joshuark shares a report from Wired: After 22 years in orbit and a failed rescue mission this summer, it is highly likely that the Neil Gehrels Swift Observatory will crash into Earth sometime next week. It is not known where on the planet the spacecraft -- which is roughly as big as a large elevator -- will fall. Despite its size, experts say the risk to the public is relatively low. The observatory was designed to operate for a few years in low Earth orbit, but it far exceeded its expected lifespan, helping to make many important discoveries about the evolution of the cosmos, including the study of supernovas and the destruction of stars by black holes. However, in 2024, increased solar activity heated and expanded the upper layers of Earth's atmosphere, increasing the drag on the satellite and accelerating its descent. Without a propulsion system capable of correcting its orbit, its days were numbered. The U.S. Space Force now expects Swift to reenter Earth's atmosphere around November 6. Most of the spacecraft is expected to burn up, although some components could survive and reach the ground (but most likely the ocean). "The most likely survivors are its six heavy reaction wheels, the spinning flywheels it used to aim itself, along with tougher telescope parts such as lenses and mirrors," Dean Sladen, a quality manager and aerospace engineer at Accu Components, told Space.com. "Only a handful of small, scorched fragments are expected to make it down -- nothing recognizable as a telescope." "NASA's own orbital debris requirements state that the risk of human casualty from surviving debris shall not exceed one in 10,000, so it is highly likely this work has been completed but not published," Sladen said regarding the risk assessment. "Personally, I believe it should be published, as NASA has done with previous satellites. The risk is almost certainly very small, but it would give people a clear, factual picture rather than guesswork."

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