A groundbreaking technology demonstration by the LISA Pathfinder spacecraft could pave the way for detecting mergers of supermassive black holes using space-based observatories.

The European Space Agency spacecraft LISA Pathfinder consists of two 4.6-centimeter gold-platinum cubes sitting 1.5 million kilometers from Earth in an area so calm, it can “listen” for gravitational waves, according to a NASA/Goddard Space Flight Center statement.

Gravitational waves exploded onto the national consciousness a few months ago when it was reported that scientists had detected them for the first time, confirmed Albert Einstein’s predictions as part of his general theory of relativity. Its a discovery that could help us better understand that most dramatic incidents in the universe, including exploding suns, neutron stars, and supermassive black holes smashing into each other.

The waves are incredibly hard to document because they produce tiny ripples in the fabric of spacetime. LISA Pathfinder was launched in December 2015 to help scientists better perform measurements via the “Laser INterferometer Space Antenna” (LISA). LISA would be able to seek out gravitational waves from black hole merges across the universe.

“LISA Pathfinder was always intended as a stepping stone to the level of performance needed for a full-scale gravitational wave observatory, but these results tell us we’ve nearly made the full jump. A full-scale observatory with LISA Pathfinder’s performance would achieve essentially all of the ultimate science goals,” said Ira Thorpe, a team member at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “That’s amazing in itself, and data from this mission will help us build on an already impressive foundation.”