REDONDO BEACH, Calif. NASA's James Webb Space Telescope is one of the most intricate and powerful observatories ever devised.

Almost immediately after launching into space in 2018, James Webb Space Telescopewill begin the slow process of unfolding from its clamshell configuration into the most sensitive infrared instrument of its kind yet built. The telescope will then begin peering deep into the cosmos for signals left over from the Big Bang that created our universe.

But JWST's nail-biting deployment won't be the first time the craft unfolds. Before constructing the final components, engineers have been making sure to test and retest mockups in conditions potentially harsher than the telescope the long-awaited $8.8 billion successor to NASA's iconic Hubble Space Telescope will experience.

Space-ready drafts of the mirrors, solar shields and electronics-bearing body of the craft have been fabricated by the Northrop Grumman Corporation, NASA's primary contractor in charge of building JWST. [Photos: The James Webb Space Telescope]

Each piece is identical to the final product. The pieces of the giant telescope are exposed to the some of the worst trials engineers can come up with. The mockups must perform not only in ideal circumstances, but also in subpar conditions.

"You don't just test how it's going to work the way it's supposed to work," Scott Willoughby, JWST's program manager at Northrop Grumman, said during a Jan. 11 tour of the company's facility here in Redondo Beach.

Built in stages

The jet-sized telescope isn't being built all at once, but instead incrementally, allowing for testing of the individual parts.

"You don't built it all and see if it works," Willoughby said.

The first priority has been high-risk objects such as the mirrors and the instruments. JWST contains 18 hexagonal mirrors in an array, rather than one large mirror.

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NASA's Next Space Telescope Coming Together, Piece by Piece