How to achieve nanometer precision in space?
What it is
Breaking Taps explains how the cryogenic mirror actuators on the James Webb Space Telescope achieve nanometer precision using flexures. It shows a 3D-printed replica and how one motor handles both coarse and fine motion.
Why Hacker News recommends it
Commenters repeatedly recommend it in JWST threads as a great explanation of clever mechanical design that is accurate and long lasting.
- 4 people recommended it
- 3 different months
- 1 strong recommendations
- first 2022, last 2026
What HN commenters said
“I highly recommend”
Explains JWST flexure actuators with a 3D-printed replica
infogulch, 2022-03 · Strong recommendation · in “First images from James Webb telescope exceed expectations”
“Here a nice video that explains the mechanism that aligns each mirror”
Explains how one motor aligns each JWST mirror segment
blenderdt, 2022-03 · Recommendation · in “First images from James Webb telescope exceed expectations”
“It's a great watch and shows how well thought out design can produce accurate and long lasting parts.”
Shows how JWST actuators achieve accuracy and longevity
mywacaday, 2022-03 · Recommendation · in “Mars helicopter Ingenuity completes 22nd flight”
“there's a great youtube video explaining how the actuators to align the James Webb mirrors work”
Explains JWST mirror actuators and offers a 3D printable version
bigiain, 2026-01 · Recommendation · in “The (likely?) cheapest home-made Michelson interferometer”
Excerpts from Hacker News comments, linked to the originals. Summaries and labels were written by a language model from those comments.
Topics: jwst, flexures, actuators, mechanical engineering, cryogenics
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