The FINANCIAL -- Cryogenic testing is complete for the final six
primary mirror segments and a secondary mirror that will fly on NASA's
James Webb Space Telescope.
The milestone represents the successful culmination of a process that took years and broke new ground in manufacturing and testing large mirrors.
The Webb telescope has 21 mirrors, with 18 mirror segments working together as a large 21.3-foot primary mirror. Each individual mirror segment now has been successfully tested to operate at 40 Kelvin.
Completed at the X-ray and Cryogenic Facility at NASA's Marshall Space Flight Center in Huntsville, Ala., a ten-week test series chilled the primary mirror segments to -379 degrees Fahrenheit. During two test cycles, telescope engineers took extremely detailed measurements of how each individual mirror's shape changed as it cooled. Testing verified each mirror changed shape with temperature as expected and each one will be the correct shape upon reaching the extremely cold operating temperature after reaching deep space.
Ball Aerospace and Technologies Corp. in Boulder, Colo. successfully completed comparable testing on the secondary mirror. However, because the secondary mirror is convex, it does not converge light to a focus. Testing the mirror presented a unique challenge involving a special process and more complex optical measurements.
The Webb telescope is the world's next-generation space observatory and successor to the Hubble Space Telescope. It will be most powerful space telescope ever built, provide images of the first galaxies ever formed, and explore planets around distant stars. It is a joint project of NASA, the European Space Agency and the Canadian Space Agency.
Related Stories
