(Neil Gehrels Swift Observatory, Swift Gamma-Ray Burst Mission, Explorer 84)
(satellite for studying gamma-ray bursts)
Swift (or Neil Gehrels Swift Observatory, previously the
Swift Gamma-ray Burst Mission)
is a NASAMedium-class Explorer Program (MIDEX) space observatory specifically for
detecting gamma-ray bursts (GRBs) and their afterglow.
Swift was launched in 2004 into low Earth orbit
for a 2-year primary mission and a goal of 5 years' operation.
Its goal was detection of roughly a hundred bursts per year,
and its performance has been close to that.
It is still operating in 2026, but expected to end very soon.
Instruments:
The spacecraft itself is thought to be capable of ten or more years
of additional operation.
However, the spacecraft has undergone significant recent orbital decay
(presumed to be due to high solar activity), and reentry into
Earthatmosphere is predicted before the end of 2026.
NASA contracted a July 2026 space mission (Swift boost mission)
to attempt to enlarge its orbit and thereby extend its life,
but the mission failed.