World's largest space mirror polishing completed
Final polishing has taken place at Tuorla Observatory of the
3.5 metre mirror for the European Space Agency's Herschel
mission. 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
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
1.7.2004. The mirror has arrived. The Herschel mirror blank being delivered
to Tuorla Observatory's Opteon Lab aboard ESA's Beluga transporter.
Images courtesy 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
Updated 19th April 2005