The mission of NASA’s James Webb Space Telescope is to find the first galaxies that formed in the early universe and to see stars forming planetary systems. The telescope is scheduled for launch in 2021.

The Deployable Tower Assembly of NASA’s James Webb Space Telescope is a critical piece in the operation and support of the structure, playing a role in how the observatory deploys in space as well as serving to maintain safe operating temperatures by separating its mirrors from the Sun-facing side.

The Deployable Tower Assembly is made of graphite-epoxy composite material to provide the strength needed to deal with the extreme environmental conditions, including the temperature changes, that occur in space. The deployable structure resembles a thick black pipe and features two nested telescoping tubes. After the telescope is launched, the tower will deploy to separate the telescope mirrors and instruments from the spacecraft bus, keeping the telescope safe from vibrations and heat.

The structure recently achieved a successful deployment during the final post-environmental testing of the fully assembled telescope. The testing took place at Northrop Grumman’s Space Park in Redondo Beach, Calif. The tower will be deployed twice more before the launch. Once extended, each of the layers of the sunshield will be folded and secured with membranes protecting the device from the powerful rocket launch.

“Last month, the accelerometer responses during acoustic and sine-vibration testing and initial visual inspections were a rough guide to show Webb was operating properly. The proof comes in the post-environment Comprehensive Systems Test and the various deployments, including extending the Deployable Tower Assembly,” said Paul Geithner, Webb Deputy Project Manager – Technical at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.