NASA said on September 25 that its Neil Gehrels Swift Observatory has resumed using all three science instruments and can again turn automatically toward sudden gamma-ray flashes. The restored capability lets the spacecraft identify an outburst with its Burst Alert Telescope and promptly study it in ultraviolet, visible and X-ray light. NASA cautioned that the observatory is still descending and may lose the ability to carry out science observations in early to mid-October.
The Burst Alert Telescope, which can view about 16% of the sky at once, had been switched off in April to save power. That allowed controllers to orient Swift's solar panels in a way that reduced atmospheric drag while a commercial spacecraft prepared to raise its orbit. NASA scaled back that boost mission after problems with the servicing spacecraft. Swift's ultraviolet and X-ray telescopes returned to data collection in August, according to the agency.
NASA said the team confirmed on September 18 that the gamma-ray instrument was calibrated and detecting radiation. Controllers restored automatic pointing on September 21. When the detector spots a gamma-ray burst, Swift can interrupt the observation plan sent from Penn State in University Park and aim its other two telescopes at the event. Such rapid follow-up is central to the observatory's study of fleeting, high-energy phenomena.
The return comes after months of restrictions intended to slow the spacecraft's fall. Starting in December 2025, the science team replaced roughly a quarter of planned targets with directions that produced less drag; by February, it had adopted that approach for all targets and stopped automatic responses to bursts. NASA's latest report says Swift is now about 200 miles, or 325 kilometers, above Earth and is sinking faster again as normal science operations resume.
NASA places a practical threshold near 185 miles, or 300 kilometers, below which operations become more difficult and science observations are likely to stop. Its current estimate puts Swift at that altitude in early to mid-October. The revived alert system therefore offers astronomers a limited period to capture new bursts while mission controllers continue monitoring the orbit.
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