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Space mission for gravitational waves gets green light

The European Space Agency (ESA) has approved the proposal for gravitational wave detector LISA. The launch for the space detector is planned in 2034. ‘A dream that comes true,’ says astronomer Elena Maria Rossi.

Measuring long waves

The Laser Interferometer Space Antenna (LISA) will be able to do detect gravitational waves in space. Astronomers measure these waves also from Earth. This happened for the first time with interferometers of the LIGO Virgo Collaboration on 14 September 2015. The thereby measured gravitational waves had a short wave length. LISA aims at waves with a much longer wave length. It will measures these waves in space with an installation of three satellites.

Dream from the seventies

‘This project started as a dream a long time ago, and remained a dream for a very long time,’ says Rossi of Leiden Observatory. ‘The idea started at the end of the seventies, so it is really fantastic that it finally has been approved.’ Rossi is one of the forerunners of this project. She wrote the ESA proposal together with a core team consisting of international scientists and institutes. Dutch contributors are Gijs Nelemans of Radboud University and the research institutes SRON, Nikhef, TNO and the joint educational institute NOVA.

White dwarfs and black holes

‘My group has a lot of knowledge in the field of supermassive black holes and double white dwarfs,’ Rossi explains the contribution of her Leiden Observatory group to the project. ‘LISA is the only gravitational wave experiment that will allow us to study our own Galaxy mainly through observations of white dwarf binaries. For this proposal, we have made predictions on how many of these important systems LISA will observe. In addition, we looked at which fraction we can observe in visible light with another ESA mission with a strong Dutch and Leiden contribution: Gaia. LISA and Gaia in synergy can bring us closer to the understanding of our host Galaxy.'

Dutch instruments

The Dutch expertise institute SRON informed ESA by means of a letter of endorsement in March, on behalf of the Dutch institutes,  that they are willing to contribute to the development of the space installation. SRON and Nikhef are working jointly one a phase meter, which is able to detect minimal distance changes between the satellites in the installation in space. TNO earlier developed precision optomechanical parts, essential for aiming the laser between the satellites.