The future of space telescopes: what awaits us after “James Webb” and WFIRST?

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<pre>The future of space telescopes: what awaits us after

The Hubble Space Telescope has been working for the benefit of science for over 28 years, expanding the horizons of our view of the universe and opening up new exoplanets, some of which can be inhabited. We can not verify this yet, but in the future we will have such an opportunity. Telescope “James Webb” (JWST), which should come to replace the “Hubble”, is still not going to space. The project of the more advanced NASA WFIRST telescope, which should go into space in the mid-2020s, was almost canceled, but the budget adopted on time retained the program's support. However, there are other telescopes that can surpass both James Webb and WFIRST.

The James Webb telescope in the sterilized Lyndon Johnson Space Center assembly center in Houston, USA

Recall that the launch of the long-suffering “James Webb” again moved. Now for May of 2020. Now the engineers are testing it and trying to solve the problems. And the problems, one should say frankly, reach the point of absurdity. Well, what to say, if one of the last briefings concerning the status of the assembly sounded the words “screws and nuts are pouring down from him”? The project has already invested more than 8 billion dollars. Do not be surprised if by 2020 the budget will increase not yet a couple of billions.

The wide-range infrared telescope (WFIRST). It should exceed 100 times the capabilities of the Hubble (it has a 100 times wider angle of view) and promises to deal with advanced questions in cosmology and explorations of exoplanets. His coronagraph will allow us to observe exoplanets directly and study their atmospheres. If everything goes according to plan and the launch will not be carried (in which little is believed), the telescope will go into space somewhere in the middle of 2020.

But today we are not interested in these telescopes. Today we will look further into the future and analyze the telescopes, which are planned (at least very much like) to be launched somewhere in the 2030s, that is, after the new generation of telescopes mentioned above.

HabEx

The first telescope to look out for is HabEx (Habitable Exoplanet Imaging Mission, “The mission to search for inhabited exoplanets”). This space observatory in theory will be able to conduct a direct survey of exoplanets circulating around other stars. His goals should be a wide variety of planets, starting from hot Jupiters and ending with “super-earth”. Its main task will be to search for earth-like planets and study their atmospheres.

Studies of the worlds will be carried out through the analysis of light waves, the peculiarity of which will tell about the presence of a particular biosphere in the planet

For the possibility of observing the planets of HabEx, then block the light of the stars so that you can see the less bright planets around them. There are two ways to do this.

The first one will need a coronagraph, which is by and large an artificial blocking screen installed inside the telescope and covering the rays of the star's light from it. In this case, the remaining light can be reflected from other objects located near the star and can be caught by a special detector. The presence of a mirror with a variable surface of reflection in the telescope and subsequent fine tuning will make it possible to see the planets that are located near the star.

An example of using a coronagraph installed on the VLT telescope of the European Southern Observatory can be seen below. The central star of the double star system HR 4796A in the constellation of the Centaurus is hidden, which makes it possible to see a protoplanetary disk around it.

And this, perhaps, is one of the coolest images in the history of astronomy. With the help of one of the telescopes of the Keck Observatory (Hawaii), it was possible to photograph four planets the size of Jupiter revolving around the young star HR 8799 in the constellation Pegasus. The image was created on the basis of pictures taken at different times of observation. But it looks no less impressive from this.

The second method will be to use a separate Starshade spacecraft in the form of a sunflower that will fly off tens of thousands of kilometers from the telescope and then open and block the light of the interesting star, allowing you to observe the planets around it . Starshade's design feature allows you to create a very dark shadow, providing a better view of the object of interest.

Artistic representation of the prototype Starshade – a gigantic structure designed to block the bright light of stars and subsequent observation by telescopes behind planets

Another charm of Starshade is that the device in theory can be used with almost any space observatory.

At the moment, the most effective and affordable method for detecting new exopalents is a transit search method or a method for calculating radial velocities. However, thanks to such telescopes as HabEx behind the planets it will be possible to observe directly

In addition to its main task of searching and studying exoplanets, HabEx will also deal with astrophysics, for example, observing the light of the early Universe, or studying the chemical composition of large stars before and after their collapse into supernovae.

