Herschel Flight Model Arrives at ESTEC
8 January 2008The Herschel Flight Model (FM) spacecraft has arrived at ESTEC where it will undergo testing during the coming months. Currently the FM comprises the Service Module and the Cryostat Vacuum Vessel.
Yesterday, two days after its arrival on Saturday 5 January, the spacecraft was lifted out of its transport container and fastened to its Multi Purpose Trolley in the cleanroom. Preparations are underway with the electrical setup for the upcoming functional testing of the spacecraft to verify the spacecraft's condition after transport.
For the cryostat the immediate next step is the bake out during which the helium cooling system (which is not yet filled with helium) and the multi-layer insulation (MLI) is warmed to 60-70 °C with a vacuum pump attached to the cryostat. The main result of this is the removal of water from the system. The MLI is located between the cryostat's three internal thermal shields to allow them to maintain three separate temperatures during operations. Removing water molecules from the MLI improves its performance.
Later this month the telescope and the solar array will also arrive at ESTEC to be integrated with the Flight Model spacecraft.