Hubble and Kepler telescopes, illustration. The Hubble Telescope was launched in 1990 into low Earth orbit by Space Shuttle Mission STS-31 Discovery. It had to be repaired and serviced in five Space Shuttle missions until 2009. It is 13.2 meters long with a diameter of 4.2 meters. The weight was 11.1 tonnes. The Kepler Telescope was launched on March 7th, 2009 to survey a portion of the Milky Way to discover Earth-size exoplanets in or near habitable zones. It's size is 4.7 m long and weights 478 kg. Kepler observed 530 506 stars and detected 2 662 planets.