There are three objects in the Earth's orbit that even people far from astronomy and astronautics know about: the Moon, the International Space Station and the Hubble Space Telescope. The latter is eight years older than the ISS and also found the Mir Orbital Station. Many consider it just a big camera in space. reality Little more difficult, not in vain, because people working with this unique apparatus respectfully call it a celestial observatory.

A lot of pictures!

The history of the construction of Hubble is a constant overcoming of difficulties, the struggle for funding and the search for solutions to unforeseen situations. The role of Hubble in science is priceless. It is impossible to compile a complete list of discoveries in astronomy and related areas, made thanks to the images of the telescope, so many works refer to the information received by him. Nevertheless, official statistics speak of almost 15,000 publications.

Story

The idea of ​​placing a telescope in orbit arose almost a hundred years ago. The scientific rationale for the importance of building such a telescope in the form of an article was published by astrophysicist Lyman Spitzer in 1946. In 1965, he was made head of the committee of the Academy of Sciences, which determined the tasks of such a project.

In the sixties, several successful launches and simpler devices were delivered to orbit, and in the 68th NASA gave the green light to Hubble's forerunner - the LST apparatus, the Large Space Telescope, with a larger mirror diameter - 3 meters versus Hubble's 2.4 - and an ambitious the task of launching it already in the 72nd year, with the help of the space shuttle that was then under development. But the estimated project estimate turned out to be too expensive, there were difficulties with money, and in the 74th funding was completely canceled. The active lobbying of the project by astronomers, the involvement of the European Space Agency and the simplification of the characteristics to approximately the Hubble ones made it possible in the 78th to receive funding from Congress in the amount of ridiculous total costs of 36 million dollars, which today is equal to about 137 million.

At the same time, the future telescope was named after Edwin Hubble, an astronomer and cosmologist who confirmed the existence of other galaxies, created the theory of the expansion of the Universe and gave his name not only to the telescope, but also to the scientific law and magnitude.

The telescope was developed by several companies responsible for different elements, of which the most complex: the optical system, which was handled by Perkin-Elmer, and the spacecraft, which was created by Lockheed. The budget has already grown to $400 million.

Lockheed delayed the creation of the apparatus for three months and exceeded its budget by 30%. If you look at the history of construction of devices similar in complexity, then this is a normal situation. At Perkin-Elmer, things were much worse. The company polished the mirror using innovative technology until the end of 1981, grossly over budget and damaging relations with NASA. Interestingly, the mirror blank was made by the Corning company, which today produces Gorilla Glass, which is actively used in phones. Incidentally, Kodak has been contracted to make a spare mirror using traditional polishing methods if there is a problem polishing the primary mirror. Delays in the creation of the remaining components slowed down the process so much that a quote from NASA's characterization of the work schedules that was "indefinite and changing daily."

The launch became possible only by the year 86, but due to the Challenger disaster, shuttle launches were suspended for the duration of the improvements.

Hubble was stored piecemeal in special nitrogen-purged chambers at a cost of six million dollars a month.

As a result, on April 24, 1990, the Discovery shuttle launched with a telescope into orbit. By this point, $2.5 billion had been spent on Hubble. Total costs today are approaching ten billion.

Since the launch, there have been several dramatic events involving Hubble, but the main thing happened at the very beginning.

When, after launching into orbit, the telescope began its work, it turned out that its sharpness was an order of magnitude lower than the calculated one. Instead of a tenth of an arc second, a whole second was obtained. After several checks, it turned out that the telescope mirror was too flat at the edges: by as much as two micrometers it did not match the calculated one. Aberration due to this literally microscopic defect made most of the planned studies impossible.

A commission was assembled, whose members found the reason: an incredibly accurately calculated mirror was incorrectly polished. Moreover, even before the launch, the same deviations were shown by a pair of null correctors used in the tests - devices that were responsible for the desired surface curvature here. But then they did not trust these indications, relying on the indications of the main zero-corrector, which showed the correct results and according to which polishing was carried out. And one of the lenses of which, as it turned out, was incorrectly installed.

