NASA is tracking the uncontrolled re-entry of its decommissioned Swift Observatory, a 3,200-pound space telescope that is set to fall back to Earth on Wednesday. Some components of the spacecraft are expected to survive the fiery plunge through the atmosphere.
Launched in 2004, the Swift Observatory was designed for a two-year mission to study gamma-ray bursts and other powerful cosmic events. After 21 years of operations, its low Earth orbit began to decay rapidly due to increased solar activity.
NASA anticipates the telescope will make an uncontrolled descent around 3:30 a.m. ET, with an 11-hour uncertainty window. "Re-entry locations of any surviving components can vary from hemisphere to hemisphere and depend on when it re-enters," NASA stated.
A tracking map shows Swift's orbital paths crossing a broad belt around the equator, indicating that any surviving debris could land over parts of Central and South America, Africa, southern Asia, and northern Australia, as well as large ocean areas. The United States and Europe are considered to be outside the potential impact zone.
The re-entry follows a failed rescue attempt in August, during which NASA spent $30 million to send another spacecraft, named Link, to attempt to boost Swift into a higher orbit. However, Link experienced uncontrollable spinning shortly after its July liftoff, and subsequent issues with its pointing and positioning led to the cancellation of the rescue.
Despite the failed rescue, Swift continued its scientific operations, discovering additional gamma-ray bursts and other high-energy events. By late October, however, the telescope's orbit was too low for stable observations, and its systems were shut down.
During its extended mission, Swift recorded over 2,000 gamma-ray bursts and 1,400 exploding stars, along with observations of comets, asteroids, and black holes. Its ability to quickly swivel towards celestial events made it a crucial early warning system for other observatories like the Hubble and Webb space telescopes.
"We’ve known this day would come since before Swift was launched," said John Nousek, an astronomer at Pennsylvania State University involved in the mission. "At least in low-Earth orbit, what goes up must come down. And that end is catastrophic."
Scientists are now working to determine how to fill the observational gap left by Swift's deactivation. "Our fervent hope is that the lessons learned by the successes of Swift can be applied to new generations of space missions to accelerate our discoveries about the universe," Nousek added.