balloon is made of lightweight polyethylene film about the thickness of plastic food wrap. (Find more information, pictures, and a kids’ page about the pumpkin balloon at http://sites.wff.nasa.gov/code820/uldb.html.) Among the advantages of balloon-powered space research are the facts that it costs less than satellite-based research and the scientific instruments can be retrieved and used again.