С каждым дополнительным сантиметром апертуры, each additional second of the observation time and each additional atom of atmospheric noise removed from the telescope's field of view can see the Universe better, deeper and more clearly.
When the Hubble telescope began to function inIn 1990, he opened a new era in astronomy - the space. There was no need to deal with the atmosphere any more, to worry about clouds or electromagnetic flicker. All that was required was to deploy the satellite to the target, stabilize it and collect photons. For 25 years, space telescopes began to cover the entire electromagnetic spectrum, which made it possible for the first time to view the Universe at each wavelength of light.
But as our knowledge increased, grew andour understanding of the unknown. The farther we look into the Universe, the deeper the past we see: a finite amount of time from the moment of the Big Bang combined with a finite speed of light provides the limit of what we can observe. Moreover, the expansion of space itself works against us, stretching the wavelength of the light of the stars as it travels through the universe to our eyes. Even the Hubble Space Telescope, which gives us the deepest, most exciting image of the universe we have ever discovered, is limited in this respect.
Hubble is an amazing telescope, but it has a number of fundamental limitations:
These galaxies are beautiful, distant and existed when the universe was only about 4% of its present age. But it is known that stars and galaxies existed even earlier.
Чтобы увидеть это, телескоп должен обладать более high sensitivity. This means a transition to longer waves and lower temperatures than the Hubble. That is why the James Webb Space Telescope is being created.
James Webb Space Telescope (JWST) is designedto overcome precisely these limitations: with a diameter of 6.5 m, a telescope allows you to collect 7 times more light than the Hubble. It opens up the possibility of high-resolution ultra-spectroscopy from 600 nm to 6 μm (4 times the wavelength that Hubble can see), to conduct observations in the mid-infrared region of the spectrum with higher sensitivity than ever before. JWST uses passive cooling to the surface temperature of Pluto and is able to actively cool the devices in the middle infrared region up to 7 K. The James Webb telescope will provide an opportunity to do science like no one has done before.
He will allow:
The level of JWST research is unlike anything in the past, and therefore the telescope was chosen as the flagship NASA mission of the 2010s.
From a technical point of view, the new telescopeJames Webb is a true work of art. The project has come a long way: there have been budget overruns, delays, and the danger of canceling the project. After the intervention of the new leadership, everything changed. The project suddenly started working like a clock, funds were allocated, mistakes, failures and problems were taken into account, and the JWST team began to fit all deadlines, schedules and budgetary frameworks. The launch of the device is scheduled for October 2018 on the rocket "Arian-5". The team not only follows the schedule, it has nine months left to take into account all unforeseen situations, so that everything will be assembled and ready for this date.
The telescope of James Webb consists of 4 main parts.
Includes all mirrors, of which the mosteighteen primary segmented gilded mirrors are effective. They will be used to collect distant starlight and focus it on tools for analysis. All of these mirrors are now ready and flawless, made right on schedule. At the end of the assembly, they will be folded into a compact structure, to be launched over a distance of more than 1 million km from the Earth to the Lagrange point L2, and then automatically turn around to form a cellular structure that will collect ultra long light for many years. This is really a beautiful thing and a successful result of the titanic efforts of many specialists.
The Webb is equipped with four scientifictools that are already 100% ready. The main camera of the telescope is a near infrared camera: from visible orange light to deep infrared. It will provide unprecedented images of the earliest stars, the youngest galaxies still in the process of formation, the young stars of the Milky Way and nearby galaxies, hundreds of new objects in the Kuiper belt. It is optimized for direct imaging of planets around other stars. This will be the main camera used by most observers.
This tool not only divides light intoseparate wavelengths, but can do it for more than 100 separate objects at the same time! This instrument will be a universal Webb spectrograph that can operate in 3 different spectroscopic modes. It was built by the European Space Agency, but many components, including detectors and a multi-shutter battery, are provided by the Space Flight Center. Goddard (NASA). This device has been tested and is ready for installation.
