A latch that hadn’t closed properly has been identified as the cause of the anomaly that halted vibration testing of the James Webb Space Telescope in December.
At the committee meeting, Smith said the problem was tracked down to a latch designed to hold in place one of the wings of JWST’s primary mirror, which consists of 18 hexagonal segments. Those wings are folded into place to fit within the payload fairing of the Ariane 5 that will launch JWST, then deployed into place once in space. The latch, he said, consists of two plates with serrated teeth a few millimeters in size. “The thought is that the teeth, when they closed it, they didn’t quite seat,” he said. “So during the vibe [test], the teeth clapped together on the order of a millimeter or two, and that was what made the noise.”
Engineers were able to replicate the noise by placing the plates slightly out of alignment in the lab and subjecting them to similar vibrations, giving them confidence that was the cause of the anomaly.
I love how the Webb program manager also says that Webb is “on budget and on schedule.” That claim could only be true if you make believe that the budget was always $9 billion and the launch date was always supposed to be 2018 instead of the original $1 billion and 2011 launch date.
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