UK scientists to build the instruments that will explain the Universe

The team will work on the world’s first ever Gravitational Wave Space Observatory thanks to an initial £1.7m of funding from the UK Space Agency.

Glasgow University’s Institute for Gravitational Research and STFC’s UK Astronomy Technology Centre (UK ATC) in Edinburgh will develop the optical benches for the European Space Agency’s LISA mission (Laser Interferometer Space Antenna). These optical benches are at the core of the laser interferometry measurement system and are essential for detecting gravitational waves.

Scheduled to launch in the 2030s, LISA is expected to build on the success of the LISA Pathfinder mission, which in 2016 successfully demonstrated the technology needed for LISA.

First predicted by Albert Einstein, gravitational waves are tiny ripples in the fabric of space-time generated by cataclysmic events like the merger of black holes. The detection of gravitational waves by the ongoing LIGO project in 2015 marked a new era in astronomy that offers an entirely new way to study the Universe.

“It’s a very interesting time right now – the amazing science that LIGO has enabled is showing us the potential of gravitational wave astronomy to revolutionise our understanding of the Universe,” said Dr Ewan Fitzsimons, who was part of the team at Glasgow University which developed the LISA Pathfinder optical bench and is now leading the LISA team at STFC’s UK ATC. “In addition, the success of the LISA Pathfinder mission, and now the commencement of work on LISA with UK participation, has been excellent news.”

Gravitational waves can be studied from space, away from ground-based ‘noise’ and measured over vast distances. LISA will be able to observe new sources invisible to the ground-based gravitational wave observatories like LIGO. The LISA mission will study these gravitational waves using three spacecraft flying in a triangular configuration, separated from each other by a distance of 2.5 million km. At the heart of each spacecraft will be an interferometer.

These interferometers fire laser beams between each satellite, using them to measure tiny fluctuations in the distance between the spacecraft, which arise when a gravitational wave passes by. Although the waves are generated by massive, violent events, they are minuscule and the interferometers must measure these fluctuations to a few trillionths of a metre.

To support this, the optical components of the interferometer must be arranged on an innovative optical bench that is thermally and mechanically isolated from any other effects apart from gravitational waves.

The team at Glasgow University designed and built the optical bench for LISA Pathfinder with funding from the UK Space Agency and STFC. LISA Pathfinder used one optical bench, which the Glasgow team built by hand, while LISA will require up to 12 benches. STFC’s UK Astronomy Technology Centre will partner with Glasgow University to develop the technology and lead the overall design and build of the LISA optical benches.

The first optical bench is due to be delivered to ESA around 2030.