Human factor.

Installing a new mirror directly in orbit was technically impossible, and lowering the telescope and then bringing it out again was too expensive. The solution was an elegant one.

Yes, the mirror was made wrong. But it was done incorrectly with very high precision. The distortion was known, and it only needed to be compensated for, for which a special COSTAR correction system was developed. It was decided to install it as part of the first expedition to maintain the telescope. Such an expedition is a complex ten-day operation with astronauts going into outer space. A more futuristic work cannot be imagined, and this is just maintenance. In total, there were four expeditions during the operation of the telescope, with two departures as part of the third.

On December 2, 1993, the Space Shuttle Endeavor, for which it was the fifth flight, delivered the astronauts to the telescope. They installed Kostar and replaced the camera.

Costar corrected the spherical aberration of the mirror, playing the role of the most expensive glasses in history. The optical correction system performed its task until 2009, when the need for it disappeared due to the use of its own corrective optics in all new devices. She gave way to a precious place in the telescope to the spectrograph and took pride of place in the National Museum of Aeronautics and Astronautics, after being dismantled as part of the fourth Hubble maintenance expedition in 2009.

Control

The telescope is controlled and monitored 24/7 in real time from a control center in Greenbelt, Maryland. The tasks of the center are divided into two types: technical (maintenance, management and condition monitoring) and scientific (selection of objects, preparation of tasks and direct data collection). Every week, Hubble receives more than 100,000 different commands from the Earth: these are orbit-correcting instructions, and tasks for shooting space objects.

In the MCC, the day is divided into three shifts, each of which is assigned a separate team of three to five people. During expeditions to the telescope itself, the staff of workers increases to several dozen.

By the way, there is a separate site developed by Chris Peet where you can track the position of the celestial observatory. There is also data on other artificial orbital objects:
www.heavens-above.com

Hubble is a busy telescope, but even its busy schedule can help absolutely any, even non-professional, astronomer. Every year, it receives a thousand requests for booking time from astronomers from different countries. About 20% of applications are approved by an expert committee and, according to NASA, plus or minus 20,000 observations are made annually thanks to international requests. All these applications are docked, programmed and sent to Hubble from the same center in Maryland.

Optics

Current set of tools:

NICMOS
Near Infrared Camera and Multi-Object Spectrometer
Near infrared camera and multi-object spectrometer

ACS
Advanced Camera for Surveys
Advanced overview camera

WFC3
Wide Field Camera 3
Wide Camera 3

COS
Cosmic Origins Spectrograph
Ultraviolet spectrograph

STIS
Space Telescope Imaging Spectrograph
Space telescope recording spectrograph

FGS
Fine Guidance Sensor
Guidance system

Hubble's main optics are based on the Ritchey-Chrétien system. It consists of a round, hyperbolically curved mirror 2.4 m in diameter with a hole in the center. This mirror reflects onto a secondary mirror, also of a hyperbolic shape, which reflects a digitizable beam into the central hole of the primary. All sorts of filters are used to filter out unnecessary parts of the spectrum and highlight the desired ranges.

In such telescopes, it is the system of mirrors that is used, and not lenses, as in cameras. There are many reasons for this: temperature differences, polishing tolerances, overall dimensions, and the absence of beam loss within the lens itself.

The main optics on Hubble have not changed since the beginning. And the set of various tools that use it was completely changed over several service expeditions. Hubble was updated instrumentation, and during its existence, thirteen different instruments worked there. Today he carries six, one of which is in hibernation.

The wide-angle and planetary cameras of the first and second generations were responsible for photographs in the optical range, and the Wide-angle camera of the third now.

The potential of the first WFPC was never realized due to problems with the mirror. And the expedition of 93, having installed Kostar, at the same time replaced it with the second version.

