Milestone Reached in Sunshield for James Webb Space Telescope

September 20th, 2013

The James Webb Space Telescope will be pointed so that the Sun, Earth and Moon are always on one side, and the sunshield will act like a parasol, keeping the optics and science instruments cool by keeping them in the shade and protecting them from the heat of the sun and warm spacecraft electronics. Credit: Northrop Grumman Corp.

Technicians at Northrop Grumman's Space Park facilities in Redondo Beach, Calif., are conducting tests to ensure the Webb Telescope’s sunshield membrane layers meet flight performance requirements. Credit: Northrop Grumman Corp.

More progress has been reported in the James Webb Space Telescope program, the world’s next-generation space observatory and successor to the Hubble Space Telescope.

The fabrication of all template layers for NASA’s James Webb Space Telescope (JWST) sunshield has been completed. The template layers are the last step before making the final JWST flight sunshield layers.

The tennis-court sized sunshield is needed to separate the observatory into a warm sun-facing side and a cold anti-sun side.

The design and development of the Webb Telescope’s optics, sunshield and spacecraft is under the auspices of Northrop Grumman Corporation.

NeXolve is subcontractor to Northrop Grumman to manufacture the one-of-a-kind sunshield membranes. NeXolve is a subsidiary of ManTech International Corporation based in Huntsville, Alabama.

Unfolding drama

The JWST project is working to a 2018 launch date.

Webb will have a large mirror, 21.3 feet (6.5 meters) in diameter. Both the mirror and sunshade won’t fit onto a rocket fully open, so both will fold up and open once Webb is in outer space.

Webb will reside in an orbit about 1 million miles (1.5 million kilometers) from the Earth.

Once on duty, the Webb Telescope will primarily observe infrared light from faint and very distant objects. And in order to detect infrared light, the optics must be cold.

The pioneering sunshield passively cools the telescope to a temperature of -375 degrees F, preventing the observatory’s own heat from “blinding” its infrared sensing instruments.

Never been done before

Technicians at Northrop Grumman are also practicing folding and unfolding the five layers of the sunshield by hand on a test bed.

Sunshield tests and processes are critical to the project and provide confidence that fabricating the final flight layers can be executed, said Jim Flynn, Webb sunshield manager at Northrop Grumman Aerospace Systems.

“We have to take a step back and remember that this has never been done before,” Flynn said, “so we need to build confidence that what we’re innovating and designing will work.”

The most powerful space telescope ever built, the Webb Telescope will observe the most distant objects in the universe, provide images of the first galaxies formed and see unexplored planets around distant stars.

The Webb Telescope is a joint project of NASA, the European Space Agency and the Canadian Space Agency. NASA’s Goddard Space Flight Center in Greenbelt, Maryland is managing the JWST project.

By Leonard David