After decades of waiting, the most powerful space observatory in human history, the James Webb Space Telescope, will be launched on December 24nd.
These marvels of engineering will help us answer fundamental questions about the universe, look back to a vast distant past, 13 billion years ago. Here are five details you need to know about this telescope.
1.Golden Mirror
The centerpiece of the telescope is a huge, basic mirror, a 6.5-meter-wide concave structure consisting of 18 small, hexagonal mirrors. Made of gold-plated beryllium, it is optimized to reflect infrared light from distant parts of the universe.
The observatory also has four scientific instruments that together serve two main purposes: to capture space objects and spectroscopy, or the scattering of light into individual wavelengths, to study the physical and chemical properties of cosmic matter.
Mirrors and instruments are protected by a five-layer solar shield that has the shape of a fan and collapses to the size of a tennis racket.
Its cover consists of a capton, a substance that is highly resistant to heat and is stable over a large temperature range, which is quite vital as the sun-exposed part of this shield will heat up to 110 degrees Celsius and the opposite side will have a temperature of -236 degrees.
The telescope also has a “spacecraft-bus”, which includes its power supply, propulsion, communications, orientation, heating and data transmission subsystems; In total, the webb is about the weight of a school bus.
2. (2.1,6 million kilometers of road)
The telescope will be placed in orbit about 1.6 million kilometers from Earth, about four times farther than the moon.
Unlike our current major space telescope, the Hubble, which orbits the Earth, James Webb will orbit the sun.
From the point of view of the sun, it will be directly behind the earth, that is, it will constantly remain on the night side of our planet. The web shield of the webb will always be between the mirror and our star.
This region of space is called the second point of Lagrange (L2) and it will take the telescope about a month to get there. It became necessary to send astronauts to repair Hubble, but in the case of James Webb, it would be impossible.
3. The Launch
Since this telescope is quite large, it is impossible to place it in the conical nose of the rocket in an operational configuration. Therefore, it should be folded like an origami. Deploying is a complex and challenging task, the most dangerous and dangerous configuration that even NASA has ever attempted.
About 30 minutes after takeoff, the communication antenna and solar panels, which will supply it with power, will be dismantled.
Then comes the unfolding of the sun shield folded like an accordion, which will begin on the sixth day, after the telescope has passed the moon. Thin membranes have a complex mechanism consisting of 400 wheels and a total of 400 m long cables.
In the second week, it will be time to open the mirror. Once it gets to the final configuration, the instruments need to be cooled and calibrated to fit the mirrors very precisely.
Six months later, the telescope will be ready to start operating.
4. Life, the universe and everything
The Webb has two major scientific missions that take up more than 50 percent of its observation time. The first is a study of the early phases of cosmic history, looking into the extremely distant past, just a few million years after the Big Bang.
Astronomers want to see how the first stars and galaxies formed and how they evolved over time.
The second major goal is to discover exoplanets, that is, planets beyond the solar system. By exploring their atmosphere, the webb will also explore the life potential of them.
The main hope of the webb is its infrared capabilities.
Unlike the ultraviolet and visible light in which Hubble operates, the long wavelengths of infrared pass more easily through the dust, giving us a better, clearer view of the cloudy early world.
In addition, the phenomenon called redshift will allow scientists to look into the more distant past. The light of distant objects expands with the expansion of the universe, in the direction of the infrared ends of the spectrum.
Closer observations of objects in the solar system, including Mars and Jupiter icy moon Europe, are also planned.
5. Decades of preparation
Astronomers began thinking about the Hubble Space Telescope back in the 1990s; Construction of the webb began in 2004.
Its launch has been delayed many times. The launch was originally planned for 2007, then in 2018… The main reason for the delays was the complexity of the telescope.
The James Webb Space Telescope is the result of a huge international collaboration. Together with NASA, it was worked on by European and Canadian space agencies.
More than 10,000 people worked on the project, and the budget exceeded $ 10 billion.
The mission is scheduled for five years, but without a doubt, it will last much longer.
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