Euclid Mission: investigating the depths of the universe...
The European Space Agency recently unveiled the first color images of the Universe captured by the Euclid mission, launched on July 1, 2023, from the Cap Canaveral base. The space telescope, with the ambition to unravel the secrets of the Universe, carries several key instruments designed by Safran.
1.20 m: that's the diameter of the Euclid space telescope, half the size of the Hubble telescope, which was instrumental in fundamental discoveries about the Universe. Euclid's mission is to precisely map the Cosmos during its six years in space. It will observe billions of galaxies, some located up to 10 billion light-years away. Objectives: decrypting dark matter, whose existence has yet to be demonstrated, and unraveling the mystery of dark energy, which would explain the rate of expansion of the Universe.
"Participating in Euclid is a great source of pride for the Safran Reosc teams, where our unique expertise in creating large, high-performance space mirrors serves a major mission for understanding the Universe, studying its expansion over the last ten billion years."
Mirror, mirror on the Wall...
The telescope carries three mirrors made of silicon carbide (SiC): a primary (M1) and two secondaries (M2 and M3). Executed by Safran Electronics & Defense, through its company Safran Reosc, the meticulous polishing of the primary mirror, crucial for image quality, was done robotically, with ion milling finishing, limiting surface defects to less than 10 nanometers. This is one of the largest space mirrors in SiC made with such optical performance!
Special silver-protected space-qualified treatment has also been applied to the three mirrors M1, M2, and M3. This protective coating has already been used by Safran Electronics & Defense for treating mirrors in several scientific space missions and Earth observation (James Webb Space Telescope, Gaia, Pleiades Neo).
Safran Electronics & Defense has developed three key mechanisms for the Euclid space telescope. Firstly, the orientation mechanism of the RSU (Readout Shutter Unit) shutter, a shutter placed upstream of the focal plane, automatically closes after each shot to block stray light. This mechanism opens and closes in about 10 seconds during Euclid's six years of operation in space.
Safran Electronics & Defense has also delivered cryomotors enabling the rotation of the filter wheels of the NISP instrument (Near IR Spectrometer Photometer - a wide-field spectrometer operating in the near-infrared). It allows space observation in photometry or spectrometry, both modes being essential for measuring the shape and age of galaxies. The cryomotors facilitate the transition from one mode to another.
Finally, Safran Electronics & Defense also plays a role in the communication aspect of the Euclid satellite with Earth: in addition to the usual Cortex modems found on the ground in various European Space Agency stations, Safran also enables the pointing of the satellite's communication antennas towards Earth through the three motors of the Antenna Deployment & Pointing Mechanism (APDM).
Unveiling the secrets of the Universe: Euclid takes its first steps
The space telescope revealed its first images of the Universe on November 7, 2023, several months ahead of the scheduled timeline. Scientists, as well as the general public, eagerly await Euclid's future discoveries.
What is Dark Matter?
Dark matter, a captivating mystery, remains invisible to light and other forms of radiation. It constitutes about 85% of the total matter in the Universe. Its existence is inferred through the gravitational effects it exerts on galaxies, galaxy clusters, and the Universe as a whole.
Indications of the presence of dark matter date back to the early 20th century, and so far, its composition remains enigmatic. Understanding its nature and potential distribution could revolutionize our perception of the Universe and lead to new theoretical advancements.