29 August 2005Preparations for the testing of the Payload Module in the Large Solar Simulator are continuing. The PLM will eventually house all the instruments and the cryogenic tank for cooling the detector plane to a few Kelvin. The PLM cryostat itself is flight hardware, currently containing science payload focal plane unit (FPU) mass and thermal dummies. The PLM will undergo a series of environmental qualification tests in the months to come
Each of the three heat shields intercept conducted and radiated heat from their warmer environment and are cooled by the gaseous helium boiling off from the superfluid helium (He II) tank or from the normal liquid helium tank.
The Herschel telescope assembly is also in the process of undergoing warm alignment in the facilities of EADS Astrium in Toulouse. After alignment and measurements under room temperature conditions, the telescope will undergo warm (it is launched warm) vibration tests, later to be followed by cryogenic measurements to verify optical performance under operational conditions.