A unique NASA satellite is falling out of orbit—this team is trying to rescue it - Ars Technica

BROOMFIELD, Colorado—One of NASA’s oldest astronomy missions, the Neil Gehrels Swift Observatory, has been out of action for more than a month as scientists await the arrival of a pioneering robotic rescue mission.

The 21-year-old spacecraft is falling out of orbit, and NASA officials believe it’s worth saving—for the right price. Swift is not a flagship astronomy mission like Hubble or Webb, so there’s no talk of sending astronauts or spending hundreds of millions of dollars on a rescue expedition. Hubble was upgraded by five space shuttle missions, and billionaire and commercial astronaut Jared Isaacman—now NASA’s administrator— proposed a privately funded mission to service Hubble in 2022, but the agency rejected the idea.

Swift may be a more suitable target for a first-of-a-kind commercial rescue mission. It has cost roughly $500 million (adjusted for inflation) to build, launch, and operate, but it is significantly less expensive than Hubble, so the consequences of a botched rescue would be far less severe. Last September, NASA awarded a company named Katalyst Space Technologies a $30 million contract to rapidly build and launch a commercial satellite to stabilize Swift’s orbit and extend its mission.

The Swift observatory is flying in low-Earth orbit, where the outermost layers of the atmosphere still exert some aerodynamic influence on satellites. The spacecraft launched in November 2004 on a mission to detect gamma-ray bursts, the most powerful explosions in the known Universe. Despite its age, astrophysicists still rely on Swift’s multi-wavelength instruments to identify and locate gamma-ray bursts for follow-up observations by other observatories.

Gamma-ray bursts happen without warning, when massive stars die and form black holes or during mergers of neutron stars and black holes. Their afterglow can last from a few seconds to up to a few hours. Scientists need satellites like Swift to find and study them. One of Swift’s unique abilities is to quickly turn to point toward gamma-ray sources before they fade, a proficiency that gave the mission its name. Until last month, the mission remained operational and scientifically productive, and there is no other US satellite that fully replicates Swift’s capabilities.

But the Swift spacecraft will surely crash back to Earth, likely before the end of this year, without a reboost. That’s where Katalyst comes in. The company’s robotic servicing spacecraft, named Link, will attempt to rendezvous and dock with the Swift satellite, then raise its altitude to give the observatory a new lease on life.

That is, if everything goes according to plan.

There are a few things you should know about this venture. First, Swift was never designed to be captured or reboosted in orbit. Second, this mission is the first time Katalyst will attempt to dock with another satellite in space. And third, NASA gave Katalyst a daunting timetable of just nine months to build, test, and launch the rescue mission before Swift’s altitude falls too low for a safe rendezvous.

“This is really technically ambitious,” said Ghonhee Lee, founder and CEO of Katalyst.

Launch is scheduled for June 1, and there’s little margin for error. By late summer or early fall, Swift will slip below 200 miles (320 kilometers), too low for Katalyst to have confidence in controlling its spacecraft. “It’s a lot of drag with two big spacecraft docking together, ” Lee said. “Originally, we thought we had more time.”

NASA’s goals are twofold: first, demonstrate an important capability for the future of space exploration, and second, save Swift from a fiery demise and continue its scientific observations.

“We realized that you can’t get 100 percent guaranteed success on this,” Lee said.

When Ars visited Katalyst in late February, technicians were heads-down at work stations, soldering parts, assembling solar panels, and preparing components for environmental testing. For a traditional government space mission, a project might be at this stage of manufacturing years before reaching the launch pad.

“This is not quite as mature as you would expect,” one company official said. “Keep in mind that we started this whole thing about five months ago, so we are making great progress by those standards.”