Replacing the Instrument: Astronauts carefully remove the Corrective Optics Space Telescope Axial Replacement (COSTAR) to make room for the Cosmic Origins Seismograph (COS). NASA
From Popsci.com:
The latest -- and final -- upgrade to Hubble will study the origins of the universe.
When astronauts pay a final visit to the Hubble Space Telescope next week, one upgrade in particular will illuminate the darkness like never before -- and it involves taking out the corrective lenses that let Hubble see clearly for the past decade and a half.
The Cosmic Origins Spectrograph, a fridge-sized instrument that will be installed in place of Hubble's original corrective optics set, will help astronomers learn more about the large-scale structure of the universe. Scientists hope it will help explain how stars and galaxies evolved; how the building blocks of life, like carbon and iron, came to be; how matter is distributed in the universe; and, well, what the matter is.
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