Lynx

The next telescope is Lynx, the next-generation X-ray telescope NASA. Surprisingly the name of the device is not an acronym. It is named after a representative of the cat family – lynx (from English “lynx”). In numerous cultures, lynxes are considered to be animals possessing a supernatural ability to see the true nature of things.

X-rays are at the far end of the electromagnetic spectrum (located between ultraviolet radiation and gamma radiation) and are blocked by the earth's atmosphere. Therefore, in order to see them, you need a telescope located in space. At the moment, the flagship X-ray telescope is the NASA Space Chandra X-ray Observatory. The European Space Agency is going to launch its ATHENA X-ray telescope in 2028.

The Lynx X-ray telescope concept

Lynx is expected to work as a partner to the James Webb telescope, peering into the edges of the observed universe, revealing the secrets of the appearance of the first supermassive blacks holes and helping to make a picture of the nature of their formation and merging over time. He will also be able to observe the radiation coming from the hot gas of the early space web, collecting data on how the very first stars and galaxies were formed.

After that, Lynx is planned to be used to study the objects that Chandra, XMM Newton and other X-ray telescopes: pulsars, collapsars, supernovas, black holes and much more. Even ordinary stars can create X-ray flashes, which means they will also become objects of research.

The bulk of the matter of the universe is concentrated in clouds of gas heated to a million degrees Kelvin. And if we want to see the universe as it really is, we need to observe in the X-ray wave band.

X-ray telescopes are different from space observatories, such as the Hubble, operating in the visible wavelength range. Here it will not be possible to use an ordinary mirror, in which X-rays will be struck. Instead, to focus the rays, it is necessary to use sliding-fall mirrors, which allow the photons to enter the detector to be redirected to the detector.

The artistic representation of the Space Chandra X-ray Observatory. At the moment it is the most sensitive X-ray telescope.

Thanks to the use of a three-meter outdoor mirror, Lynx will be 50-100 times more sensitive, get a 16-times greater angle of view and will be able to capture photons 800 times faster than the Chandra.

Origins Space Telescope

The next is Origins Space Telescope or just OST. A sort of “James Webb on steroids”, which should come to replace the telescope “Spitzer”. “James Webb” has a 6.5-meter mirror, but with a 9.1-meter mirror sensitivity of the telescope Origins Space Telescope should be 30 times superior to the sensitivity of “James Webb”. It is planned that the device will operate in the infrared wavelength range and monitor the most interesting objects in the universe.

Artistic representation of the Origins Space Telescope (OST) telescope

The telescope will not only be huge, but also very cold. Aerospace Agency NASA managed to cool the telescope “Spitzer” to a temperature of 5 Kelvin. It's only 5 degrees Celsius above absolute zero and a little warmer than the temperature of the cosmic background radiation of the universe. Thanks to a special cooling system, engineers plan to cool OST to 4 Kelvin. The gap sounds small, but from a technical point of view it is a very difficult task.

Instead of cooling the device with liquid helium, as was done with the Spitzer telescope, every detail of Origins Space Telescope will need to be cooled step by step, starting with mirrors, radiators and ending with a cryocooler installed around the instruments themselves.

With the help of a huge cold infrared telescope, it is planned to study the formation of galaxies, stars and planets, as well as to search for water and greenhouse gases in exoplanet atmospheres and investigate interstellar dust.

The three projects presented above will certainly advance the development of astronomy and increase our knowledge of the universe. But the biggest and the coolest project is waiting for you below.

LUVOIR

The James Webb telescope will be a very powerful tool. But the device will work in the infrared range of waves, in order to follow the colder objects and phenomena in the universe, such as the red shift of the very first galaxies or new planetary systems. The Origins Space Telescope is designed to become a more advanced version of the James Webb telescope.

The LUVOIR telescope (Large UV Optical Infrared Surveyor) will in turn become the real heir to the Hubble. This huge device will be able to conduct observations in the visible, ultraviolet and near the infrared spectrum.

