Tuorla Observatory News on 19 April 2005

World's largest space mirror polishing completed

Final polishing of the 3.5 metre mirror for the European Space Agency's Herschel mission has taken place at Tuorla Observatory. The mirror has now been transported back to France by an Airbus Beluga transporter.

The Herschel mirror, shortly before leaving Tuorla Observatory (image by Harry Lehto).

The mirror pioneers the use of silicon carbide (SiC), a novel ceramic material, for use in space. Dr. Tapio Korhonen has developed at the Opteon Labs (sited at Tuorla Observatory) a unique and patented method for polishing SiC, which is a very hard material. Prior to Korhonen's invention, it was very difficult to polish SiC while maintaining the very accurate shapes needed for telescope mirrors.

Tapio Korhonen makes final checks on the 3.5 metre Herschel mirror at Tuorla Observatory (image by Rami Rekola). ESA image of the Herschel satellite by ESA/Medialab.

The mirror will be unique in many ways. When the mission is launched in 2007, it will be the largest ever sent to space. It will be the first SiC mirror used in a telescope, and of course the first to be used in space as well. It will be the first mirror polished to operate at both short radio wavelengths and long infra-red wavelengths. Herschel will be the first entirely European space telescope.

More on the Herschel mission.

  lisää suomeksi.

29/6/2004: The mirror has arrived. The Herschel mirror blank being delivered to Tuorla Observatory's Opteon Lab aboard ESA's Beluga transporter.

Images by Mikko Pasanen

More pictures of the Herschel mirror's trip to Tuorla.

More on the ALADIN mission.

More on the fabrication of the Herschel primary mirror.

This page was last modified by  Rami Rekola  on  31/05/2006 13:54  astroweb@utu.fi