U.S. researchers are developing a high-altitude, helium-filled aircraft that could hover over the same spot for up to a year.

Researchers at Purdue University said the blimp, which uses solar cells for power, could have applications in surveillance, homeland security, missile defense and weather forecasting.

Part of the concept is an aerodynamic design and control system that will help keep the airship steady amid high winds. Computer simulations have shown how the craft would perform given specific design characteristics, they said.

“The concept is to have an airship that flies above 65,000 feet and is geostationary, which means it stays in the same position over the Earth,” said project leader Oleg Wasynczuk, a professor of electrical and computer engineering.

The airship is intended to fly well above commercial aircraft, which cruise as high as 40,000 feet, and conventional blimps, which reach only around 5,000 feet.

The researchers said the craft would have better surveillance capabilities than satellites because it would be closer to the ground. It also could hover over one location anywhere in the world, whereas satellites are geostationary only over the equator.