English: To test the James Webb Space Telescope’s readiness for its journey in space, technicians successfully commanded it to deploy and extend a critical part of the observatory known as the Deployable Tower Assembly.

The primary purpose of the deployable tower is to create a large gap between the upper part of the observatory that houses its iconic gold mirrors and scientific instruments, and the lower section known as the spacecraft bus which holds its comparatively warm electronics and propulsion systems. By creating a space between the two, it allows for Webb’s active and passive cooling systems to bring its mirrors and sensors down to staggeringly cold temperatures required to perform optimal science.

Read more: www.nasa.gov/feature/goddard/2020/tower-extension-test-a-...

Image: Shown fully stowed, the James Webb Space Telescope’s Deployable Tower Assembly that connects the upper and lower sections of the spacecraft will extend 48 inches (1.2 meters) after launch.

Credits: Northrop Grumman