JAMES WEBB SPACE TELESCOPE (JWST)

The European Ariane 5 rocket launched NASA’s James Webb Space Telescope (JWST), the biggest and most powerful space telescope yet constructed, from French Guiana, on the northeast coast of South America.

It is the successor of the Hubble Telescope and most powerful infrared telescope of National Aeronautics and Space Administration (NASA).

It is designed to explore a period known as the Epoch of Reionization, which came after the dark ages that followed the big bang. The telescope will study the atmospheres of a wide diversity of exoplanets. It will also search for atmospheres like Earth’s, and for the signatures of key substances such as methane, water, oxygen, carbon dioxide, and complex organic molecules, in hopes of finding the building blocks of life.

Goals 

• Search for the first galaxies that formed after the Big Bang. 
• Determine how galaxies evolved from their earlier formation until now.
• Observe the formation of stars from the first stages to the formation of planetary systems.
• Measure the physical and chemical properties of planetary systems and investigate the potential for life in such systems

ORBIT 

• JWST will be finally placed in second Lagrange Point (L2).
• Webb’s orbit follows a special path around L2 that allows it to stay on Earth’s night side (directly ‘behind’ the Earth as viewed from the Sun) and track along with Earth while moving around the Sun. 
• As an infrared observatory, Webb must be protected from all bright, hot sources to see the faint heat signals of distant objects in the universe. Because Webb will always stay on Earth’s night side as it moves around the Sun, its orbit ensures that one side of its sunshield will continuously face the Sun, Earth and Moon to block their view from the telescope’s optics.

Features that make it special

• While looking away from the Sun, JWST features one huge mirror with a diameter of 21 feet (the height of a standard two-story structure) that will collect infrared light flowing in from the deep space. 
• It will be protected by a five-layer, tennis court-sized, kite-shaped sunscreen that will block the sun’s heat and maintain the exceptionally cold temperatures that the sensors are meant to work at.
• Temperatures on the sun-facing side may reach 110°C, while the temperature on the opposite side is kept at –200° to –230°C. 
• To detect the exceedingly weak heat signals from faraway galaxies, extremely low temperatures are required. 
• The mirror, as well as the sunscreen, are much too huge to fit inside any rocket. They were designed to be collapsible and would be unfolded in space.