The Herschel Space Telescope is fully operational again after engineers brought a damaged instrument back online.
The observatory's HiFi spectrometer was turned off three months into its mission because of an anomaly that was probably triggered by space radiation.
The Dutch-led consortium that operates HiFi has now switched the instrument across to reserve electronics.
The European Space Agency (ESA) telescope was launched last May. The observatory is positioned 1.5 million km from Earth.
Its quest is to study how stars and galaxies form, and how they evolve through cosmic time.
The Herschel mission is expected to last about three years before a helium superfluid that drives its cooling system boils away and the instruments detectors will lose their sensitivity.
