Strongest launcher
Just recently, JWST (James. The Webb Telescope) was finally launched, and it went perfectly into space. The launch of the Weber telescope can be described as a time in human history, because it is currently the farthest human launch from the earth and the most expensive telescope in the world, reaching a price of nearly ten billion US dollars. But what is the difference with such a space telescope? Is it worth such a high price? What impact will its successful launch have on human astronomy?
JWST Program
First of all, let's talk about the background of the invention of the Webb telescope, which is the successor of the Hubble telescope. It was proposed in 1996 by a committee appointed by the American Institute of Space Telescopes, and its role is to improve the shortcomings of Hubble's observation of infrared frequency band light and promote the development of human astronomy. But this telescope has released an unknown number of pigeons, first in 2011, and then postponed to 2019, before and after more than a decade of successful launch. And what upgrades has it made over the years?
Hubble comparison
First of all, compared to the Hubble telescope, its mirror size is more than six times larger, but the weight is only half of the Hubble telescope. Although the weight reduction is a plus, its unfolding area has become a huge problem, because of the special environment of space, in order to maintain the normal operation of the equipment, scientists have designed a huge shade net.
If launched, no launch vehicle could have such a huge space for the Weber telescope, so the Weber telescope had to cut the mirror into 18 hexagons of uniform size through the special-shaped mirror scheme, and launch it into the sky by folding.
Mission location
But this leads to another risk, that is, the Weber telescope is too far away from the Earth, it is located at the Lagrange point of the Gravitational Force between the Earth and the Sun, where the Earth and the Sun cancel out the gravitational pull of the telescope.
Once the telescope's unfolding steps are wrong, looking at the operating distance of up to 1.5 million kilometers, there is almost no possibility of repair unless the spacecraft is dispatched. Naturally, the United States will not see more than ten billion US dollars at risk of drifting, so it has made certain improvements to its structure. However, some risks can only be reduced and cannot be completely solved.
Black technology
After talking about the hardware update, let's talk about one of the most important parameters of the space telescope - the observation frequency band. The Webb telescope not only inherits the visible observation band of the previous Hubble telescope, but also makes up for the shortcomings of hubble observation, and has made a huge improvement in the infrared band, and it is supported by the newly upgraded mirror.
In order to improve the sensitivity of the lens to low-frequency light, the Webb Space Telescope plated a large amount of gold on the surface of the lens, and then added beryllium, not only that. NASA's requirements for mirror accuracy have reached an outrageous point, and the mirror flatness must reach less than 10 nm, which is equivalent to the diameter of ten atoms and one ten-thousandth of an A4 piece of paper.
And after it reaches the heavens, the splicing accuracy of as many as 18 mirrors is still not bad. But this is not something that can be achieved by processing, scientists need to fine-tune through a set of extremely accurate motors, up to hundreds of steps can not be wrong. With such a complex design, what is its observation capability?
This article summarizes
In terms of observation distance, astronomers can learn about the 200 million years of the Big Bang through the Webb telescope, and the opposite Hubble can only reach about 450 million years. More importantly, the Webb telescope, which focuses on the infrared band, can find more planets than Hubble, which helps astronomers find more stars to some extent.
Another is the increase in sensitivity, because the area of the mirror increases, the Webb telescope not only has a much shorter exposure time, but also its light intake is much higher, and the space background is brighter and more stable. And the data at one time does not know what kind of surprises it will bring to human beings, and where it can promote human beings.