|
||
|
EADS Astrium Completes Integration of World's Largest Space Telescope |
||
|
PARIS, Sept. 26, 2005/Satnews Daily/ — After four years work, EADS Astrium revealed it has successfully completed mechanical tests on the world's largest space telescope made of silicon carbide. EADS said the Herschel telescope is now on the way to the "Centre Spatial de Liège" (Belgium) for final thermal tests.
With a primary mirror diameter of 3.5m, Herschel is the largest space telescope ever constructed compared to Hubble's, which only has 2.4m wide primary mirror. The huge scale of the telescope is a direct result of scientists wanting the best possible images - in simple terms, the larger the mirror's diameter, the greater the amount of light that is collected and the higher the resolution of the images. The size of the Herschel telescope is in fact limited by the launcher fairing - at a maximum 3.5m, EADS said.
Following polishing of the primary mirror by Opteon (Finland), coating was carried out at the Calar-Alto Observatory (Spain), and the mirror was delivered for integration in June.
Integration consisted of accurately aligning the primary and secondary mirrors to achieve perfect optical quality. The precision adjustments required an accuracy greater than 5 microns. This accuracy was obtained using a seismic block, and an original auto-collimation method based on liquid mirrors. This was achieved towards the end of the summer, enabling excellent optical performance in line with the original objectives.
The optical performance achieved under clean room conditions must be maintained during the mission. The telescope therefore has to undergo a series of mechanical and thermal tests to simulate launch and orbit conditions, as repair in space is impossible.
This qualification phase, where the telescope was subjected to simulated acoustic and vibration launch conditions was completed successfully at the Intespace facilities in Toulouse, France, in mid September. Despite enduring 10 times the force of gravity, the telescope maintained its initial alignments, as well its optical quality.
The telescope is now en route to the "Centre Spatial de Liège" (Belgium), where it will undergo a series of thermal qualification tests to minus 200°C to ensure that optical quality is maintained. These tests are expected to be completed by the end of November.
Recent Stories: EADS Astrium Reports Success of Media Back-Link Trials from HMS Cumberland SES Astra Awards Astra 1M Satellite Contract to EADS Astrium |
||
