Northrop Grumman has completed the flight composite components for the structure that connects the Optical Telescope Element to the spacecraft on NASA's James Webb Space Telescope. Northrop Grumman is under contract to NASA's Goddard Space Flight Center in Greenbelt, Md. for the design and development of Webb's sunshield, telescope and spacecraft.

The flight structure known as the Deployable Tower Assembly (DTA) is designed by Northrop Grumman's business unit Astro Aerospace and is a telescoping tower primarily comprised of composite components fabricated by Webb teammate ATK.

The DTA deploys after launch, raising the cold telescope off the warm spacecraft bus, and is a key component of JWST's passive cooling architecture.

Passively cooling the telescope to cryogenic temperatures avoids using limited-life cryogenic liquid coolants. Made of lightweight graphite composite material chosen for its ability to thermally insulate the cold telescope from the hot spacecraft, the tower assembly extends to nearly twice its stowed height, from 1.7 meters (5.6 feet) to 2.9 meters (9.6 feet) once it is deployed.

"ATK's completion of the deployable tower assembly composite components marks another flight hardware milestone in the fabrication of one of the most significant structures that supports the telescope's optical train," said Scott Texter, Webb Optical Telescope Element manager, Northrop Grumman Aerospace Systems.

"These parts were very difficult to fabricate, involving some complex geometries, and ATK did a commendable job."

The tower includes deployable harness trays for the electronics and refrigerant cables that run to the cryocooler, which keeps the Mid-Infrared Instrument at ultra cold temperatures.

The 5.9 meters (19.6 feet) of electronics cables are attached to a Z-folded cable-tray structure that unfolds. The cryocooler line is a high-tech "slinky" that uncoils as the DTA extends, via a complex drive mechanism inside the tubes that pushes them apart.

Successor to the Hubble Space Telescope, the James Webb Space Telescope is the world's next-generation space observatory. It will be the most powerful space telescope ever built. Webb will observe the most distant objects in the universe, provide images of the very first galaxies ever formed and study planets around distant stars.