The WFPC2 camera had four square sensors, the images from which formed a large square. Almost. One matrix - just the same "planetary" - received an image with a higher magnification, and when the scale is restored, this part of the image captures less than a sixteenth of the total square instead of a quarter, but in higher resolution. The remaining three matrices were responsible for the "wide angle". This is why full camera shots look like a square that has had 3 blocks eaten from one corner, and not due to problems with uploading files or other problems.

WFPC2 was replaced by WFC3 in 2009. The difference between them is well illustrated by the re-shot Pillars of Creation, which will be discussed later.

In addition to the optical and near-infrared range of the wide-angle camera, Hubble sees:

• using the STIS spectrograph in the near and far ultraviolet, as well as from visible to near infrared;
• in the same place using one of the ACS channels, the other channels of which cover a huge frequency range from infrared to ultraviolet;
• weak point sources in the ultraviolet range by the COS spectrograph.

Snapshots

Hubble images are not quite photographs in the usual sense. A lot of information is not available in the optical range. Many space objects actively radiate in other ranges. Hubble is equipped with a variety of devices with a variety of filters that allow you to capture data that astronomers later process and can reduce to a visual image. The richness of colors is provided by different ranges of radiation from stars and particles ionized by them, as well as their reflected light.

There are a lot of photos, I will tell you only about a few of the most exciting ones. All photos have their own ID, which can be easily located on the Hubble website spacetelescope.org or directly in Google. Many of the pictures are in high resolution on the site, but here I leave the screensize versions.

Hubble took his most famous shot on April 1, 1995, without being distracted from smart work on April Fool's Day. These are the Pillars of Creation, so named because stars are formed from these accumulations of gas, and because they resemble in shape. The picture shows a small piece of the central part of the Eagle Nebula. This nebula is interesting in that the large stars in its center partly scattered it, and even just from the side of the Earth. Such luck allows you to look into the very center of the nebula and, for example, take the famous expressive picture.

Other telescopes also shot this region in different ranges, but in the optical Pillars come out most expressively: ionized by the very stars that scattered part of the nebula, the gas glows in blue, green and red colors, creating beautiful overflows.

In 2014, the Pillars were re-shot with updated Hubble equipment: the first version was filmed by the WFPC2 camera, and the second by WFC3.

A rose made from galaxies

ID: heic1107a

The object Arp 273 is a beautiful example of communication between galaxies that are close to each other. The asymmetric shape of the upper is a consequence of the so-called tidal interactions with the lower. Together they form a grandiose flower, presented to humanity in 2011.

Magic Galaxy Sombrero

ID: opo0328a

Messier 104 is a majestic galaxy that seems to have been invented and painted in Hollywood. But no, the beautiful one hundred and fourth is located on the southern outskirts of the constellation Virgo. And it is so bright that it is visible even in home telescopes. This beauty posed for Hubble in 2004.

New Infrared View of the Horsehead Nebula - Hubble 23rd Anniversary Image

ID: heic1307a

In 2013, Hubble re-imaged Barnard 33 in infrared. And the gloomy Horsehead Nebula in the constellation of Orion, almost opaque and black in the visible range, appeared in a new light. That is, range.

Before that, Hubble had already photographed it in 2001:

Hubble captures star-forming region S106

ID: heic1118a

S106 is a star-forming region in the constellation Cygnus. The beautiful structure is due to the ejecta of a young star, which is shrouded in donut-shaped dust in the center. This dust curtain has gaps at the top and bottom, through which the material of the star breaks out more actively, forming a shape resembling a well-known optical illusion. The picture was taken at the end of 2011.

Cassiopeia A: colorful consequences of the death of a star

ID: heic0609a

You have probably heard about supernova explosions. And this picture clearly shows one of the scenarios for the further fate of such objects.

In the photo of 2006 - the consequences of the explosion of the star Cassiopeia A, which happened right in our galaxy. The wave of matter spreading from the epicenter is perfectly visible, with a complex and detailed structure.

Hubble Arp 142 image

ID: heic1311a

And again, a picture showing the consequences of the interaction of two galaxies that were close to one another during their Universe journey.

