„Space, the final frontier.“ Thus begins every episode of the cult series cult series Star Trek. But it is not just the fans of Captain Kirk, Mr. Spock und co. that are fascinated with outer space: nearly 1.3 million people follow the astronaut geophysicist Alexander Gerst on Twitter, for example. Since the beginning of humanity, we have been trying to read the stars, to explore the limitless expanses of space and to comprehend it scientifically. But highly-developed space telescopes are needed to observe the stars. Such telescopes can be found on board the Gaia space probe of the European Space Agency (ESA), for instance – with a special coating made of silicon carbide (SiC) from Schunk Carbon Technology.
Schunk is a regular participant in international space projects. But the collaboration with the ESA on the Gaia space probe is certainly a special highlight. The probe is carrying out a high-precision, three-dimensional survey of the entire sky. In addition to the exact position of the stars of our galaxy, their movements are also being tracked, which in turn makes it possible to determine other data, such as light output, temperature and much more. Gaia originally received its name from the acronym for Global Astrometric Interferometer for Astrophysics. However, in Greek mythology, Mother Earth is also named Gaia. The telescope being used on Gaia is providing the most accurate map of the Milky Way to date, offering highly precise measurements of some 1.7 billion stars as well as details which have hitherto not been visible.
Precision, know-how and experience for Gaia
Schunk Carbon Technology has longstanding experience in the coating of space telescopes and their mirrors. These are used in both national and international projects. Currently, some 10 to 15 of these are coated by Schunk per year. Gaia alone has a total of 10 mirrors, which combine and relay the light from the two telescopes. They are made of sintered silicon carbide. But when cut this material does not produce a smooth, non-porous surface. That’s why Schunk coats the material with an additional layer of silicon carbide. This makes the surface highly reflective, absolutely airtight and particularly resistant as silicon carbide is almost as hard as diamond.
A milestone in space exploration
Schunk Carbon Technology is well-experienced in the use of silicon carbide. The material possesses good mechanical properties and a low density, which make it especially suitable for weight-sensitive applications. Some space telescopes not only have silicon-carbide coated mirrors but also frames and mountings made of the same material. This allows the construction of very large albeit lightweight telescopes which are able to withstand the large temperature fluctuations they are subjected to in outer space. The manufacturing technique used by Schunk produces an absolutely airtight and non-porous coating made of silicon carbide, the quality of which is unique in the industry. Moreover, Schunk is currently the only supplier that is able to coat the particularly large parts that are commonly used in space projects.
Gaia transmits its data to Earth 11 hours a day. Astronomers claim they are receiving the best photographs they have ever received of Milky Way and that the data they receive is redefining the foundations of their research, and the telescope mirrors coated by Schunk’s silicon carbide are making a significant contribution.