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A major component of NASA\u2019s Nancy Grace Roman Space Telescope just took a spin on the centrifuge at NASA\u2019s Goddard Space Flight Center in Greenbelt, Maryland. Called the Outer Barrel Assembly, this piece of the observatory is designed to keep the telescope at a stable temperature and shield it from stray light.<\/p>\n
The two-part spin test took place in a large, round test chamber. Stretching across the room, a 600,000-pound (272,000-kilogram) steel arm extends from a giant rotating bearing in the center of the floor.<\/p>\n
The test itself is like a sophisticated version of a popular carnival attraction, designed to apply centrifugal force to the rider \u2014 in this case, the outer covering for Roman\u2019s telescope. It spun up to 18.4 rotations per minute. That may not sound like much, but it generated force equivalent to just over seven times Earth\u2019s gravity, or 7 g<\/em>, and sent the assembly whipping around at 80 miles per hour.<\/p>\n \u201cWe couldn\u2019t test the entire Outer Barrel Assembly in the centrifuge in one piece because it\u2019s too large to fit in the room,\u201d said Jay Parker, product design lead for the assembly at Goddard. The structure stands about 17 feet (5 meters) tall and is about 13.5 feet (4 meters) wide. \u201cIt\u2019s designed a bit like a house on stilts, so we tested the \u2018house\u2019 and \u2018stilts\u2019 separately.\u201d<\/p>\n The \u201cstilts\u201d went first. Technically referred to as the elephant stand because of its similarity to structures used in circuses, this part of the assembly is designed to surround Roman\u2019s Wide Field Instrument and Coronagraph Instrument like scaffolding. It connects the upper portion of the Outer Barrel Assembly to the spacecraft bus, which will maneuver the observatory to its place in space and support it while there. The elephant stand was tested with weights attached to it to simulate the rest of the assembly\u2019s mass.<\/p>\n Next, the team tested the \u201chouse\u201d \u2014 the shell and a connecting ring that surround the telescope. These parts of the assembly will ultimately be fitted with heaters to help ensure the telescope\u2019s mirrors won\u2019t experience wide temperature swings, which make materials expand and contract.<\/p>\n To further protect against temperature fluctuations, the Outer Barrel Assembly is mainly made of two types of carbon fibers mixed with reinforced plastic and connected with titanium end fittings. These materials are both stiff (so they won\u2019t warp or flex during temperature swings) and lightweight (reducing launch demands).<\/p>\n If you could peel back the side of the upper portion \u2013\u2013 the house\u2019s \u201csiding\u201d \u2013\u2013 you\u2019d see another weight-reducing measure. Between inner and outer panels, the material is structured like honeycomb. This pattern is very strong and lowers weight by hollowing out portions of the interior.<\/p>\n Designed at Goddard and built by Applied Composites in Los Alamitos, California, Roman\u2019s Outer Barrel Assembly was delivered in pieces and then put together in a series of crane lifts in Goddard\u2019s largest clean room. It was partially disassembled for centrifuge testing, but will now be put back together and integrated with Roman\u2019s solar panels and Deployable Aperture Cover at the end of the year.<\/p>\n In 2025, these freshly integrated components will go through thermal vacuum testing together to ensure they will withstand the temperature and pressure environment of space. Then they\u2019ll move to a shake test to make sure they will hold up against the vibrations they\u2019ll experience during launch. Toward the end of next year, they will be integrated with rest of the observatory.<\/p>\n To virtually tour an interactive version of the telescope, visit:<\/p>\n<\/p>\n The Nancy Grace Roman Space Telescope is managed at NASA\u2019s Goddard Space Flight Center in Greenbelt, Maryland, with participation by NASA\u2019s Jet Propulsion Laboratory and Caltech\/IPAC in Southern California, the Space Telescope Science Institute in Baltimore, and a science team comprising scientists from various research institutions. The primary industrial partners are BAE Systems, Inc in Boulder, Colorado; L3Harris Technologies in Rochester, New York; and Teledyne Scientific & Imaging in Thousand Oaks, California.<\/p>\n By Ashley Balzer<\/em><\/strong>
NASA\u2019s Goddard Space Flight Center<\/em><\/strong>, Greenbelt, Md.<\/em><\/strong><\/p>\n