The European Space Agency’s Laser Interferometer Antenna (LISA) is on its way to becoming the first space-based observatory specifically designed to study gravitational waves, after European space technology group OHB System AG signed its recent contract to begin construction on the project.
The mission will involve three separate spacecraft as it seeks to detect the spacetime ripples generated by the collision of supermassive black holes and other powerful events. OHB System AG and ESA signed the contract at France’s International Paris Airshow, held June 16-22, 2025.
Heading into Production
“We are immensely proud that ESA and the scientific community entrust us to implement this groundbreaking science mission. Together with our partners we stand ready to bring LISA to life – pioneering our ability to ‘surf gravitational waves’ and enabling us to see our Universe in a new way,’ said Chiara Pedersoli, CEO of OHB System AG.
Since entering the space sector in Germany during the 1980s, OHB System AG has been involved in major programs such as the International Space Station and the upcoming Lunar Gateway, part of NASA’s Artemis program.
“I’m delighted to celebrate the contract signing today with our partners at OHB who will lead on the implementation of this truly ambitious endeavour,” said Professor Carole Mundell, ESA’s Director of Science. “LISA represents many years of pioneering technology developments, hope and belief of our scientific community, and steadfast support from our ESA member states.”
Detecting Gravitational Waves
By operating in space rather than from the ground, LISA will be able to capture low-frequency gravitational waves that are inaccessible to Earth-based detectors. These low-frequency waves are expected to provide evidence of large-scale events that reach back to the earliest moments of the universe.
“As the first space mission designed to capture gravitational waves, LISA will open a brand-new window on the dark Universe and test the known laws of physics to their extreme,” Mundell said. “When it is flying, LISA will also represent the triumph of precision engineering and international cooperation on a new scale, and place Europe at the forefront of space technology and fundamental science.”
Scientists expect LISA to deliver new data on some of the most fundamental cosmic questions, including the nature of gravity, the rate of universal expansion, and the activity of supermassive black holes. On a more localized scale, it will also advance research into stellar-origin black holes and the formation and evolution of compact binary star systems within the Milky Way.
The Triangle Mission
The mission is currently scheduled to launch in 2035 aboard an Ariane 6 rocket, developed by ArianeGroup for ESA. A new addition to Europe’s launch capabilities, the Ariane 6 successfully delivered its first commercial payload on March 6 of this year.
LISA will fly in a triangular formation, consisting of three spacecraft that follow Earth’s orbit around the Sun. Each will remain separated by 2.5 million kilometers, forming an equilateral triangle that trails the planet. The spacecraft will exchange laser beams to measure gravitational waves—over distances more than six times the span between Earth and the Moon. This kind of triangular configuration has never before been attempted in spaceflight.
Each spacecraft will carry two test masses—small cubes made from a gold-platinum alloy—suspended inside free-floating housings. Using laser interferometry, LISA will track minuscule changes in the distances between the cubes. This will allow it to detect gravitational waves by measuring variations as small as a billionth of a millimeter over millions of kilometers. The system will be sensitive enough to register distance shifts comparable in size to a single helium atom.
Ryan Whalen covers science and technology for The Debrief. He holds an MA in History and a Master of Library and Information Science with a certificate in Data Science. He can be contacted at ryan@thedebrief.org, and follow him on Twitter @mdntwvlf.