The Neil Gehrels Swift Observatory, a NASA satellite launched in 2004, is expected to make an uncontrolled re-entry into Earth’s atmosphere on Wednesday and will burn up during descent. The observatory, which has operated far beyond its planned lifetime, is no longer able to steer or carry out observations.
End of service after two decades
Designed to operate for approximately two years, the spacecraft instead provided about two decades of observations of high-energy phenomena, including gamma-ray bursts — the most powerful explosions known in the cosmos. Swift carried three telescopes that allowed it to detect bursts and rapidly point its instruments to study their afterglows across multiple wavelengths.
Failed recovery effort
In recent weeks and months mission teams sought to regain control of the satellite but were unable to restore steering and observing capabilities. Following that unsuccessful recovery effort, the re-entry will be uncontrolled, meaning the exact time and location of atmospheric entry cannot be precisely predicted in advance.
Legacy and monitoring
Despite the abrupt end to the mission, Swift leaves a long record of observations that informed studies of stellar explosions, black holes and other transient events. Agencies that track re-entering objects monitor the satellite’s descent to refine timing and impact predictions; officials expect the spacecraft to burn up as it passes through the atmosphere.
The observatory is named for Neil Gehrels, a prominent astrophysicist who played a leading role in missions to study transient and high-energy astronomical events. Its extended lifetime and the body of data it amassed have been widely cited in research on cosmic explosions and transient astrophysical phenomena.