SCHOTT assists the European Extremely Large Telescope (ELT) to provide the 500th sub-mirror for the M1 primary mirror

• SCHOTT actively participated in the European Southern Observatory's Extremely Large Telescope project in Chile and successfully produced the 500th sub-mirror for its M1 primary mirror.

• SCHOTT mass-produces ZERO® glass-ceramic mirror substrates to meet the highest surface quality requirements of the European Southern Observatory.

• Specialty glass maker SCHOTT is producing 949 hexagonal sub-mirrors (to be spliced into the M1 large primary mirror) for the world's largest optical telescope, which is expected to be operational by the end of 2027.

SCHOTT has successfully produced the 500th mirror blank for the European Southern Observatory's Extremely Large Telescope (ELT) M1 primary mirror. It is reported that the telescope is expected to be put into use in 2027, when it will also become the world's largest "eye in the sky". The 39-meter-diameter primary mirror is made up of 798 hexagonal sub-mirrors made of SCHOTT Zero® glass-ceramic, in addition to 133 spare sub-mirrors and 18 prototype sub-mirrors from SCHOTT. With a coefficient of thermal expansion close to zero, Zero Degree ® has become the industry-recognized gold standard of choice for mirror substrates for tiled telescopes and is used in a wide variety of high-tech and industrial applications.

As the supplier of the main mirror M1 sub-mirror of the European Southern Observatory's Extremely Large Telescope, the multinational high-tech group SCHOTT has successfully produced its 500th ZERO® mirror blank. The Extremely Large Telescope (ELT), currently under construction on the Cerro Armazones in Chile's Atacama Desert, will become the world's largest optical telescope, with a primary mirror with a diameter of 39 meters and is expected to be commissioned in 2027 use.

In 2017, SCHOTT signed a contract with the European Southern Observatory (ESO) to supply 949 ZERO® blanks (including 798 sub-blanks, 133 spare sub-mirrors and 18 mirror blanks) for the M1 primary mirror of the Extremely Large Telescope (ELT). Prototype mirrors) and deliver the first prototype mirrors in 2019. In 2020, SCHOTT will start mass production of mirror blanks for the Very Large Telescope at its headquarters in Mainz, Germany, with the last batch to be produced in early 2024. In addition to the primary mirror blanks, ZERO® will be used for the Very Large Telescope's convex secondary mirror M2 (4.2 m), concave triple mirror M3 (3.8 m) and adaptive optics mirror M4 (2.4 m). After production is complete, SCHOTT transports the mirror blanks to SAFRAN Reosc in France for polishing. Celebrating this production milestone, Thomas Werner, Project Leader for SCHOTT's Extremely Large Telescope, said: "We are delighted that SCHOTT can provide important support for the European Southern Observatory's Extremely Large Telescope project and contribute to shaping the future of astronomy. pride!".

Zero Degrees®: Specialty Materials for Superior Performance

ZERO® glass-ceramics are renowned for their high thermal and mechanical stability in astronomical and industrial applications. ZERO® was developed by SCHOTT in 1968 in cooperation with the Max Plank Institute for Astronomy in Germany and plays a key role in many high-tech applications requiring extreme precision, such as navigation systems and Lithographic apparatus for integrated circuit fabrication. In addition to its near-zero thermal expansion rate and excellent uniformity, its mechanical and chemical properties make it robust in extreme conditions on Earth or in space. In the production of the mirror blanks for the Very Large Telescope in cooperation with the European Southern Observatory, SCHOTT drew on its long experience in the mass production of glass-ceramics for industrial applications. SCHOTT has also supported the European Southern Observatory on other projects, such as the supply of the 8.2-meter ZERO® primary mirror for the production of four element mirrors for the Very Large Telescope (VLT).