In 2021 Humanity will see 13 billion years into the past. In a time machine has nothing to do with it. What are the most expensive project in the history of Space exploration the James Webb Space Telescope (JWST) or just Webb will help us to see the universe as it was shortly after the Big Bang theory.


Compared to its predecessor old man Hubble the Hubble space telescope. It is what a digital microscope is a magnifying glass so what amazing secrets will be discovered with it and how might our ideas about the world radically change. This project is be no means if brainchild of just the past few years for the past quarter century it is being to life by experts from NASA Canada and Europe. It was named after the second head NASA James Webb. James Webb headed the office space affairs from 1961 to 1968 and supervised the United States first manned launches into space the new telescope was first planned for launch into orbit in 2007 but has since been delayed more than once. Now it is being scheduled for late 2021 on that day James Webb join the Hubble space telescope to perform tasks including the creation of a 3D model of our universe.
After 2030 the Hubble will go on a well deserved rest since it's launch in 1990 it is provided more than a million images of thousands of stars nebulas planets and  galaxies of these is picture of the UDFJ-39546284 galaxies located 13.4 billion light years from earth that is the Hubble captured images of stars that's about 380 million years after the big bang which supposedly happened 13.7 billion years ago well these objects may no longer exist we still see their light. Some of the Hubble's image include stars up to 10 light years away from us which we observe in their exact form from 10 years ago. Now we expect James web to show us the universe as it was only 100 to 250 million years after its birth this will not only helps scientists to understand the processes that took place at that time but perhaps also transform our current understanding of the structure of the universe additionally the James Webb Space Telescope will be able to observe planets and their satellites found outside to our solar system and learn a lot about earth like eco planets for example we will be able to determine their density and analyse the composition of their atmospheres. In order to understand what type of objects the planet is and whether there is life or on it the Spitzer Space Telescope and SST and Hubble Space Telescope have collected data on the gas shells of about a hundred planets according to experts the James Webb is capable of exploring the atmosphere of more than 300 different exoplanets.
So, how does it work....
James Webb Space Telescope is an orbiting infrared observatory that will investigation the thermal radiation of space objects remember all solids and liquids when heated to a certain temperature exist energy in the infrared spectrum. Here, there is relationship between wavelength and temperature the higher the temperature the shorter the wavelength and the higher the radiation intensity.

The JWST weighs about half the weight of the Hubble Space Telescope, but with its main mirror, the 6.5-meter gold-plated beryllium sign will have a collection space more than six times, 25.4 square meters (273 sq ft), using a hexagon 18 mirrors with 0.9 square meters (9.7 sq ft) in the privacy of the supporting accessory straps.
Ground-based telescopes have to look at the earth's atmosphere, which is not visible to most infrared groups (see the number of air absorbers). Even when the atmosphere is clearly visible, most of the intended chemical elements, such as water, carbon dioxide, and methane, are also present in the earth's atmosphere, a very complex analysis. Existing space telescopes such as Hubble cannot study these belts as their mirrors are cool enough (the Hubble screen is kept at about 15 ° C (288 K)) so the telescope itself emits solid in the infrared groups. 

JWST will operate near Earth - Sun L2 (Lagrange point), approximately 1,500,000 kilometers (930,000 mi) across the Earth's orbit. By comparison, Hubble orbits 550 kilometers (340 mi) above the earth's surface, and the Moon is about 400,000 kilometers (250,000 mi) from Earth. This level has made repairs or upgrades to JWST hardware almost impossible for spacecraft available during the construction of the telescope and on the operating stage. SpaceX says its new Starship has the ability to bring satellites and a space telescope larger than James Webb and is designed to reach the Mars orbit. The objects near the Lagrange point can orbit the Sun in relation to the Earth, allow the telescope to remain at a constant distance and use a single solar shield to block heat and light from the Sun and Earth. This arrangement will keep the spacecraft temperature below 50 K (-223.2 ° C; -369.7 ° F), required for infrared monitoring. 
Spacecraft Bus is the main support base for the James Webb Space Telescope, which handles a wide range of computers, communications, explosives, and building components, bringing various telescope components together. Along with the sun shield, it forms the atmosphere of the space telescope. Two other major features of JWST are the Integrated Science Instrument Module (ISIM) and the Optical Telescope Element (OTE). ISIM Region 3 is also inside the Spacecraft Bus; Region 3 includes the ISIM Command and Data Handling system and the MIRI cryocooler.

The Spacecraft Bus is connected to the Optical Telescope Element via the Deployable Tower Assembly, which also connects to solar panels.

The Spacecraft Bus building weighs 350 kg (approximately 770 lb), and should support 6.5 tons of space telescope.It is made mainly of composite graphite materials. It was assembled in California, the convention was completed in 2015, and then had to be integrated with the rest of the space telescope which led to its planned launch in 2021. The bus can provide precision tracking of one arcsecond, and split vibration into two milliarcseconds.

The Spacecraft Bus is on the "warm" side of the Sun and operates at a temperature of approximately 300 K. Everything on the Sun's side must be able to handle the hot conditions of the JWST halo orbit, one side in the continuous sun and the other in the shadow of the sun of the spacecraft.

Another important feature of the Spacecraft Bus is the central computer, memory storage, and communication equipment. The processor and software directs data to or from musical instruments, to the context, and to a radio program that can send data back to Earth and receive instructions. The computer also controls the timing of a spacecraft, captures sensor information in gyroscopes and a star tracker, and sends the necessary instructions to turn wheels or thrusters.