ESA’s Euclid spacecraft lifted off on a SpaceX Falcon 9 rocket from Cape Canaveral Space Force Station in Florida, USA, at 17:12 CEST on 1 July 2023. The successful launch marks the beginning of an ambitious mission to uncover the nature of two mysterious components of our Universe: dark matter and dark energy, and to help us answer the fundamental question: what is the Universe made of?

Following launch and separation from the rocket, ESA’s European Space Operations Centre (ESOC) in Darmstadt, Germany, confirmed the acquisition of signal from Euclid via the New Norcia ground station in Australia at 17:57 CEST.

“The successful launch of Euclid marks the beginning of a new scientific endeavor to help us answer one of the most compelling questions of modern science,” says ESA Director General Josef Aschbacher. “Euclid has been made possible by ESA’s leadership, the effort and expertise of hundreds of European industrial and scientific institutions, and through collaboration with international partners. The quest to answer fundamental questions about our cosmos is what makes us human. And, often, it is what drives the progress of science and the development of powerful, far-reaching, new technologies. ESA is committed to expanding Europe’s ambitions and successes in space for future generations.”

“The Euclid mission is the result of the passion and expertise of those who contributed to designing and building this sophisticated space telescope, the competence of our flight operations team, and the inquiring spirit of the science community,” says Giuseppe Racca, ESA’s Euclid Project Manager. “There have been many challenges during the project, but we have worked hard and now we have successfully reached this launch milestone together with our partners in the Euclid Consortium and NASA.”

The Euclid Consortium contributed two highly advanced scientific instruments – the visible-wavelength camera (VIS) and the Near-Infrared Spectrometer and Photometer (NISP). NASA provided the detectors for NISP.

Exploring the Dark Universe

Euclid will observe billions of galaxies out to 10 billion light-years to create the largest, most accurate 3D map of the Universe, with the third dimension representing time itself. This detailed chart of the shape, position, and movement of galaxies will reveal how matter is distributed across immense distances and how the expansion of the Universe has evolved over cosmic history, enabling astronomers to infer the properties of dark energy and dark matter. This will help theorists to improve our understanding of the role of gravity and pin down the nature of these enigmatic entities.

“Today we celebrate the successful launch of a ground-breaking mission that places Europe at the forefront of cosmological studies,” says Carole Mundell, ESA’s Director of Science. “If we want to understand the Universe we live in, we need to uncover the nature of dark matter and dark energy and understand the role they played in shaping our cosmos. To address these fundamental questions, Euclid will deliver the most detailed map of the extra-galactic sky. This inestimable wealth of data will also enable the scientific community to investigate many other aspects of astronomy, for many years to come.”

To achieve its ambitious scientific goal, Euclid is equipped with a 1.2 m reflecting telescope that feeds the two innovative scientific instruments: VIS, which takes very sharp images of galaxies over a large fraction of the sky, and NISP, which can analyze galaxies’ infrared light by wavelength to accurately establish their distance.

The spacecraft and communications will be controlled by ESOC. To cope with the vast amounts of data Euclid will acquire, ESA’s Estrack network of deep space antennas has been upgraded. These data will be analyzed by the Euclid Consortium – a group of more than 2000 scientists from more than 300 institutes across Europe, the US, Canada, and Japan.

As the mission progresses, Euclid’s treasure trove of data will be released with a yearly cadence and will be accessible to the global scientific community via the Science Archive hosted at ESA’s European Space Astronomy Centre in Spain.

“This is a great moment for science, one that we have long been looking forward to the launch of Euclid, on a mission to decipher the puzzle of dark matter and dark energy,” says René Laureijs, ESA’s Euclid Project Scientist. “The big mystery of the fundamental constituents of the Universe is staring us in the face, offering a formidable challenge. Thanks to its advanced telescope and powerful scientific instrumentation, Euclid is poised to help us unravel this mystery.”

Journey to Lagrange Point 2

In the next four weeks, Euclid will travel towards Sun-Earth Lagrange point 2, an equilibrium point of the Sun-Earth system located 1.5 million km from Earth (about four times the Earth-Moon distance) in the direction opposite from the Sun. There, Euclid will be maneuvered into orbit around this point and mission controllers will start the activities to verify all the functions of the spacecraft, check out the telescope and finally turn on the scientific instruments.

Scientists and engineers will then be engaged in an intense two-month phase of testing and calibrating Euclid’s scientific instruments and preparing for routine observations. Over six years Euclid will survey one-third of the sky with unprecedented accuracy and sensitivity.

Click here to learn about Euclid's mission to explore the evolution of the dark universe.