James Webb Space Telescope Explained

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Table of Contents

Quick introduction

With the evolution of technology and science Space exploration got us  to the point where it  isn’t anymore SCI-FI but it’s a common field of science .Since the launch of the first satellite in 1957,  astronauts have traveled to the moon, probes have explored the solar system, and instruments in space have discovered thousands of planets around other stars. From the beginning of time humans have always looked up into the night sky and dreamed about space. Today the exploration of space is available thanks to the vast and rapid research of technology that gives us the opportunity to explore the secrets of the Universe.

Brief history of Space Exploration

Before talking about the mind-blowing futuristic Telescope that’s going to change completely the way we see the Universe, we are going to present you a brief history of Space Exploration so you can have an aspect of the magnitude of this Invention and its importance to us all .

After the launch of the Soviets first artificial satellite on Oct. 4, 1957, Sputnik 1, into space,it took just only four years after on the April 12,1961 to send the first human to orbit Earth in Vostok 1.His name was Yuri Gagarin and  was the first human in space. His vehicle, Vostok 1 circled Earth at a speed of 27,400 kilometers per hour with the flight lasting 108 minutes. Vostok’s reentry was controlled by a computer.

“One small step for man, one giant leap for mankind.”

These words marked the biggest step mankind ever took in the exploration of Space. The American effort to send astronauts to the moon had its origins in an appeal President Kennedy made to a special joint session of Congress on May 25, 1961: “I believe this nation should commit itself to achieving the goal, before this decade is out, of landing a man on the moon and returning him safely to Earth.” By making history The Americans sent the first Human ever to walk on the Moon . immediately after those happenings On July 20, 1969, American astronauts Neil Armstrong (1930-2012) and Edwin “Buzz” Aldrin (1930-) became the first humans ever to land on the moon. About six-and-a-half hours later, Armstrong became the first person to walk on the moon. They were a part of the Apollo exploration missions. Altogether six Apollo missions were made to explore the moon between 1969 and 1972.

The era of Orbital Deployment

By the early 1970s, orbiting communications and navigation satellites were in everyday use, and the Mariner spacecraft was orbiting and mapping the surface of Mars. By the end of the decade, the Voyager spacecraft had sent back detailed images of Jupiter and Saturn, their rings, and their moons. In the 1980s, satellite communications expanded to carry television programs, and people were able to pick up the satellite signals on their home dish antennas. Satellites discovered an ozone hole over Antarctica, pinpointed forest fires, and gave us photographs of the nuclear power plant disaster at Chernobyl in 1986. Astronomical satellites found new stars and gave us a new view of the center of our galaxy.

The Arrival of the Space Shuttle

At the beginning of the 1980s with the first launch of the Space shuttle Columbia sheered in a period of reliance on the reusable shuttle for most civilian and military space missions  .At the total of twenty-four successful launch missions were fulfilled m. Being the first reusable spacecraft to carry the people into orbit, launch and repair satellites the Space shuttle marked the evolution to space systems and machines .

The international Station(ISS)

The International Space Station (ISS) is a modular space station (habitable artificial satellite) that was sent to the low Earth orbit. is a multinational collaborative project involving five participating space agencies .The station has been continuously occupied since the arrival of Expedition 1 in November of 2000.

Reading the brief history of space exploration will help you better understand the James webb space telscope and about its capabilities and potential to change the way we see the Universe.

Why do Space Telescopes exist?

A space telescope or space observatory is a telescope in outer space used to observe astronomical objects. Suggested by Lyman Spitzer in 1946, the first operational telescopes were the American Orbiting Astronomical Observatory, OAO-2 launched in 1968, and the Soviet Orion 1 ultraviolet telescope aboard space station Salyut 1 in 1971.

Performing astronomy from ground-based observatories on Earth is limited by the filtering and distortion of electromagnetic radiation due to the atmosphere .A telescope orbiting Earth outside the atmosphere is subject neither to twinkling nor to light pollution from artificial light sources on Earth. As a result, the angular resolution of space telescopes is often much higher than a ground-based telescope with a similar aperture. Many larger terrestrial telescopes, however, reduce atmospheric effects with adaptive optics.

Being placed into orbit around the Earth or being send into space with the important mission to give a clearer view of the Universe .The Space Telescopes help scientists determine the temperature, chemical composition ,density and motion of objects in space that will help determine the answers of How the Universe started ,detecting space objects ,they especially helped in the detecting of Black Holes and many other things.

Before the launch of the James webb space telscope many space telescopes were in in active duty.To get a glimpse of this number we will answer you the question of How many space telescopes were placed into Orbit only By NASA and ESA, The astonishing number is 90.

Besides the fact that Space Telescopes are a proof of our engineering capabilities and research, they also very expensive to make.The price of the newer ones exceed almost always hundreds of millions.

James webb space telescope as one of the most important and iconic engineering projects ever

Why is the James webb space telescope so important?

NASA’s largest and most powerful space science telescope — will probe the cosmos to uncover the history of the universe from the Big Bang to alien planet formation and beyond. It is one of NASA’s Great Observatories, huge space instruments that include the likes of the Hubble Space Telescope to peer deep into the cosmos.

The James Webb Space Telescope is the next chapter in spaced-based telescope astronomy.

