After the LINK robot’s failure, NASA’s Swift telescope is living out its final weeks

The facts

On 25 September 2026, the LINK satellite built by US company Katalyst Space left orbit after 85 days in space, according to the press release the company published the same day. Its mission, funded by NASA to the tune of $30 million, was to dock with the Neil Gehrels Swift Observatory and then raise its orbit, which is dropping under the effect of atmospheric friction. The capture was never attempted.

LINK was launched on 3 July by a Pegasus XL rocket, released at an altitude of about 12,000 metres by the Stargazer carrier aircraft from Kwajalein Atoll. During commissioning, it lost attitude control and began to spin: by late July, two of its three reaction wheels were out of service, following a failure in its electrical system, according to Katalyst. Engineers brought its spin down from 9 to 1.47 degrees per second, but attitude control with thrusters used up the propellant that was meant for the capture.

On 19 August, NASA announced that LINK would not capture Swift. The robot then approached to within 12-15 km of the telescope, without going any closer, to take images of it, and tested the control of its three robotic arms, Katalyst says.

Twenty-one years of gamma-ray bursts

Swift was launched on 20 November 2004 by a Delta II into an orbit at an altitude of about 600 km, inclined at 20.6° to the equator. Designed for a two-year mission, it carried out twenty-one years of observations before its orbit began to decay rapidly, NASA points out. Its three instruments work as a relay: the Burst Alert Telescope (BAT, 15 to 150 keV), which covers 16% of the sky at once, spots gamma-ray bursts; the X-ray Telescope (XRT, 0.2 to 10 keV) and the Ultraviolet/Optical Telescope (UVOT) then swing towards the source to follow its afterglow.

By 2015, Swift had already detected more than a thousand gamma-ray bursts, Futura points out. Its strength lies in this automatic chain of events: as soon as a burst is spotted, it points its X-ray and ultraviolet/optical telescopes at it.

An orbit eaten away by the Sun

The problem has been known since January 2025: NASA’s forecasts then predicted re-entry as early as summer 2026, as the peak of solar activity was expanding the upper atmosphere and increasing drag. To buy time, in December 2025 the team replaced about 25% of its science targets with orientations that limit friction, then switched entirely to this mode in February 2026, turning off XRT and UVOT. BAT was paused in April.

NASA opted for a commercial solution: two concept studies in August 2025, then the September 2025 contract. The Pegasus XL was selected in November 2025 because a launch from Kwajalein Atoll, in the Marshall Islands, would place LINK directly into Swift’s orbit, which is only slightly inclined (20.6°) and close to the equator. The robot, weighing about 400 kg and standing 1.8 m tall, went through vibration and thermal vacuum testing at Goddard, in the Space Environment Simulator, the same chamber Swift had used more than twenty years earlier.

What the two partners say

Speaking to the US National Academies’ Committee on Astronomy and Astrophysics on 23 September, Kieran Wilson (Katalyst) attributed the failure to an unresponsive valve in the reaction control system (RCS), followed by the failure of a power circuit switch; in his view, the loss of the reaction wheels accounts for most of why the rendezvous was impossible, SpacePolicyOnline reports. John Von Eepoel, deputy project manager at Goddard, praised the “acceptance of taking a huge risk” at every level of the organisation.

NASA Administrator Jared Isaacman had summed up the situation in August: this is “not the outcome we were working toward”, but it “does not change why this mission was worth attempting”. Katalyst CEO Ghonhee Lee focuses on the timescale: less than a year from concept to commissioning of what he presents as the first commercial space robot. The company says it designed, built, tested and launched LINK in nine months.

What remains to be confirmed

The date of Swift’s re-entry remains uncertain. On 25 September, NASA placed it at an altitude of about 325 km and estimated that it would cross the 300 km threshold, below which operations become difficult and science observations will probably cease, “sometime in early to mid-October”. In August, NASA said it was continuing to study other options for extending Swift’s life, without giving details.

Why it matters

In the meantime, Swift has chosen to keep observing. XRT and UVOT were switched back on on 26 August; BAT detected gamma rays again on 18 September, and automatic slewing towards bursts resumed on 21 September. In early September, scientists estimated that the 300 km threshold would be reached within one to two months, GNT reported. The end of Swift will deprive astronomers of a detector that watches 16% of the sky at once and immediately points its telescopes at each burst. LINK’s failure, for its part, leaves a rare body of lessons learned: those of a commercial attempt at in-orbit servicing carried out from start to finish in less than a year.

Archive note

• Swift was launched on 20 November 2004 for a planned two-year mission.
• NASA’s $30 million contract with Katalyst Space dates from September 2025.
• LINK spent 85 days in orbit, from 3 July to 25 September 2026.