The proof of gravitational waves predicted by Einstein is regarded as one of the greatest milestones in the history of physics. In 2017, the first measurement within the LIGO & VIRGO project was awarded the Nobel Prize in Physics.
In order to measure even more sensitively and, above all, with less interference, scientists of the European Space Agency (ESA) are working on the space-based measurement of gravitational waves as part of the LISA (Laser Interferometer Space Antenna) mission. While the measurements in the LIGO project are earth-based, LISA uses satellites to take measurements from space for the first time. This offers the advantage of detecting even lower frequency ranges of gravitational waves and eliminating disturbing influences on the earth.
Astronomers tested the LISA mission as early as 2016 using the predecessor project LISA Pathfinder. As part of LISA Pathfinder, scientists sent a test satellite into space with a smaller replica of the future measurement and control systems. The mission was successful - testing all key techniques of the LISA mission in space under the existing conditions was possible.