Herschel Telescope Flight Model at ESTEC
1 February 2008The Herschel telescope's primary mirror is the largest mirror ever built for space. It is made out of 12 silicon carbide (SiC) petals brazed together and coated with a thin aluminium reflective layer. The SiC provides a rigid but lightweight structure with the telescope mass totalling at about 320 kg.
In the morning on Friday 18 January, the flight model of the 3.5-metre diameter telescope arrived at ESTEC in Noordwijk on its transporter truck. Upon arrival the outside of the telescope container was first cleaned before the transport was turned to cleanroom loading bay-airlock #3 for unloading of the container holding the large telescope.
On 24 January, the unpacking of the telescope was performed in the cleanroom, starting with the lifting of the transport container cover. The images below show the telescope – still with a white protective cover – being hoisted from its transport stand onto its ground handling system.
Tuesday, 29 January, the telescope was successfully cleaned after removal of its protective white cover, with ETS and ISS cleaning services providing material support.
Next, the detailed inspection of the telescope's condition after transport was started - the incoming inspection - with ESA and the product assurance team from Astrium France: ASEF PA. The inspection of the secondary mirror M2 and its support structure (barrel and hexapod legs) was completed the same day without problems.
Inspection continued 30 January for the primary mirror M1 with participation of the product assurance team from Astrium Germany (ASED PA). The telescope was secured overnight with its optical axis horizontal in the locked cleanroom.