NGC 2936 and 2937 collided and impacted each other. This is already an interesting event in itself, but in this case, another aspect was added: the current shape of galaxies resembles a penguin with an egg, which works as a big plus for the popularity of these galaxies.

In a cute picture from 2013, you can see traces of the collision: for example, the penguin's eye is formed, for the most part, by bodies from the egg galaxy.

Knowing the age of both galaxies, we can finally answer what happened before: an egg or a penguin.

A butterfly emerging from the remnants of a star in planetary nebula NGC 6302

ID: heic0910h

Sometimes hot gas streams up to 20 thousand degrees, flying at a speed of almost a million km / h, look like the wings of a fragile butterfly, you just need to find the right angle. Hubble did not have to look, the nebula NGC 6302 - it is also called the Butterfly or Beetle Nebula - itself turned to us in a suitable direction.

These wings are created by a dying star in our galaxy in the constellation Scopio. The shape of the wings of the streams of gas is again due to the ring of dust around the star. The same dust closes the star itself from us. It is possible that the ring was formed by the loss of matter from the star along the equator at a relatively low speed, while the wings were formed by a faster loss from the poles.

The photo was taken in 2009.

deep field

There are several Hubble images that have Deep Field in their title. These are frames with a huge multi-day exposure time, showing a small piece of the starry sky. To remove them, I had to very carefully choose a site suitable for such an exposure. It should not have been blocked by the Earth and the Moon, there should not have been bright objects nearby, and so on. As a result, Deep Fields have become very useful frames for astronomers, which can be used to study the processes of formation of the universe.

The most recent such frame - the Hubble Extreme Deep Field of 2012 - is rather boring to the layman's eye - this is an unprecedented shooting with an exposure of two million seconds (~ 23 days), showing 5.5 thousand galaxies, the dimmest of which have a brightness of ten billion less than the sensitivity of human vision.

Ever since the dawn of astronomy, since the time of Galileo, astronomers have had one common goal: to see more, to see further, to see deeper. And the Hubble Space Telescope, launched in 1990, is a huge step in that direction. The telescope is in Earth orbit above the atmosphere, which could distort and block the radiation coming from space objects. Thanks to its absence, astronomers get pictures of the highest quality with the help of Hubble. It is almost impossible to overestimate the role that the telescope played for the development of astronomy - Hubble is one of the most successful and long-term projects of the NASA space agency. He sent hundreds of thousands of photographs to Earth, shedding light on many secrets of astronomy. He helped determine the age of the universe, identify quasars, prove that massive black holes are at the center of galaxies, and even set up experiments to detect dark matter.

The discoveries changed the view of astronomers on the Universe. The ability to see in great detail helped turn some astronomical hypotheses into facts. Many theories have been discarded in order to go in one right direction. Among the achievements of Hubble, one of the main ones is the determination of the age of the Universe, which scientists today estimate at 13-14 billion years. This is undoubtedly more accurate than the previous data of 10–20 billion years. Hubble also played a key role in the discovery of dark energy, the mysterious force that causes the universe to expand at an ever-increasing rate. Thanks to Hubble, astronomers were able to see galaxies at all stages of their development, starting from the formation that took place in the young Universe, which helped scientists understand how they were born. With the help of the telescope, protoplanetary disks, accumulations of gas and dust around young stars were found, around which soon (by astronomical standards, of course) new planetary systems will appear. He was able to find the sources of gamma-ray explosions - strange, unbelievably powerful bursts of energy - in distant galaxies during the collapse of supermassive stars. And this is only part of the discoveries of a unique astronomical instrument, but already proving that the $2.5 billion spent on creation, launch into orbit and maintenance is the most profitable investment on the scale of all mankind.

