STS-125, or HST-SM4 (Hubble Space Telescope Servicing Mission 4), was the fifth and final space shuttle mission to the Hubble Space Telescope (HST). Space Shuttle Atlantis carried two new instruments to the Hubble Space Telescope, the Cosmic Origins Spectrograph and the Wide Field Camera 3. The mission also replaced a Fine Guidance Sensor, six gyroscopes, and two battery unit modules to allow the telescope to continue to function at least through 2014. The crew also installed new thermal blanket insulating panels to provide improved thermal protection, and a soft-capture mechanism that would aid in the safe de-orbiting of the telescope by an unmanned spacecraft at the end of its operational lifespan.