Fleet of spacecraft to detect gravitational waves

The green light has been given for the construction of three LISA (Laser Interferometer Space Antenna) spacecraft, whose pioneering mission will be to detect and study gravitational waves from space.

The European Space Agency’s (ESA) Science Program Committee approved the construction of the spacecraft and their scientific instruments. The project has already been sufficiently developed and it has been established that it is already technologically feasible in practice.

These works will begin in January 2025, when a European company will be selected as the general contractor. Member countries’ space agencies also collaborate with ESA, as well as NASA (the US space agency) and an international consortium of scientists.

The LISA fleet will consist of three identical spacecraft flying in formation. They will orbit the Sun, following the Earth, forming an equilateral triangle in space. Each side of the triangle will be 2.5 million kilometers long (more than six times the distance between Earth and the Moon), and over this distance the spacecraft will exchange laser beams.

The three spacecraft are scheduled to launch in 2035 using an Ariane 6 rocket.

The illustration shows two black holes merging and creating ripples in the fabric of space-time. You can see several galaxies in the background. In the foreground, bright red lines outline the shape of a triangle that represents the position of the three LISA spacecraft and the laser beams that will pass between them. (Image: ESA CC BY-SA 3.0 MPO)

Just over a century ago, Einstein made the revolutionary prediction that when massive objects accelerate, they shake the fabric of space-time, creating tiny ripples or wrinkles known as gravitational waves. Thanks to modern technological advances over the past few years, we have been able to detect these elusive signals. So far they have been captured from special objects on the surface of the Earth. With LISA, a new and exciting step is taken in which gravitational waves will be detected that would be impossible to detect from the surface of the Earth.

Using laser beams projected over distances of several kilometers, ground-based instruments can detect gravitational waves from events involving star-sized objects, such as supernova explosions or mergers of super-dense stars and stellar-mass black holes. Thanks to the enormous distance that laser signals travel at LISA and the excellent stability of its instruments, it will be possible to detect gravitational waves at frequencies lower than those that can be detected from Earth, allowing the discovery of events on a different scale since the last century. before the beginning of time, according to the scientific team’s Nora Lutzgendorf.

LISA will detect ripples in spacetime throughout the universe caused by the collisions of huge black holes at the centers of galaxies. This will allow scientists to trace the mysterious origins of these monstrous objects, billions of times more massive than stellar-mass black holes, track how they grow, and figure out the role they play in the evolution of galaxies.

The mission is designed to capture the gravitational “buzz” of the early moments of our Universe and reveal new data about the first seconds after the Big Bang, the colossal “bang” that gave birth to the Universe. Additionally, because gravitational waves carry information about the distance to the objects that emit them, LISA will help researchers measure changes in the expansion of the Universe using a different type of measuring stick than methods used on other space missions, thereby confirming their results. or suggesting alternatives if there are discrepancies. (Fountain: NCYT by Amazings)