NASA's Swift Observatory Ends Operations: After Sinking to 171 Miles It Entered Safe Mode and Will Re-enter Within Weeks
NASA announced on October 23 that the Neil Gehrels Swift Observatory has concluded operations and is expected to re-enter the atmosphere in the next few weeks. The spacecraft studies gamma-ray bursts, the most powerful explosions in the universe, and other cosmic objects and events.
All satellites in low Earth orbit experience atmospheric drag, NASA said, and recent solar activity increased that effect on Swift, which began to sink rapidly. A high-risk, fast-turnaround servicing mission ended in August without an attempt to boost the observatory.
Swift then restarted science observations, which the team had paused to minimize drag and extend the spacecraft's time in orbit to support the boost mission. Since then, Swift has observed hundreds of science targets, ranging from the remnants of stellar explosions to active supermassive black holes in distant galaxies and comets in our own solar system.
The return to observations increased drag on the spacecraft, and Swift again began to sink rapidly. On October 20, Swift reached 171 miles (275 kilometers), was no longer able to compensate for the increased drag, and entered safe mode. The operations team at Penn State in University Park then sent a command that effectively ended Swift operations to prepare it for re-entry.
NASA said Swift leaves behind a legacy of innovation and a treasure trove of science observations, with further updates to follow on the Swift blog.
Source: GSM · USA (original Chinese edition)
Photo: Neil Gehrels Swift 天文台航天器模型图，NASA E/PO、Sonoma State University/Aurore Simonnet，公共领域（维基共享资源）
