Model of the James Webb Space Telescope

Model of the James Webb Space Telescope

Credit: SPACE.com/Nola Taylor Redd

A 1/20th scale model of the James Webb Space Telescope sits at the Northrop Grumman Aerospace Systems office in Redondo Beach, Calif.

JWST Program Manager Scott Willoughby

JWST Program Manager Scott Willoughby

Credit: SPACE.com/Nola Taylor Redd

JWST Program Manager Scott Willoughby discusses the construction milestones of the ambitious space observatory.

JWST's Bus

JWST's Bus

Credit: SPACE.com/Nola Taylor Redd

JWST's 10-foot-wide bus contains the spacecraft's instruments and engines.

Structures of JWST Main Body

Structures of JWST Main Body

Credit: SPACE.com/Nola Taylor Redd

JWST Program Manager Scott Willoughby shows off the different structures of the main body of the James Webb Space Telescope.

JWST's Reinforced Bus

JWST's Reinforced Bus

Credit: SPACE.com/Nola Taylor Redd

JWST's bus is reinforced to withstand the stresses of its journey into space. "A lot of what goes into the structural design is surviving the launch," said JWST Program Manager Scott Willoughby.

JWST Bus

JWST Bus

Credit: SPACE.com/Nola Taylor Redd

JWST's bus is reinforced to withstand the stresses of its journey into space. "A lot of what goes into the structural design is surviving the launch," said JWST Program Manager Scott Willoughby.

One of the 18 JWST Mirrors

One of the 18 JWST Mirrors

Credit: SPACE.com/Nola Taylor Redd

An example of one of the eighteen hexagonal mirrors that JWST will carry. The final mirrors will have a thin coat of gold to increase their reflectiveness.

JWST Mirrors

JWST Mirrors

Credit: SPACE.com/Nola Taylor Redd

Scott Willoughby, Northrop Grumman's program manager for JWST, explains that the final mirrors were tested in groups of six.

The Sunshield of JWST

The Sunshield of JWST

Credit: SPACE.com/Nola Taylor Redd

The largest part of the James Webb Space Telescope is the five-layer sunshield, which measures 69.5 feet by 46.5 feet (22 by 12 meters) when extended.

Replica of the Sunshield

Replica of the Sunshield

Credit: SPACE.com/Nola Taylor Redd

A space-ready replica of the sunshield is extended. Each layer is either 1- or 2-thousandths of an inch thick.

10,000 inches of Seams

10,000 inches of Seams

Credit: SPACE.com/Nola Taylor Redd

The ridged structure of one of the 10,000 inches of seams that help the sunshield on the JWST maintain a 3D shape rather than lie flat.