Free Astronomy Magazine January-February 2016

32 ASTRONAUTICS space. The task of LISA Pathfinder is pre- cisely to show that it can be done and that consequently researchers can start putting the project in the pipeline on a larger scale, that is to say the real LISA, the one truly ca- pable of recording gravitational waves. It should be noted that when the laser sys- tem signals a displacement, even infinites- imal, of the cubes, the probe laboratory housing them compensates in turn this dis- placement by moving itself, through a mi- cro-propulsors system developed by NASA called Disturbance Reduction System. It is capable of generating pulses so small and precise that it can move the whole struc- ture by a few nanometers with respect to the cubes that it houses (which will con- tinue to float freely). The nominal duration of the mission is 6 months (with possible extension to 1 year). During the first 3 months the LISA Technol- ogy Package will be tested, while in the fol- lowing 2 it will be turn of the Disturbance Reduction System, and only in last month both systems will work together. With this mission, the final confirmation of the exis- tence of gravitational waves is getting clos- er, but it still remains a long-term goal. n T his image, tak- en from a nu- merical simulation, depicts the struc- ture of gravitation- al waves that are generated when two supermas- sive black holes merge. These events represent the most power- ful sources of grav- itational waves. [NASA/C. Henze]