Scientists are one step closer to detecting gravitational waves — ripples in the fabric of spacetime predicted by Albert Einstein in 1915. The LISA Pathfinder, the European spacecraft that houses the technology needed to detect the waves, will launch into space later this year — an event that will give researchers a chance to test the measurement system in space for the first time.

Scientists have been trying to detect gravitational waves, as predicted by Einstein's theory of general relativity, for about 100 years. These waves are produced by large, cataclysmic events in the universe — events like galaxies merging. Confirming that they exist could greatly expand our knowledge of physics by letting scientists "listen" to the universe. But the LISA Pathfinder won't be used to measure gravitational effects just yet. When it launches aboard a Vega rocket, instruments inside the vehicle will be used to measure minute changes in distance between two test masses inside the spacecraft. If the instruments operate as they should, they could end up being used for a gravitational wave detector.

Confirming that they exist could let scientists "listen" to the universe

"The extreme precision of measurements and control required in this domain pose a great technical challenge," César García Marirrodriga, ESA’s project manager, said in a press release. Despite the violent events that trigger them, gravitational waves only cause very small perturbations in the fabric of spacetime. That's why the instruments' precision is so important.

After its ascent on a Vega rocket, the LISA Pathfinder will enter orbit around the Earth. Eight weeks later, the spacecraft will begin a six-month technology demonstration. If everything goes according to plan, and the technologies work, the ESA will use them in a second mission, named L3, to look for gravitational waves. Right now, L3 has a tentative launch date of 2034.