Space-based probe passes tests for gravitational wave detection

Gravitational waves — ripples in the fabric of spacetime — can be detected with a space-based observatory, researchers report.

LISA Pathfinder is a European Space Agency satellite, launched on December 3, that has been testing technologies needed to put a gravitational wave detector in space. A space-based detector avoids the rumblings that counterparts on the ground need to deal with, allowing such an observatory to peer much deeper into space. At a June 7 press conference, mission scientists announced that after three months of operation, the orbiting facility has surpassed the precision needed for future missions to detect spacetime disturbances.

That precision equates to measuring changes in the distance between two free-floating cubes, 35 centimeters apart, of roughly a millionth of a millionth of a meter — less than the width of an atomic nucleus. LISA Pathfinder can’t detect gravitational waves; it only shows that a space-based facility can measure such subtle changes. A full-blown gravitational wave detector, planned to launch around 2030, will track the distance between three satellites millions of kilometers apart.