The European Space Agency is postponing the launch of probe that will test technology for a future mission to measure gravitational waves.
The agency said Tuesday that a technical problem has been discovered in the Vega rocket that was due to lift the probe into orbit Wednesday. Engineers are working on fixing the problem and the launch from French Guiana may take place Thursday.
Scientists hope the $450-million LISA Pathfinder mission will demonstrate it's possible to shield objects from external influences well enough to detect the minute effects of gravitational waves.
If it succeeds, the agency plans to launch a follow-up mission in 2034 that could measure ripples in space-time caused by black holes and other massive objects lurking unseen in dark corners of the galaxy.