“Once the mirror cell is transferred from the telescope on the fourth floor of the AEOS building to the mirror coating facility on the first floor, it takes about two weeks to remove the mirror substrate from the cell, strip off the old coating, and prepare the coating chamber,” Hunt said. Removing the primary mirror cell from the telescope and relocating it to the mirror recoating facility is a delicate and time-consuming process that ends in a rapid recoating of the mirror. These imperfections include stains, pinholes and splatter spots created by dust and contaminant on the mirror substrate or drips of aluminum at the time of coating.” Imperfections in the original coating increase scatter and decrease reflectivity and can accelerate degradation. “When the coating is first applied, it is approximately 1,000 Angstroms thick, or about 1/7th the width of a human hair. They weigh this against the risk of recoating, the telescope being out of service and mission performance for daytime imaging and dim object detection.ĭownload Hi-Res “The bare aluminum coating of the AEOS primary mirror degrades overtime,” Hunt said.

Hunt said scientists and engineers track the degradation of reflectivity and scatter of the mirror over time. Typically, our SDA objects are brighter than astronomical objects, and therefore we can push the coatings longer than the astronomers can.” “For our SDA mission, we have the challenge of detecting dim objects during the nighttime and performing imaging of satellites during the daytime.

“Large mirrors like the AEOS 3.6-meter should be recoated every 4 to 6 years, but performance requirements are highly dependent on the mission of the telescope,” said Scott Hunt, the site’s technical director. The long duration between the original coating and the first recoat was mainly driven by the construction of the mirror recoat facility, completed in 2008. The first mirror recoat occurred in late 2008, roughly 12 years after application of the original coating in 1997. There is never really a good time to take the telescope out of service, but it is better to plan the recoat as a periodic maintenance effort than having to shut down the telescope due to catastrophic mission degradation.” “Periodic recoating of the AEOS’s primary mirror ensures readiness of the telescope to support the SDA mission for the warfighter. “I am honored to lead both of these critical functions that preserve our access to and freedom to operate in space,” Wagenbach said. Phillip Wagenbach, who is both the squadron commander and branch chief of the AFRL Directed Energy Directorate’s research and development mission. Keeping the AEOS telescope’s primary mirror in quality condition is paramount to the site’s SDA mission, said Lt. AEOS is a reflector telescope, indicating it has a small secondary mirror placed near the prime mirror’s focus to reflect light through a central hole, increasing the magnification and sharpness of objects in the sky.

VIDEO | 06:45 | The Advanced Electro-Optical System (AEOS) telescope receives a recoatįollowing a year of planning and four months of execution, the site completed the recoating of the AEOS, the telescope’s primary mirror.

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