Hubble Space Orbital Telescope

Hubble has amazing performance. The entire astronomical community enjoys his ability to see the depths of the universe. Each astronomer can send a request for a certain time of using his services, and a group of specialists decides if this is possible. After the observation is made, as a rule, a year passes before the astronomical community receives the results of the research. Since the data obtained using the telescope is available to everyone, any astronomer can conduct his research, coordinating the data with observatories around the world. Such a policy makes research open, and therefore more effective. However, the unique capabilities of the telescope also mean the highest level of demand for it - astronomers around the world are fighting for the right to use the Hubble services in their spare time from the main missions. Every year more than a thousand applications are received, among which the best are selected according to experts, but according to statistics, only 200 are satisfied - only a fifth of the total number of applicants conduct their research using Hubble.

Why was it necessary to bring the telescope into near-Earth space, and why is the device in such high demand among astronomers? The fact is that the Hubble telescope was able to solve two problems of ground-based telescopes at once. First, the smearing of the earth's atmosphere signal limits the capabilities of ground-based telescopes, regardless of their technical sophistication. Thanks to atmospheric blurring, we see the stars twinkle when we look at the sky. Secondly, the atmosphere absorbs radiation with a certain wavelength, most of all ultraviolet, x-ray and gamma radiation. And this is a serious problem, since the study of space objects is the more effective, the larger the energy range is taken.
And it is precisely in order to avoid the negative influence of the atmosphere on the quality of the images obtained that the telescope is located above it, at a distance of 569 kilometers above the surface. At the same time, the telescope makes one revolution around the Earth in 97 minutes, moving at a speed of 8 kilometers per second.

Optical system of the Hubble telescope

The Hubble telescope is a Ritchey-Chrétien, or improved version of the Cassegrain system, in which light initially hits the primary mirror, is reflected, and enters the secondary mirror, which focuses the light and directs it to the telescope's scientific instrument system through a small hole in the primary mirror. Often people mistakenly believe that a telescope magnifies an image. In fact, it only collects the maximum amount of light from the object. Accordingly, the larger the main mirror, the more light it will collect and the clearer the image will be. The second mirror only focuses the radiation. Hubble's primary mirror is 2.4 meters in diameter. It seems small, considering that the diameter of the mirrors of ground-based telescopes reach 10 meters or more, but the absence of an atmosphere, nevertheless, is a huge advantage of the comic version.
To observe space objects, the telescope has a number of scientific instruments, working together or separately. Each of them is unique in its own way.

Advanced Camera for Surveys (ACS). The newest instrument for observations in the visible range, designed for studies of the early Universe, and installed in 2002. This camera helped to map the distribution of black matter, detect the most distant objects and study the evolution of galaxy clusters.

Near infrared camera and multi-object spectrometer (Near Infrared Camera and Multi-Object Spectrometer - NICMOS). An infrared sensor detects heat when objects are obscured by interstellar dust or gas, such as in regions of active star formation.

Near infrared camera and multi-object spectrometer (Space Telescope Imaging Spectrograph - STIS). Acts like a prism, spreading light. From the resulting spectrum, one can obtain information about the temperature, chemical composition, density, and motion of the objects under study. STIS ceased operation on August 3, 2004 due to technical problems, but will be repaired in 2008 during a scheduled maintenance of the telescope.

Wide Field and Planetary Camera 2 (WFPC2). A universal tool with which most of the photographs known to everyone were taken. Thanks to 48 filters, it allows you to see objects in a fairly wide range of wavelengths.

Fine Guidance Sensors (FGS). They are not only responsible for the control and orientation of the telescope in space - they orient the telescope in relation to the stars and do not allow to go astray, but also make precision measurements of the distances between the stars and fixes the relative movement.
Like many spacecraft in Earth orbit, the Hubble telescope is powered by solar radiation, which is detected by two twelve-meter solar panels and accumulated for uninterrupted operation during passage along the shadow side of the Earth. The design of the guidance system for the desired target - an object in the Universe - is also very interesting - after all, successfully photographing a distant galaxy or quasar at a speed of 8 kilometers per second is a very difficult task. The telescope orientation system includes the following components: the already mentioned fine pointing sensors, which mark the position of the device relative to the two "leading" stars; position sensors relative to the Sun - not only auxiliary tools for telescope orientation, but also the necessary tools to determine the need to close / open the aperture door, which prevents the equipment from “burning out” when focused sunlight hits it; magnetic sensors that orient the spacecraft relative to the Earth's magnetic field; a system of gyroscopes that track the movement of the telescope; and an electro-optical detector that monitors the position of the telescope relative to the selected star. All this provides not only the ability to control the telescope, "aiming" at the desired space object, but also prevents the breakdown of valuable equipment that cannot be promptly replaced with a workable one.

