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NASA's James Webb Space Telescope: Hubble's Cosmic Successor

NASA's James Webb Space Telescope, scheduled for launch in 2018, will probe the cosmos to uncover the history of the universe from the Big Bang to alien planet formation and beyond.

Scientists are planning to use the infrared telescope to search for the first galaxies that formed at the beginning of the universe. The James Webb Space Telescope (JWST) will also have the ability to look through cosmic dust clouds to find newly forming planetary systems and seek out the chemical origins of life in the solar system.

The powerful $8.8 billion spacecraft is also expected to take amazing photos of celestial objects like its predecessor, the Hubble Space Telescope. [How the James Webb Space Telescope Works (Infographic)]

Instruments on board

The JWST will come equipped with four science instruments.

  • Near-Infrared Camera (NIRCam) — Provided by the University of Arizona, this infrared camera will detect light from stars in nearby galaxies and stars within the Milky Way. It will also search for light from stars and galaxies that formed early in the universe's life. NIRCam will be outfitted with coronagraphs that can block a bright object's light, making dimmer objects near those stars (like planets) visible.
  • Near-Infrared Spectrograph (NIRSpec) — NIRSpec will observe 100 objects simultaneously, searching for the first galaxies that formed after the Big Bang. NIRSpec was provided by the European Space Agency with help from NASA's Goddard Space Flight Center.
  • Mid-Infrared Instrument (MIRI) — MIRI will produce amazing space photos of distant celestial objects, following in Hubble's tradition of astrophotography. The spectrograph that is a part of the instrument will allow scientists to gather more physical details about distant objects in the universe. MIRI will detect distant galaxies, faint comets, forming stars and objects in the Kuiper Belt. MIRI was built by the European Consortium with the European Space Agency and NASA's Jet Propulsion Laboratory.
  • Fine Guidance Sensor/Near InfraRed Imager and Slitless Spectrograph (FGS/NIRISS) — This Canadian Space Agency-built instrument is more like two instruments in one. The FGS component is responsible for keeping the JWST pointed in exactly the right direction during its science investigations. NIRISS will scope out the cosmos to find signatures of the first light in the universe and seek out and characterize alien planets.

The telescope will also sport a tennis court-size sunshield and a 21.3 foot (6.5 meter) mirror — the largest mirror ever launched into space. Those components will not fit into the rocket launching the JWST, so both will unfurl once the telescope is in space.

Infrared: Inside the huge space observatory that operates from a point in space four times further away than the moon.
NASA's James Webb Space Telescope is an $8.8 billion space observatory built to observe the infrared universe like never before. See how NASA's James Webb Space Telescope works in this Space.com infographic
Credit: Karl Tate, SPACE.com Infographics Artist

James Webb the man

The JWST is named for former NASA chief James Webb. Webb took charge of the space agency from 1961 to 1968, retiring just a few months before NASA put the first man on the moon.

Although Webb's tenure as NASA administrator is most closely associated with the Apollo moon program, he is also considered a leader in space science. Even in a time of great political turmoil, Webb set NASA's science objectives, writing that launching a large space telescope should be a key goal of the space agency. [See Photos of JWST, Hubble's Successor]

NASA launched more than 75 space science missions under Webb's guidance. They included missions that studied the sun, stars and galaxies as well as space directly above Earth's atmosphere.

Budget boondoggle

JWST's road to launch has been a bumpy one. Originally scheduled for launch in 2014, the space telescope was initially expected to cost about $5 billion, but due to budget constraints, technical setbacks and postponements, the space telescope's launch is now four years delayed and more than $3 billion over budget. However, NASA has said that everything is now on track for a 2018 launch date.

— Miriam Kramer, SPACE.com Staff Writer

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