NASA's Swift Observatory to re-enter Earth's atmosphere-Xinhua - 新华网

LOS ANGELES, Nov. 2 (Xinhua) -- NASA's Neil Gehrels Swift Observatory is expected to re-enter Earth's atmosphere on Wednesday, nearly 22 years after its launch, NASA said in a statement on Monday.

Launched in 2004, Swift was the first-of-its-kind multiwavelength observatory designed to study gamma-ray bursts, some of the universe's most powerful explosions, using its three telescopes.

As of Monday, the U.S. Space Force predicted that the roughly 3,200-pound (1,450-kilogram) spacecraft would re-enter the atmosphere at around 3:30 a.m. Eastern Time (0830 GMT) Wednesday, with an uncertainty window of 11 hours.

NASA expects most of the spacecraft to burn up as it travels through the atmosphere, but some components are expected to survive re-entry.

Depending on the timing of re-entry, any surviving debris could land in areas between 20.6 degrees south and 20.6 degrees north, while the risk of harm to anyone on Earth is very low, estimated at approximately one in 2,100, according to NASA.

NASA had sought to extend Swift's operational life through a commercial spacecraft servicing mission, but the effort was scaled back to technology demonstrations after the servicing spacecraft encountered technical problems and ran low on fuel.

NASA said on Oct. 23 that Swift had ended its science mission as its orbit continued to decay.

Originally designed for a two-year prime mission, Swift went on to operate for more than two decades, serving as a multi-tool for exploring the universe, observing a wide range of light, rapidly pointing at short-lived outbursts, and sending alerts to other facilities to help coordinate follow-up observations, according to NASA. ■