Hubble Service Mission 4. The last hurdle.
Sadly, this Service is the last one before Hubble reaches its end-of-life point. Here is a video (shot in a true Hollywood spirit) that describes what will be changed and how long will it last for. Most of the things mentioned in this video had been done yesterday (Fri 15th) by the astronauts, but it is still relevant. Actually, this movie is very professional.