The Laser Interferometer Space Antenna (LISA) is a Space mission led by ESA now entering its phase A. LISA will be the first observatory in space to explore the Gravitational Universe. It will gather revolutionary information about the dark universe. The new LISA mission envisaged as a joint ESA-NASA mission to observe astrophysical and cosmological sources of low frequency gravitational waves. The primary objective of the LISA mission is to detect and observe gravitational waves emitted from massive black holes and galactic binaries in the low-frequency band which ranges from 0:1mHz up to 1Hz with a goal of extending the measurements down to 30mHz.