At launch, the fragile balloon requires low level winds before it can be filled with helium, Professor Ravi Sood, director of the balloon launch facility in Alice Springs told The Associated Press. The balloon is made of a material as thin as plastic food wrap and expands to the size of a football stadium when floated. Sood said winds were too high Monday, but scientists will check conditions each night until a launch is possible.

"If the winds are right we'll go tomorrow morning [Tuesday], and if not tomorrow then Wednesday or Thursday or Friday," Sood said.

The balloon must be launched by February 15, before seasonal changes alter wind patterns, he said.

"I'm sure we'll get it away. Alice Springs has a good record for these launches,'' Sood said.

The Ultra-Long Duration Balloon (ULDB) is the largest single-cell, fully sealed balloon ever flown, with a fully inflated diameter of 193 feet (58.5 meters) and height of 115 feet (35 meters). Once launched, the balloon will fly around the world at an altitude of 20 miles (35 kilometers), almost scraping the edge of space.

The flight is largely for demonstration purposes, but it will also collect data for a cosmic radiation experiment, the National Aeronautics and Space Administration said. If all goes to plan on this flight, the balloon will tackle missions up to 100 days' duration to study the Sun and search for new planets.