Mission officially concluded

NASA has officially ended the mission of the Swift space telescope after more than 21 years of service. The telescope will soon burn up in the atmosphere, leaving behind an immense scientific legacy.

Atmospheric drag and solar activity

All satellites in low orbit experience atmospheric drag, a phenomenon exacerbated by recent solar activity, which gradually caused Swift to lose altitude. Although its end was inevitable, NASA initiated an unprecedented mission to save it, in partnership with the startup Katalyst.

Final observations and safety mode

However, this effort failed, allowing the telescope to continue observations before its destruction. Swift is in standby mode, allowing it to point its instruments toward hundreds of targets, from remnants of stellar explosions to giant black holes in distant galaxies, as well as comets in our solar system.

End of observational capacity

But on October 20, the telescope fell to an altitude of 275 kilometers. At that height, the remaining air slows it down too much for it to keep its instruments aimed at a target. The device can simply no longer observe the universe: it entered safety mode on the same day, that is, a standby state that protects the satellite when it can no longer function normally.

Final command for reentry

The team responsible for operations, at the Pennsylvania State University, thus sent it a final command to end its activity and prepare it for atmospheric reentry, which should occur within a few weeks.

Swift's original purpose

Launched on November 20, 2004, Swift was designed to track the most powerful explosions in the universe. As explained by S. Bradley Cenko, the mission's principal investigator, it was supposed to "detect and locate gamma-ray bursts" and then transmit their positions to other telescopes before photographing them before their light faded.

Early success and scientific impact

This responsiveness paid off as early as May 2005, when Swift turned toward a burst that lasted only 0.03 seconds, it then captured 11 X-ray photons from its residual light, a first for such a brief explosion. This result confirmed that these flashes likely originate from the fusion of two neutron stars, celestial bodies as heavy as the Sun but much smaller.

Swift's scientific achievements

Over the years, the telescope has detected more than 2,000 gamma-ray bursts and observed more than 1,400 supernovas. It has also seen stars torn apart by black holes and conducted a full-sky survey in X-rays. Its data has fed approximately 7,000 scientific publications.

Legacy and future use

These 22 years of measurements form a public archive of about 12 terabytes, including more than 1.5 million visible and ultraviolet light images, equivalent to 600 high-definition movies. A database that should fuel discoveries for decades. Indeed, NASA is already exploring how to regain this responsiveness with its existing telescopes and new missions.