The artistic concept of the LUVOIR telescope

Two conceptual designs for this telescope are under development. According to the first, the device is planned to be equipped with a folding 8-meter mirror and put into orbit with the help of a heavy-duty rocket Falcon Heavy. According to another concept, the telescope is planned to be equipped with a mirror with a diameter of 16 meters (for comparison, the diameter of the Hubble mirror is only 2.6 meters), which is 50% larger than the largest terrestrial telescope of the same class. In the second case, it is planned to launch with the Space Launch System booster. Which version will eventually be chosen – there will be envy from the launch vehicles that will be used in 2030.

The device will receive a wide viewing angle and will be equipped with a wide variety of instruments and filters that astronomers can use to monitor anything. For example, the telescope will be equipped with a coronagraph, which was mentioned above, therefore, the device will be able to monitor the planets, “muffling” the light of their native stars. The presence of the same spectrograph will allow him to analyze the chemical composition of the atmospheres of exoplanets.

LUVOIR is designed to be an excellent universal tool, designed for great discoveries in the fields of astrophysics and planetology. Among its potential features: direct observation of exoplanets and search for biosignatures. The telescope will be able to search for planets of various classes, from hot Jupiters to “super-earths”. In addition, LUVOIR will make it possible to deduce observation of objects in the solar system to a completely different level.

Enceladus, as seen by “Hubble” (left) and how he sees LUVOIR (right)

If desired, we can look into any corner of the universe, expanding the horizons of its apparent magnitude, and also consider the much smaller objects that was not able to see “Hubble”. With the help of LUVOIR, the studies of the earliest galaxies and stars will be conducted, as well as calculations of the distribution of dark matter in the universe.

Scientists still can not fully understand what happens when the star gathers enough mass to ignite. LUVOIR will be able to turn its eyes towards the star-forming regions and consider through gas and dust the earliest moments of the birth of the stars and planets that will surround them.

Dreams and Reality

The above apparatuses fueled your enthusiasm for future astronomy? Do not rush to rejoice. The sad news is that the space telescopes presented in today's article practically do not have any chance of one day becoming our eyes, watching the distant boundaries of the cosmic horizon.

Earlier this month, the aerospace agency NASA announced that it was going to limit the appetites of the project planners to create new space telescopes and reduce development budgets to 3-5 billion dollars. Until then, engineers had not even thought about any recommendations, plans for the budget and other bureaucratic things, they simply designed new devices that could bring science to a new level.

The budget of the same telescopes HabEx, Lynx and OST according to preliminary calculations can easily cross the bar in 5 billion dollars. And the same LUVOIR will have to be forgotten altogether – the cost of its creation can easily exceed $ 20 billion.

Even though the US Congress insisted that NASA receive more funds for development, the aerospace agency itself decided to moderate as their appetites, and the appetites of their contractors. And given how much the creation of the James Webb, the advanced space telescope, and how things are going with it now, it becomes quite clear why NASA decided to take such a step.

Initially, the James Webb development project was estimated at something between $ 1.6 and $ 3.5 billion. Within the framework of this budget the device was planned to be launched in the period from 2007 to 2011. At the moment, the launch is scheduled for the earliest – for May 2020. At the same time, the development budget for the Congress estimates is already 8.8 billion dollars, and in 2 years it can increase to 10. It would be a mistake to think that only we can “cut” budget funds. But, it's not so bad. The main problem is how irresponsibly the main contractors are assembling the device.

In the last vibration test, engineers found that screws and washers were pouring from the telescope. For a minute, it's not about assembling a chest of drawers from IKEA, where in that case you could just say: “and so it goes.” It's about a telescope, for almost $ 9 billion.

Financial appetites are growing not only among the creators of the James Webb space telescope. With an initial estimate of $ 2 billion, the current estimated cost of developing the WFIRST telescope is already $ 3.9 billion.

Simple scientists hope that all these devices will sooner or later be put into orbit. Will this happen before the middle of the 2030s, as was originally planned in the programs? We need a real miracle. To this miracle, it remains to hope for researchers who believe that these devices will be able to make new important discoveries in astronomy.


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