Beryllium is a unique material chosen for the mirrors of NASA’s James Webb Space Telescope. It's extremely strong but light in weight and maintains its shape even at cryogenic temperatures as found in deep space. Since the sensitivity of a space telescope such as the Webb is a function of its mirrors’ reflective areas, holding precise shapes in deep space helps capture light from distant galaxies.
The James Webb Space Telescope employs a primary mirror that's 21 ft., 4 in. (6.5 m) across. Functioning as a form of “silent partner,” the U.S. Department of Defense (DoD) has helped NASA procure the beryllium it needed for the massive space telescope and to capture light from sources light years away.
The shift from traditional glass-based mirrors to components based on materials such as beryllium, which the DoD uses in weapons systems and surveillance satellites, has extended NASA’s exploratory reach into the universe.
“Beryllium is a really good material for that,” said Payl Geithner, a deputy project manager for Webb based at Goddard Space Flight Center. “It's really stiff, and once it gets below about -300°F, it basically stops shrinking.”
The excellent temperature stability is essential for the effective operation of the Webb telescope (see figure). In addition, beryllium’s stiffness enables the massive mirror and space telescope to withstand the high shock and vibration levels during rocket launch.
To aid in the development of essential materials like beryllium for space and warfare systems, Executive Order 14017 from President Joseph Biden made it possible for the U.S. DoD to develop a strategic roadmap to increase domestic production of critical materials.
Deborah G. Rosenblum, the DoD’s assistant defense secretary for Nuclear, Chemical, and Biological Defense Programs, explains, “The U.S. cannot have a secure, reliable domestic supply chain without robust organic capabilities. It is critically important for the U.S.'s future economic security that we establish end-to-end, commercial-scale, domestic supply chains across numerous strategic materials supply chains.”