During mission STS-125, astronauts installed two new instruments on the telescope. One was the Cosmic Origins Spectrograph, which allowed Hubble to observe faint objects in the cosmos in ultraviolet light. This would help researchers study the formation of galaxies and other large-scale structures in the universe.
The second instrument was the Wide Field Camera 3, which replaced the old Wide Field and Planetary Camera 2 that was installed during the first servicing mission in 1993. This new camera could observe the universe in visible, near-infrared and near-ultraviolet light with a higher resolution and larger field of view than any of Hubble’s older instruments.