James Webb Telescope

James Webb Space Telescope (JWST), also known as NextGeneration Space Telescope, is a space observatory and successor to Hubble Space Telescope (HST). Scheduled to be launched on-board Ariane 5 rocket from French Guiana in October 2018, JWST will help astronomers study about the formation of Solar Systems capable of supporting life on planets such as Earth, to the evolution of the Solar System.

The telescope will be positioned 1.5 million kilometres away from the Earth at the second Lagrange point (L2) and will revolve around the Sun.

JWST is being developed by Nasa in collaboration with the European Space Agency (ESA) and the Canadian Space Agency (CSA). Space Telescope Science Institute will operate the telescope.

JWST design, features and development

The observatory will have three components, which are the integrated science instrument module (ISIM), the optical telescope element (OTE), and the spacecraft element.

ISIM is similar to a car’s chassis that acts as a base for the engine and other components. OTE will collect the light generated from space and deliver to science instruments in the ISIM. The spacecraft element will consist of spacecraft bus and five-layer sunshield.

JWST comprises a mirror with a diameter of 6.5m with a sunshield the size of a tennis court, and is six times more capable than the Hubble Space telescope. It is designed to maintain under low temperatures of approximately -230°C.

Northrop Grumman was selected as Prime Contractor to complete the JWST’s sunshield deployment and flight structure.

Ball Aerospace was contracted to provide Wavefront Sensing & Control (WFSC) software for the JWST. WFSC software includes mathematical algorithms to align and phase the JWST’s 18 different 1.3m hexagonal primary mirror segments to function as a single monolithic mirror.

The integration of science instruments with JWST was completed in April 2014, with final super cold tests on them completed in October 2015. Integration work of 18 primary flight mirrors on the telescope structure began in November 2015. The acoustic and vibration tests on the telescope were completed at Goddard Space Flight Centre located in Greenbelt, Maryland, in March 2017.

JWST mission details

JWST observatory will help astronomers to compare the early galaxies to the existing spirals and ellipticals in order to understand how galaxies formed over billions of years. The telescope is designed to explore the first stars and galaxies that formed after the Big Bang. The wavelength of the JWST will range from 0.6µ to 28µ.

It will be able to see through large clouds of dust, which are not transparent to observatories such as Hubble. It will also gain a further insight into the atmospheres of extrasolar planets, and study objects within our own Solar System.

Instruments on-board JWST

The telescope will be equipped with four instruments including mid-infrared camera and spectrograph (MIRI), near-infrared spectrograph (NIRSpec), NIRCam near-infrared camera, and fine guidance sensor/near-infrared imager and slitless spectrograph (FGS/NIRISS).

MIRI was developed by European Space Agency (ESA), in partnership with the Nasa’s Jet Propulsion Laboratory (JPL). The instrument will be used for conducting research on distant stellar population, on intense star formation regions, hydrogen emissions, the physical features of protostars, Kuiper Belt objects, faint comets, and to examine extra-solar planets.

"JWST observatory will help astronomers to compare the early galaxies to the existing spirals and ellipticals in order to understand how galaxies formed over billions of years."

Manufactured by ESA in association with Nasa’s Goddard Space Flight Center (GSFC), the NIRSpec instrument will be capable of obtaining a spectrum of more than 100 objects such as galaxies or stars. NIRSpec helps to learn about the formation of stars, galaxies, chemical elements and the intergalactic medium.

NIRCam manufactured by University of Arizona is intended for performing imaging studies and for observing faint objects. The camera’s prime role is to look for first stars, star clusters and galaxy cores that formed after the Big Bang.

FGS/NIRISS instrument was developed by the Canadian Space Agency and will be used for obtaining high-quality images from all the objects within its large field of view.

Launch vehicle details

The James Webb Space Telescope will be launched on an Ariane 5 ECA rocket manufactured by Arianespace from Guiana Space Centre, Kourou, French Guiana. The launch vehicle will have a total weight of 780t at lift-off and a height of 54.8m.