The device will be used for broadbandvisualization, that is, it will be used to get the most impressive images from all the Webb tools. From a scientific point of view, it will be most useful in measuring protoplanetary disks around young stars, measuring and visualizing with unprecedented accuracy Kuiper belt objects and dust heated by starlight. It will be the only instrument with cryogenic cooling to 7 K. Compared with the Spitzer space telescope, this will improve the results by 100 times.
The device will allow to produce:
This tool was created by the Canadian Space Agency. After passing through cryogenic testing, it will also be ready for integration into the instrument compartment of the telescope.
Space telescopes have not been equipped with them yet.One of the most frightening sides of every launch is the use of a completely new material. Instead of cooling the entire spacecraft actively with a one-time consumable refrigerant, the James Webb telescope uses a completely new technology — a 5-layer sunscreen that will be deployed to reflect solar radiation from the telescope. Five 25-meter sheets will be connected by titanium rods and installed after the telescope is deployed. Protection was tested in 2008 and 2009. The full-scale models that participated in the laboratory tests did everything they had to do here on Earth. This is a beautiful innovation.
In addition, it is also an incredible concept:not just block the light from the Sun and place the telescope in the shade, but do it in such a way that all heat radiates in the opposite direction of the telescope. Each of the five layers in the vacuum of space will become cold with distance from the outer layer, which will be slightly warmer than the temperature of the Earth’s surface - about 350–360 K. The temperature of the last layer should fall to 37–40 K, which is colder than at night on the surface Pluto
In addition, significant measures have been taken.precautions to protect against the adverse environment of deep space. One of the things that you should worry about here are tiny pebbles, the size of pebbles, grains of sand, dust particles and even less, flying through interplanetary space at a speed of tens or even hundreds of thousands of km / h. These micrometeorites are capable of making tiny, microscopic holes in everything they encounter: spacecraft, cosmonaut suits, telescope mirrors, and much more. If the mirrors only get dents or holes, which will slightly reduce the amount of “good light” available, then the solar shield can tear from edge to edge, making the entire layer useless. To combat this phenomenon, a brilliant idea was used.
The entire solar panel was divided into sections soThis means that if there is a small gap in one, two or even three of them, the layer will not tear further, like a crack in the windshield of the car. Partitioning will keep the whole structure intact, which is important to prevent degradation.
This is the most common component, as everyone hasspace telescopes and scientific missions. At JWST it is unique, but also completely ready. All that remains to be done by the general contractor of the Northrop Grumman project is to finish the shield, assemble the telescope and check it. The device will be ready to launch in 2 years.
If everything goes right, humanity willon the threshold of great scientific discoveries. The veil of neutral gas, which has so far obscured the review of the earliest stars and galaxies, will be removed by the infrared capabilities of Webb and its enormous luminosity. It will be the largest, most sensitive telescope with a huge range of wavelengths from 0.6 to 28 microns (the human eye can see from 0.4 to 0.7 microns) ever built. He is expected to provide a decade of observations.
According to NASA, the term of the Webb mission will be from5.5 to 10 years. It is limited by the amount of fuel that is needed to maintain the orbit, and the service life of electronics and equipment in the harsh conditions of space. The James Webb Orbital Telescope will carry fuel for the entire 10-year period, and 6 months after launch, flight support testing will be performed, which guarantees 5 years of scientific work.
The main limiting factor isamount of fuel on board. When it ends, the satellite will drift away from the L2 point of Lagrange, entering a chaotic orbit in close proximity to the Earth.
In addition to this, other troubles can occur:
The most difficult test that awaits the James Webb telescope - launch and launch into a given orbit. It is these situations that have been tested and successfully passed.
If the James Webb telescope will work inin normal mode, there will be enough fuel to ensure its operation from 2018 to 2028. In addition, there is the potential for refueling, which could extend the life of the telescope by another decade. Just as Hubble has been exploited for 25 years, JWST could provide a generation of revolutionary science. In October 2018, the launch vehicle "Arian-5" will bring into orbit the future of astronomy, which, after more than 10 years of hard work, is already ready to begin to bear fruit. The future of space telescopes is almost here.
