Launched in 2004, Swift initially orbited 370 miles above Earth. Over time, its orbit steadily descended to its current altitude of just 210 miles. In this denser air, atmospheric drag is rapidly pulling the telescope down. Within a few months, friction will drag Swift into the thicker atmosphere and rip it apart.

That is, unless a daring robotic rescue can pull off a never-before-tried feat: catching Swift and nudging it back to safety. That rescue spacecraft, named Link, successfully launched on July 3.

Replacing Swift would take years and cost hundreds of millions of dollars. Instead, NASA wagered $30 million on Katalyst Space Technologies, an Arizona startup. Katalyst built Link in just nine months — a blistering pace compared to typical multi-year space programs.

To save the telescope, standard engineering luxuries were bypassed. NASA gave Katalyst total design flexibility with only two core mandates: boost the telescope's orbit, and do not crash into or damage it.

"The risk of us losing Swift — if we hadn’t done this — was 100 per cent," said Shawn Domagal-Goldman, NASA’s astrophysics division director. "From a financial and management standpoint, this made sense."

Katalyst’s CEO, Ghonhee Lee, founded the company with a vision of deploying space robots to repair and refuel satellites. The company was also fortunate to secure a discounted, leftover rocket; standard launch vehicles like SpaceX's Falcon 9 would have consumed the mission's entire $30 million budget.

Swift is crucial for studying gamma-ray bursts, the highest-energy light in the cosmos. These brief, violent flashes tell stories about moments of extreme cosmic violence, like the explosive deaths of massive stars and collisions between ultradense neutron stars.

When another telescope spots a burst, Swift lives up to its name by quickly swivelling to measure the high-energy light as it fades away. NASA originally planned for a two-year mission, leaving no contingency plans for a future orbital boost a couple of decades later.

Swift’s fall was heavily accelerated by the sun's 11-year sunspot cycle. Peak solar activity in late 2024 shot out intense solar flares that heated Earth's atmosphere and puffed it outward, dramatically increasing orbital drag. Faced with losing the telescope this year, NASA scrambled to find private companies with ready-to-deploy technologies.

To buy time, Swift stopped regular observations this year to perform manoeuvres to slow its fall. The rescue operation will now unfold in distinct phases. Controllers will spend two weeks verifying Link's systems, followed by a month and a half to approach and grab Swift. Finally, Link will gradually propel the telescope 100 miles higher over two months, enough of a boost to keep Swift operational for another decade.

The New York Times