For two decades, when the high-energy universe called, NASA’s Neil Gehrels Swift Observatory has answered. But now, the spacecraft’s science tenure is ending, just when its skills might be more valuable than ever. The Swift spacecraft is falling uncontrollably, destined to burn up in Earth’s atmosphere in just a few days.

The telescope launched in 2004, tailored to reveal the secrets of gamma-ray bursts . These outbursts are the most powerful kind scientists have ever seen, but they often faded before earlier telescopes could respond. Swift took its name from its ability to jump to work when a flash went off. That talent both illuminated these elusive bursts and made the observatory a cornerstone of modern astronomy for far longer than scientists ever dreamed.

“This was designed to be a two-year mission,” says astrophysicist Brad Cenko of NASA’s Goddard Space Flight Center in Greenbelt, Md. “We’re coming up on year 22.…