JAMES WEBB SPACE TELESCOPE

 

JAMES WEBB SPACE TELESCOPE (J W S T)

     The J W S T  Was launched on December 25, 2021on an E S A Ariane 5 rocket from Kourou, French Guiana, and is intended to succeed the Hubble space telescope. It is 100 times more powerful than Hubble telescope. The telescope is named after James E. Webb who was the administrator of N A S A from 1961 to 1968 during much of the Apollo programs. It is organized by European Space Agency, N A S A, Canadian Space Agency at a cost of 1000 crores U S Ds. Launching mass is 6161.4 k gs and its dimensions are 20.197m x 14.162m. Mission duration seems to be !0 years but is likely to be extended up to 20 years.

     JWST operates in a halo orbit, circling around a point in space known as the Sun-Earth L2 Lagrange point, approximately 1,500,000 km (930,000 mi) beyond Earth's orbit around the Sun. Its actual position varies between about 250,000 km (160,000 mi) and 832,000 km (517,000 mi) from L2 as it orbits, keeping it out of both Earth and Moon's shadow. By way of comparison, Hubble orbits 550 km (340 mi) above Earth's surface, and the Moon is roughly 400,000 km (250,000 mi) from Earth. Objects near this Sun-Earth L2 point can orbit the Sun in synchrony with the Earth, allowing the telescope to remain at a roughly constant distance with continuous orientation of its unique sunshield and equipment bus toward the Sun, Earth and Moon. Combined with its wide shadow-avoiding orbit, the telescope can simultaneously block incoming heat and light from all three of these bodies   and avoid even the smallest changes of temperature from Earth and Moon shadows that would affect the structure, yet still maintain uninterrupted solar power and Earth communications on its sun-facing side. This arrangement keeps the temperature of the spacecraft constant and below the 50 K (−223 °C; −370 °F) necessary for faint infrared observations.

     It will focus on four main areas, first light in the universe, assembly of galaxies in the early universe, both of stars and protoplanetary systems and planets (including the origin of life). The webb is primarily is an infra red telescope. So it sees light that in lower wavelength than what our eyes can see. Its larger light collection area means that it can peer further back into time than Hubble is capable of doing. Its great sensitivity will enable the identification and characterization of comets and other icy bodies in the outermost regions of solar system. The webb will be able to see what the universe looked like around quarter of a billion years (probably back to 100 million years) after the Big Bang when the stars and galaxies started to form. Webb has a reserve of fuel to keep it operational for 10 years or more.