SPACE – The James Webb Space Telescope, scheduled for launch in 2018, is NASA's next big thing, and the planned replacement for the famous Hubble Space Telescope. Big, expensive, and ambitious, the telesope is exactly all that, but why does NASA need it?
Since it's launch in 1990, the Hubble Space Telescope has changed the way we look at the universe by providing us with data and images one simply cannot obtain from an earth-based telescope; it's most famous image, the Hubble Ultra-Deep Field, captured light which was 13 billion years old, and showed us some of the earliest galaxies in our universe. Today though, the gears are set in motion to create a new space telescope; one which will dwarf the Hubble in both size and scope; The James Webb Space Telescope.
The Hubble Ultra-Deep Field. Nearly every visible point of light in the image is a galaxy
The James Webb Space Telescope (JWST) has been under planning since 1996. Its development has been wrought with delays and budget increases; initially planned for a 2007 launch costing 0.5 billion USD, the project is currently planned for a 2018 launch, and the cost has soared to 8.7 billion USD. There were also talks of cancelation in 2011, but the project survived, thankfully. With the space shuttle fleet grounded, the JWST represents one of the last big space missions for NASA.
Size comparison between the Hubble and JWST collecting areas
A number of features set the telescope apart from it's older brother, the Hubble. Perhaps the most striking difference is that though the James Webb has approximately half the mass of the Hubble, the collecting area on the telescope is more than five times larger, totaling 25 m2, compared to Hubble's 4.5 m2. The collecting area is composed of a honeycomb structure of 18 gold-coated hexagonal mirror segments (the Hubble used a single mirror). The larger collecting area means the telescope can take in more light, and thus see deeper into the universe.