The European spacecraft designed to make gravitational wave detection possible from space will begin taking science data on Tuesday. Lisa Pathfinder was launched on 3 December and arrived in its operational orbit, some 1.5m km from Earth, closer to the Sun, on 22 January. Since then, operators have been testing that everything is functioning correctly.
At the heart of the mission are two separate 46mm gold-platinum cubes. These were clamped in position for launch but are now floating freely inside cavities in the spacecraft. Equipment will monitor their movement. If they move in perfect synchrony then the mission will be deemed a success because it proves that the two masses have been successfully isolated from all forces except gravity.
This would mean that a scaled-up version could detect gravitational waves. Gravitational waves are minuscule ripples in the spacetime continuum. Typically less than a thousandth the width of an atomic nucleus, they can be caused by collisions between massive stellar objects such as black holes, or the explosion of stars.
The first detection of gravitational waves was announced on 11 February from the Earth-based observatory Ligo. It caught a pair of large black holes colliding 1.3bn light years away. In space, lower frequencies of gravitational waves could be detected, allowing astronomers to watch the birth of galaxies more than 10bn light years away.
Lisa Pathfinder is now poised to test the technology to allow this to happen.
