Launched in December 2015, LISA Pathfinder travelled to its operational orbit, 1.5 million km from earth towards the Sun, where it started its scientific mission on 1 March. <br /> <br />At the core of the spacecraft, two identical gold-platinum cubes, are being held in the most precise free-fall ever produced in space. <br /> <br />Placing the test masses in a motion subject only to gravity is the challenging condition needed to build and operate a future space mission to observe gravitational waves. Predicted by Albert Einstein a century ago, gravitational waves are fluctuations in the fabric of space-time, which were recently detected directly for the first time by the Laser Interferometer Gravitational-Wave Observatory. <br /> <br />Over the first two months of scientific operations, the LISA Pathfinder team has performed a number of experiments on the test masses to prove the feasibility of gravitational wave observation from space. <br /> <br />These results are explained in this video with interviews of Paul McNamara, LISA Pathfinder Project scientist, ESA and two LISA Pathfinder Principal investigators : Rita DOLES, University of Trento and Martin Hewitson, University of Hannover.