How NASA simulates the violent forces of a rocket launch
To survive the trip to space, the Nancy Grace Roman Space Telescope must endure extreme centrifugal forces. Engineers at NASA’s Goddard Space Flight Center use a massive 120-foot centrifuge to spin telescope components at 7.1 Gs, recreating the intense physical demands of a heavy-lift launch.
The Outer Barrel Assembly (OBA) acts as the telescope's 'exoskeleton,' protecting sensitive instruments from stray light and temperature fluctuations. Because the complete assembly is too large to fit in the testing chamber, engineers must test it in two distinct parts: the 'house' (the shell section) and the 'stilts' (the support struts, also known as the 'elephant stand'). The shell is a baffled carbon-fiber tube with a honeycomb structure to reduce weight, while the struts connect this shell to the spacecraft bus.
The testing process is a highly controlled, multi-day operation. During static load testing, the two components are separated. To ensure the center of gravity is accurate, engineers use aluminum weights called mass simulators to mimic the missing parts of the spacecraft. Nearly 100 sensors are attached to the structure to monitor strain. The struts undergo six different orientations, and the shell section is kept in a separate clean room, wrapped in protective Kapton film to prevent contamination.
The most intense phase involves a 120-foot-diameter centrifuge. The hardware is attached to a hydraulic platform that rotates to simulate various launch loads. In the final, most demanding spin, the assembly rotates at 18.4 rpm, generating 7.1 Gs of force. At this velocity, the air at the edge of the centrifuge travels at 80 mph, while the speed along the ground exceeds 130 mph. Following these tests, the components will be reassembled and prepared for thermal vacuum and vibration testing in 2025.
Source: Preparing for Launch and Beyond: Testing Roman's Outer Barrel Assembly
