James Webb space telescope completes first round of cryogenic mirror test

June 17, 2011 By Kimberly Newton
Engineers and technicians guide six James Webb Space Telescope’s mirror segments off the rails after completing final cryogenic testing this week at Marshall. Credit: NASA/Emmett Given

The first six of 18 segments that will form NASA's James Webb Space Telescope’s primary mirror for space observations completed final cryogenic testing this week. The ten week test series included two tests cycles where the mirrors were chilled down to -379 degrees Fahrenheit, then back to ambient temperature to ensure the mirrors respond as expected to the extreme temperatures of space.

A second set of six assemblies will arrive at Marshall in late July to begin testing, and the final set of six will arrive in the fall.

The X-ray and Cryogenic Facility at NASA's Marshall Space Flight Center in Huntsville, Ala. provides the space-like environment to help engineers measure how well the telescope will image infrared sources once in orbit.

Engineers ready the crane to lift one James Webb Space Telescope’s mirror segment off the stand after completing final cryogenic testing this week at Marshall. Credit: NASA/Emmett Given

Each mirror segment measures approximately 4.3 feet (1.3 meters) in diameter to form the 21.3 foot (6.5 meters), hexagonal telescope mirror assembly critical for infrared observations. Each of the 18 hexagonal-shaped mirror assemblies weighs approximately 88 pounds (40 kilograms). The mirrors are made of a light and strong metal called beryllium, and coated with a microscopically thin coat of gold to enabling the mirror to efficiently collect infrared light.

The telescope is a combined project of , the European Space Agency and the Canadian Space Agency. Northrop Grumman is the prime contractor under NASA's Goddard Space Flight Center in Greenbelt, Md. Ball Aerospace & Technologies Corp. in Boulder, Colo., is responsible for mirror development. L-3- Tinsley Laboratories Inc. in Richmond, Calif. is responsible for mirror grinding and polishing.

Explore further: James Webb Space Telescope Completes Cryogenic Mirror Test

Related Stories

Two kinds of Webb telescope mirrors arrive at NASA Goddard

April 13, 2011

It takes two unique types of mirrors working together to see farther back in time and space than ever before, and engineers at NASA's Goddard Space Flight Center have just received one of each type. Primary and Secondary ...

NASA's next generation space telescope marks key milestone

April 15, 2011

(PhysOrg.com) -- The first six of 18 segments that will form NASA's James Webb Space Telescope's primary mirror for space observations will begin final round-the-clock cryogenic testing this week. These tests will confirm ...

Recommended for you

New Horizons team selects potential Kuiper Belt flyby target

August 29, 2015

NASA has selected the potential next destination for the New Horizons mission to visit after its historic July 14 flyby of the Pluto system. The destination is a small Kuiper Belt object (KBO) known as 2014 MU69 that orbits ...

Dawn spacecraft sends sharper scenes from Ceres

August 25, 2015

The closest-yet views of Ceres, delivered by NASA's Dawn spacecraft, show the small world's features in unprecedented detail, including Ceres' tall, conical mountain; crater formation features and narrow, braided fractures.

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

Eoprime
not rated yet Jun 21, 2011
Could we please use SI-Units? Kelvin/degree Celsius?
Degree fahrenheit is an ugly arbitrary unit.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.