The LISA Pathfinder spacecraft is due to set off in autumn 2015 in a bid to prove that it is possible to observe gravitational waves in space. This is the latest step in an incredible journey to spot these ripples in spacetime that were first predicted by Albert Einstein 100 years ago.
If we can manage to capture these waves, then we should be able to observe some of the most violent events in the cosmos, such as black holes colliding and galaxies merging. For the moment, however, we're still searching.