Euclid, a planned mission to investigate the profound cosmic mysteries of dark matter and dark energy, has passed its preliminary design review. This clears the way for construction to begin. Euclid is a European Space Agency mission with important contributions from NASA, including infrared detectors for one instrument and science and data analysis.

Euclid is designed to give us important new insights into the "dark side" of the universe - namely dark matter and dark energy, both thought to be key components of our cosmos.

"We are excited for the opportunity to contribute the critical detector component for Euclid's near-infrared instrument and look forward to working closely with ESA on this important mission," said Ulf Israelsson, the NASA Euclid project manager at NASA's Jet Propulsion Laboratory in Pasadena, California.

"This is really a big step for the mission," said Giuseppe Racca, ESA's Euclid project manager. "All the elements have been put together and evaluated. We now know that the mission is feasible and we can do the science."

Observations made over recent decades reveal that the normal matter - what you find in everyday objects and in our own bodies - is actually only a fraction of the total matter in the universe. The rest is dark matter, an invisible substance whose existence can be inferred through its gravitational pull.

Dark energy is even more mysterious than dark matter. It is thought to explain why space is not only expanding, but stretching apart at ever-increasing speeds.

By mapping the shapes, positions and movements of two billion galaxies across more than a third of the sky, Euclid will provide astronomers with an unprecedented wealth of data to infer the presence of dark matter and dark energy indirectly. The unrivaled accuracy of the mission's measurements will bring astronomers closer to solving the mystery of these baffling entities.

First proposed to ESA in 2007, Euclid was selected as the second medium-class mission in the Cosmic Vision program in October 2011. Italy's Thales Alenia Space was chosen as the prime contractor in 2013.

Since then, the mission's design has been studied and refined. This process has involved a wide range of detailed technical designs, in addition to building and testing key components.

The outcome of Euclid's recent review was positive, opening the door for the industrial contractors and external instrument teams building the spacecraft and payload. Airbus Defence and Space in France will deliver the complete payload module incorporating a 3.9-foot-diameter (1.2-meter) telescope feeding the two science instruments being developed by the Euclid Consortium.

"This is a major milestone for us. Everyone is now ready to start cutting metal," said Rene Laureijs, ESA's Euclid project scientist.