An Inside Glimpse of the World’s Biggest Space Telescope

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Image: Ball Aerospace
Cryogenic testing being performed on the telescope’s flight mirrors at NASA’s Marshall Space Flight Center in Alabama

We may not be able to travel back in time, but once the currently-under-construction James Webb Space Telescope (JWST) is completed, we’ll be able to see 13 billion light years into space! That’s far enough back to witness the creation of the universe’s first stars and galaxies! To achieve this, an extraordinary instrument is needed; in fact, no less than what, come 2018, will be the biggest telescope ever sent into orbit.


Image: NASA/MSFC/David Higginbotham/Emmett Given
Ball Aerospace’s Jake Lewis inspects the mirrors in NASA’s X-ray and Cryogenic Facility for Testing.

The JWST is the successor to two previous telescopes: the Hubble Space Telescope and the Spitzer Space Telescope. About 17 countries – led by NASA with assistance from the European and Canadian space agencies – have been working on the project since 1996. The final telescope will cost $8 billion – which even taking into account inflation is twice as expensive as the Hubble Telescope cost by the time it was launched into Earth’s orbit in 1990. In fact, in 2011 the JWST was almost cancelled for being too expensive, but fortunately funding was resumed, and the gigantic telescope will now be launched in 2018.

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Image: NASA/Ed Campion
A full-scale model of the James Webb Space Telescope, located at the Maryland Science Center in Baltimore

The physical proportions of the JWST will be suitably enormous. For one, this gigantic undertaking incorporates a 21-foot (6.5-meter) diameter mirror with a tennis court-sized sunshield. The mirror is made up of 18 hexagonal segments, each of them four feet (1.3 meters) in diameter, made of beryllium coated with gold, and polished to a high shine.

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