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.
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 |