NASA's Swift Space Telescope Heading for Uncontrolled Reentry After Rescue Fails
Written by AI from space.com's report. Not checked by a person.
NASA's Neil Gehrels Swift Observatory is expected to reenter Earth's atmosphere in the coming days after a robotic rescue mission failed to boost it to a higher orbit. Most of the roughly 3,300-pound spacecraft is expected to burn up, with small dense fragments potentially reaching a band within about 21 degrees of the equator.
NASA's Neil Gehrels Swift Observatory, launched in November 2004 to study gamma-ray bursts and other cosmic events, is falling back to Earth after a failed robotic rescue mission. The spacecraft carries three scientific instruments: a Burst Alert Telescope, an X-Ray Telescope, and an Ultraviolet/Optical Telescope.
On October 20, NASA reported that Swift's orbit had decayed to 171 miles (275 kilometers) and that the roughly 3,300-pound (1,500-kilogram) observatory could no longer compensate for increased atmospheric drag. The spacecraft entered safe mode, and its operations team at Pennsylvania State University sent a command that effectively ended its operations. A robotic rescue mission aimed at boosting Swift to a higher orbit failed, leaving the telescope on course for an uncontrolled reentry expected within the next few days. The exact timing and landing location remain unknown.
Swift's orbit passes over a band within about 21 degrees of the equator — a zone that is mostly ocean but also crosses populated parts of Africa, South and Southeast Asia, and Latin America. Most of the spacecraft is expected to burn up, with solar panels and antennas tearing off first and the main body breaking apart at around 78 kilometers altitude. The components most likely to survive are its six heavy reaction wheels — spinning flywheels used to aim the telescope — along with tougher parts made from heat-resistant materials such as titanium, steel, and glass. NASA and reentry analysts describe the casualty risk as very small.
The event has renewed debate about uncontrolled reentries more broadly, with experts noting there are now ten times more objects reentering per year than there were five years ago.
