NASA says a retired solar imaging spacecraft is predicted by the Defense Department to reenter the Earth’s atmosphere Wednesday night and some of it will survive to strike Earth.

“The risk of harm coming to anyone on Earth is low – approximately 1 in 2,467,” NASA said Monday afternoon. The Department of Defense estimates the 660-pound spacecraft will reenter the atmosphere at approximately 8:30 p.m. CDT Wednesday “with an uncertainty of +/- 16 hours.”

The craft named the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) was launched to explore the basic physics of particle acceleration and explosive energy releases in solar flares, NASA said. It was launched in 2002.

The spacecraft data “provided vital clues about solar flares and their associated coronal mass ejections,” NASA this week. “These events release the energy equivalent of billions of megatons of TNT into the solar atmosphere within minutes and can have effects on Earth, including the disruption of electrical systems.”

RHESSI recorded more than 100,000 X-ray events while it functioned and that work allowed scientists to study the energetic particles in solar flares by following the flares frequency, location and movement. RHESSI also stepped outside its primary mission to help scientists improve their measurements of the sun’s shape.

NASA and the Department of Defense will continue to monitor reentry and update predictions.