Atlantis STS125 or the final visit to Hubble Space Telescope

Right now, I am watching the launch of Atlantis Shuttle STS-125) in live on NASA TV. I rarely watch the launch of the shuttles mostly for lack of time and information about the goals of the mission, thus interest. This launch isĀ  extremely important for astronomers since it is the 4th service mission (SM4) for the Hubble Space Telescope. It is also the final visit to this space telescope.