With the ability to detect light beyond the visible spectrum, into the mid-infrared range. Because infrared light travels through dense gas clouds that block visible light, Webb will reveal previously hidden regions of the universe: early galaxies, forming planets, brown dwarfs, and much more.

Being the largest telescope ever sent into space ,Webb’s innovative design tackles the two main challenges for an infrared telescope: it has to have a large mirror to best capture enough light; and it has to be kept cold to keep unwanted sources of infrared from interfering with the light being observed.

Undertaking one of the most complicated and sophisticated engineering projects on the World. The engineers that worked on this 25-year project have proven that we are one step closer to finding out the truth about the Universe and its beginning.

Design of the James Web telescope


The $10 billion Space Telescope innovative design tackles the two main challenges for an infrared telescope: it has to have a large mirror to best capture enough light; and it has to be kept cold to keep unwanted sources of infrared from interfering with the light being observed. Webb’s tennis court-sized sunshields protect it from stray heat and light from the Sun .JWST’s primary mirror consists of 18 hexagonal mirror segments made of gold-plated beryllium which combined create a 6.5-meter (21 ft) diameter mirror, compared to Hubble’s 2.4 m (7.9 ft). This gives the Webb telescope a light-collecting area about 25 square meters, about 6 times that of Hubble. Unlike Hubble, which observes in the near ultraviolet, visible, and near infrared (0.1–1.7 μm) spectra, JWST will observe in a lower frequency range, from long-wavelength visible light (red) through mid-infrared (0.6–28.3 μm). The telescope must be kept extremely cold, below 50 K (−223 °C; −370 °F), to observe faint signals in the infrared without interference from other sources of warmth. All these conditions must be met so it can effectively capture infrared light.



The initially cost planned for this telescope started at US$500 million budget. There were many delays and cost overruns ,but the biggest one was the major redesign in 2005.

Next to the redesign of the Telescope there were many more setbacks of the mission like  a ripped sunshield during a practice deployment, a threat by the U.S. Congress to cancel the project, the COVID-19 pandemic,[8] and problems with the telescope itself .Construction was completed in late 2016, followed by years of extensive testing before launch. The total project costed about US$9.7 billion.

The engineering marvel

Launching such a large mirror into space is a huge challenge? Or is it?

With the bright and creative thinking of our engineers who created and designed the telescope (The Goddard Space Flight Center-led team,Ball Aerospace, Lockheed Martin ,TRW) the problem of launching it and sending it to space was solved.

With the number of 344 “single-point failures,” JWST was one of the riskiest missions in history. Because the JWST is entirely too large to test everything in person, and testing on Earth isn’t the same as testing in space, engineers simulated how the telescope will act in its operational environment.

The Engineers used the most sophisticated simulation programs to see how the telescope will act in every situation .Some of the Systems and programs used are  Systems Tool Kit’s (STK) Astrogator capability from AGI, an Ansys company, to build complex design reference missions (DRMs). To model the pressure of the light from the Sun on the large Sun shield deployed on JWST, they used the custom solar radiation pressure (SRP) plugin point in ODTK to insert a proprietary model into ODTK’s advanced estimation algorithms .For Mirror pointing they used  Ansys Mechanical simulations to identify solutions to the precise mirror pointing given the natural vibrational frequencies of the structures. Mechanical helped determine the effects of having a connected, segmented mirror .For the Alignment of the mirrors the Ansys Zemax  software was used to  simulate the  complex optics of the numerous individual gold-plated mirror segments in the telescope. The 18 hexagonal segments of JWST’s primary mirror function as a single mirror, with a surface smoother than 100 nanometers. Engineers used Zemax software to design and test every step of the alignment process, from the initial segment search to the final Fine Phasing.


Launch day

With the final phase of preparations done .The James Webb Space Telescope was launched on an Ariane 5 rocket .The launch vehicle and launch site are part of the European Space Agency’s contribution to the mission. The Ariane 5 is one of the world’s most reliable launch vehicles and was chosen for a combination of reliability.

Launched on December 25,2021. The JWST made history and got us one step closer to uncovering the truth behind the Universe .After the launch, the telescope was  deployed on its 29-day, million-mile journey out to the second Lagrange point (L2).

The launch Segment had 3 primary components:

 1. Launch Vehicle: an Ariane 5 with the cryogenic upper stage. Provided in the single launch configuration, with a long payload fairing providing a maximum 4.57 meter static diameter and useable length of 16.19 meters.

2. Payload Adapter, comprising the Cone 3936 plus ACU 2624 lower cylinder and clamp-band, which provides the separating mechanical and electrical interface between the Webb Observatory and the Launch Vehicle.

3. Launch campaign preparation and launch campaign. The launch campaign preparation and launch campaign is the mutual responsibility of NASA, ESA, Northrop Grumman and ArianeSpace.

Mission of the JWST

The science goals for the Webb can be grouped into four themes:

1. The End of the Dark Ages: First Light and Reionization seeks to identify the first bright

objects that form the early Universe.

2. Assembly of Galaxies will determine how galaxies and dark matter evolved to the present


3. Birth of Stars and Protoplanetary Systems focuses on the birth and early development of

stars and the formation of planets.

4. Planetary Systems and the Origins of Life studies the physical and chemical properties of

solar systems, including our own.

With all this said, knowing how the JWST will change the future of space exploration on a level we can even comprehend .The only thing we can do now is wait for the first images and readings of the telescope to come and with them the start of the first wave of space exploration evolution.

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