Mechanical tests on the Herschel flight model spacecraft were successfully completed on 3 July 2008. On that day, the last vibration test was performed on the multi-axis hydraulic shaker at ESTEC. The spacecraft is currently undergoing electrical tests and will later be prepared for the forthcoming environmental tests scheduled for September.
The end of the mechanical test campaign marked a major milestone for the Herschel spacecraft. The mechanical tests included the acoustic tests inside the LEAF (Large European Acoustic Facility) and the vibration tests on several shakers at the ESTEC test facilities. Together they have verified that the Herschel spacecraft is compliant with specification requirements, ensuring that the flight model is ready for launch.
On 16 July 2008, following the last of the mechanical tests, the “M1/M2 distance measurements”, measurements that accurately measure the distance between the two mirrors of the Herschel telescope, were again performed to verify the optomechanical stability of the telescope. These measurements are always performed after completion of significant activities. For the M1/M2 distance measurements the spacecraft was tilted into a horizontal position.
The images show the Herschel spacecraft in the Hydra cleanroom at ESTEC after completion of the vibration tests where it is currently undergoing electrical tests of the different subsystems and instruments.
In several weeks time, the spacecraft will be transferred for installation in the Large Space Simulator (LSS), whilst the preparatory work has already started. There it will undergo the environmental testing with the LSS simulating the thermal vacuum conditions of space.
