5 Things You Need to Know About the James Webb Space Telescope

The James Webb Space Telescope, the most powerful space observatory ever built, is finally ready to launch on December 22, 2021, after decades of waiting.

An engineering marvel, James Webb will help answer fundamental questions about the universe, spying on what happened to the cosmos more than 13 billion years ago. Here for you, a list of 5 things you need to know about James Webb.

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1 – The Giant Golden Mirror

The telescope’s main piece is its huge primary mirror, a concave structure 6.5 meters in diameter, made from 18 smaller mirror segments. They are made of beryllium and covered in gold, this is done to optimize the reflection of infrared light from the most distant objects in the universe.

The space observatory also has 4 scientific instruments, which together will work for two main purposes: making images of cosmic objects, and doing spectroscopy, that is, breaking light into separate wavelengths to study the physical and chemical properties of cosmic matter.

The mirror and instruments are protected by a powerful 5-layer heat shield, which looks like a giant kite and when unfolded will be the size of a tennis court.

The heat shield membranes are composed of kapton, a material known for its high resistance to heat and also for its stability when subjected to large temperature variations, these two properties are fundamental especially when the side of the telescope facing the Sun will have a temperature of 110 degrees Celsius, while the other side of the telescope will experience a temperature of -236 degrees Celsius.

The telescope also has what is called the Space Bus, this is the part of the telescope that contains all the electrical part, the propulsion system, the communication system, which takes care of all the orientation, the heating of the instruments, it’s the part that will handle the data, and everything else connected with the functioning of James Webb.

webb orbit

2 – The 1.5 Million Kilometer Journey

The telescope will be placed in an orbit 1.5 million kilometers from Earth, which is about 4 times the distance from Earth to the Moon.

Unlike Hubble, which is a space telescope that orbits the Earth, the James Webb will orbit the Sun.

It will be directly behind the Earth from the Sun’s point of view, thus allowing it to always remain on the night side of our planet. James Webb’s heat shield will always be positioned between the mirror and the sun.

After launch, the James Webb will take about 1 month, 29 days to be precise, to reach this region in space, this point is known as the second Lagrange Point, or Lagrange Point L2. In the case of Hubble there was always the possibility of sending astronauts to repair certain problems, which happened 4 times, in the case of James Webb this will be impossible to do.

Webb unfolding sequence pillars

3 – A High Tech Origami

Because the telescope is too large to fit into the nose cone of any current rocket, in its operational configuration, it will take you into space, folded up, in the style of an origami. Unfolding the James Webb, opening the telescope, will be a complex and very challenging task, this will be the most complex opening of space equipment ever undertaken by NASA in all its years of history.

About 30 minutes after launch, the communication antenna and solar panels will begin capturing and supplying energy so that the James Webb deployment process can take place.

Then begins an incredible sequence, the heat shield will open, on the sixth day, as soon as the telescope passes the moon. Its thin membranes will be stretched using a complex system involving 400 pulleys and 400 meters of cables.

During the second week in space, James Webb’s mirrors will finally be opened. Once in their final setup, the instruments will be cooled and calibrated, and the mirrors precisely adjusted.

After six months in space, the telescope will begin its scientific operation.

Webb in a nutshell pillars

4 – Life, The Universe and Everything Else

The James Webb Space Telescope has two primary scientific missions, which together will account for more than 50% of observation time. First, explore the early stages of cosmic history, looking back to the beginning of the universe, hundreds of millions of years after the big bang.

Astronomers want to see how the first stars and galaxies formed, and how they developed over time.

The second main objective is to study exoplanets, and investigate which ones would be able to support life. James Webb will do this by studying the atmosphere of these planets.

The James Webb’s great promise lies in its infrared radiation capability.

Unlike ultraviolet light, or visible light, which Hubble detects for the most part, the longer wavelengths of infrared penetrate dust much more easily, thus allowing the early universe, hidden in clouds of dust and gas, to become clear for astronomers to see.

Infrared light also allows scientists to investigate objects further away and earlier, due to a phenomenon known as redshift, or redshift. Light from very distant objects in the universe is stretched as the universe expands, and this stretch occurs towards the infrared part of the spectrum.

But it’s not just the primordial and distant universe that James Webb will investigate, observations of much closer objects like Mars, the outer planets of the Solar System and also the moons of Jupiter, mainly Europa are planned.


5 – Manufacturing Decades

Astronomers began to debate a space telescope that should replace Hubble as early as the 1990s, and so they decided to build what was called the Next Generation Space Telescope.

Construction of the James Webb began in 2004.

And from there began one of the most dramatic stories of space exploration, its launch was originally planned to take place in 2007, then passed to 2018, this small delay of 11 years was due to all the complexity associated with the development of the space telescope. Then, in 2018, they announced that it would be released in 2020, then that date moved to July 2021, October 31, 2021, November 2021, December 18, 2021, and now it’s finally set for December 22, 2021.

The space observatory is the result of an immense international collaboration between the USA with NASA, Europe with ESA and Canada with CSA.

More than 10,000 people worked on the project, and the space telescope’s budget has already exceeded $10 billion.

The mission is planned to last at least 5 years, maybe 10!!!

What??? After 14 years of delay to the original release date, James Webb has to last at least as long as Hubble has been, so far 31 years!!!



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5 Things You Need to Know About the James Webb Space Telescope

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