NASA's Neil Gehrels Swift Observatory is expected to meet a fiery end early Wednesday morning, nearly 22 years after it launched to study the most powerful explosions in the universe.

While most of the 3,200-pound spacecraft is expected to burn up as it blazes through the thick inner band of Earth's atmosphere, NASA predicts some pieces of the vehicle will hit the ground.

"The risk of harm coming to anyone on Earth is unlikely, approximately 1 in 2,100," NASA said in a statement Monday.