The European Space Agency has approved the so-called adoption of the Laser Interferometer Space Antenna (LISA) mission with a budget of €1.75 billion. A mission adoption is an important milestone in the development of space projects, where the European Space Agency takes a project from the assessment phase to the actual implementation of concepts and technologies. The three satellites of the LISA mission, a unique scientific project aimed at detecting and studying gravitational waves from space, are scheduled to be launched in 2035 on an Ariane 6 rocket.
The satellites will form an equilateral triangle in space. They will send a laser beam between themselves over a distance of 2.5 million kilometres and measure the laser beam phases. These will change as the gravitational wave passes through space, making it possible to detect signals from, for example, the collision of supermassive black holes in galaxies billions of light years away.
"We are very pleased that the Czech Republic has become increasingly involved in gravitational wave research in recent years. The involvement in a cutting-edge space project is very important for us and the fact that we have been entrusted with the production of a key component for the LISA probes indicates high quality of Czech science," says Michael Prouza, Director of the Institute of Physics of the Czech Academy of Sciences.
The mechanism for correcting the laser beam polarization when switching between primary and redundant lasers is being developed by a consortium of four institutes of the Academy of Sciences. The photo shows a working prototype Photo: Jan Ebr
"In particular, scientists will observe the gravitational waves originating from supermassive black hole mergers at the centres of colliding galaxies, which will allow them to better understand the growth of these giant black holes at the centres of galaxies, including our own Milky Way. Gravitational waves carry information about the distance of the objects that send them out, so the LISA mission will allow researchers to measure changes in the expansion of the Universe on a type of scale different from that used by ground-based observatories. In fact, gravitational wave observatories located in space will make it possible to observe more massive systems at lower frequencies than ground-based ones," adds Jiří Svoboda from the Astronomical Institute of the Czech Academy of Sciences, who together with Michael Prouza is the investigator of the Czech project in ESA's PRODEX programme, which ensures the involvement of Czech scientists.
A total of 12 lasers will be installed on the three probes of the LISA mission, 4 per probe, as well as a backup unit for each of them in case the main laser fails. In case the mission operators need to switch to the backup laser, the Fibre Switching Unit (FSU) will rotate the laser polarization by 90 degrees to match the polarization of the main laser. And it is this mechanism for correcting the laser beams polarizations that is being developed by a consortium of four institutes of the Academy of Sciences – the Astronomical Institute, the Institute of Physics, the Institute of Atmospheric Physics and the Institute of Thermomechanics. The researchers have already succeeded in creating a working prototype and fitting a sliding piezoelectric actuator and position encoder into the very small volume allowed.
The project to develop the so-called Fibre Switch Unit Actuators, critical mechanisms for the optical benches on the LISA mission spacecrafts, that will be used while switching between two laser beam sources, was also supported in the past by the Ministry of Education, Youth and Sports, as well as the Ministry of Transport.