Repairs
• Repair two failed instruments in space, which is the first time such a task is going to be attempted. This will be a test to see if Nasa can do this kind of tasks in future missions to the Moon and Mars. The repairs will require removing 110 (yes, a hundred and ten) little screws. While this seems easy, not only it will take a lot of time in zero mavity, but the screws, like any other floating debris, may become a big problem for the security of the astronauts up there.
• The first instrument to be repaired is the Advanced Camera for Surveys (ACS). It was installed in 2002, and then died after being the most used instrument in Hubble for years.
• Then they have to fix the Space Telescope Imagine Spectrograph (STIS). This is a black hole hunter which also did the first detection and chemical analysis of a planet orbiting another star.
New instruments
• They will install the fanciest, most advanced spectrograph in space: the Cosmic Origin Spectrograph.
• In addition to the COS, they are also going to install the Wield Field Camera 3. This new camera is ten times better than the current instrument, and will let us see into the past of the Universe deeper and farther than ever before.
Spacecraft service
• In addition to the pure science aspect of the mission, Nasa also wants to upgrade and fix the spacecraft itself, starting with the gyroscopes, which will be upgraded.
• They also are going to install a refurbished fine guidance sensor.
• The batteries are going to be replaced for the first time since Hubble went into space.
• A new outer blanket layer, this time a solid shield, will be put on top of the current blanket.
• Thermal insulation will be replaced on several bays of the telescope.
• A new capture instrument will be installed to recover the Hubble at the end of its life.