The university’s Institute for Gravitational Research and the Science and Technology Facilities Council’s UK Astronomy Technology Centre (UK ATC) in Edinburgh will develop the optical benches for the European Space Agency’s Laser Interferometer Space Antenna (LISA) mission. These optical benches are at the core of the laser interferometry measurement system, the key technology needed to detect gravitational waves.
The detection of gravitational waves in 2015 marked the start of a new era in astronomy. First predicted by Albert Einstein a century ago, these tiny ripples in the fabric of space-time are generated by cataclysmic events like the merger of black holes or neutron stars and offer an entirely new way to study the universe. The space observatory, planned for launch in the 2030s, will allow scientists to study these mysterious waves, improving our knowledge of the beginning, evolution and structure of the universe.
Chris Lee, Head of Space Science at the UK Space Agency, said: “The University of Glasgow has a worldwide reputation for gravitational waves research, with the pioneering work of Professor Ron Drever in the 1960s leading to the Nobel Prize-winning detection of the waves in 2015. This new funding ensures this legacy continues with the LISA mission, alongside crucial technology innovation from the UK ATC in Edinburgh. Scotland is yet again at the heart of UK space activity.”
Dr Ewan Fitzsimons, who was part of the team at the University of Glasgow which developed the LISA Pathfinder optical bench and is now leading the LISA team at STFC’s UK ATC, said: “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. In addition, the success of the LISA Pathfinder mission, and now the commencement of work on LISA with UK participation has been excellent news. This UK Space Agency investment will ensure that UK scientists are centrally involved in developing and utilising one of the most exciting and significant astronomy projects of the next few decades.”
Dr Harry Ward, who leads the University of Glasgow’s LISA team, said: “The funding announced today sets the Glasgow and UK ATC teams firmly on the road to playing a leading role in a mission that promises to provide dramatically new insights into the nature and evolution of the universe. After working very hard for over 15 years to bring LISA Pathfinder to such a successful conclusion, we are very happy indeed to be so strongly supported to take the crucial next step towards LISA. This commitment from the UK Space Agency will ensure that UK technology will lie at the heart of the most revolutionary astronomy mission of the next 20 years.”
The space observatory will build on the success of the LISA Pathfinder mission, which in 2016 successfully demonstrated the technology needed for LISA. It will also build on work already taking place here on Earth where UK researchers are contributing to the ongoing Laser Interferometer Gravitational Wave Observatory (LIGO) project that made the first detection of gravitational waves in 2015.
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 arises when a gravitational wave passes by. Although the waves are generated by massive, violent events, they are miniscule and the interferometers must measure these tiny squeezes and stretches of the light beams 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 University of Glasgow team designed and built the optical bench for LISA Pathfinder with funding from the UK Space Agency and STFC, supported in the early development phase by STFC’s RAL Space. The LISA Pathfinder mission, which launched in 2015 and ended in 2017, successfully showed that two test masses at the heart of the spacecraft could be put into a state of virtual free fall in space, under the influence of gravity alone and unperturbed by other external forces, with a precision more than five times better than originally required. The Glasgow team will build on this world-leading experience to develop the optical benches for LISA.