However, Hubble's work would be meaningless without the possibility of transmitting the data obtained for study in terrestrial laboratories. And to solve this problem, four antennas were installed on the Hubble, which exchange information with the flight control center (Flight Operations Team) of the Goddard Space Flight Center in Greenbelt (Greenbelt). Satellites in earth orbit are used to communicate with the telescope and set coordinates, they are also responsible for relaying data. Hubble has two computers and several less complex subsystems. One of the computers controls the navigation of the telescope, all other systems are responsible for the operation of the instruments and communication with satellites.

Scheme of information transfer from orbit to earth

Data from the ground-based research team goes to the Goddard Space Flight Center, then to the Space Telescope Science Institute, where a team of specialists process the data and record it on magneto-optical media. Every week, the telescope sends information to Earth that can fill more than twenty DVDs, and access to this huge array of valuable information is open to everyone. Most of the data is stored in the FITS digital format, which is very convenient for analysis, but extremely unsuitable for publication in the media. That is why the most interesting images for the general public are published in more common image formats - TIFF and JPEG. Thus, the Hubble telescope has become not only a unique scientific instrument, but also one of the few opportunities to look at the beauties of the Cosmos for anyone - a professional, an amateur, and even a person unfamiliar with astronomy. To some regret, we have to say that the access of an amateur astronomer to the telescope is closed today due to a decrease in funding for the project.

Hubble orbiting telescope

The past of the Hubble telescope is no less interesting than its present. For the first time, the idea of ​​​​creating such an installation arose back in 1923 from Hermann Oberth, the founder of German rocket technology. It was he who first spoke about the possibility of delivering a telescope to near-Earth orbit using a rocket, although even the rockets themselves did not exist then. This idea was developed in 1946 in his publications on the need to create a space observatory by the American astrophysicist Lyman Spitzer. He predicted the possibility of obtaining unique photographs that are simply impossible to take on the ground. Over the next fifty years, the astrophysicist actively promoted this idea until the beginning of its actual application.

Spitzer has been a leader in the development of several orbital observatory projects, including the Copernicus satellite and the Orbiting Astronomical Observatory. Thanks to him, the project Large Space Telescope (Large Space Telescope) was approved in 1969, unfortunately, due to lack of funding, the dimensions and equipment of the telescope were somewhat reduced, including the size of the mirrors and the number of instruments.

In 1974, it was proposed to make interchangeable instruments with a resolution of 0.1 arcseconds and a working wavelength range from ultraviolet to visible and infrared. The shuttle was supposed to take the telescope into orbit and return it to Earth for maintenance and repair, which was also possible in space.

In 1975, NASA, together with the European Space Agency (ESA), began work on the Hubble telescope. In 1977, funding for the telescope was approved by Congress.

After this decision, a list of scientific instruments of the telescope began to be drawn up, five winners of the competition for the creation of equipment were selected. There was a lot of work ahead. They decided to name the telescope in honor of the astronomer who showed that the small "patches" visible through the telescope are distant galaxies - and proved that the Universe is expanding.

After all sorts of delays, the launch was scheduled for October 1986, but on January 28, 1986, the Space Shuttle Challenger exploded a minute after launch. Checking the shuttles lasted more than two years, which means that the launch of the Hubble telescope into orbit was postponed for four years. During this time, the telescope improved, on April 24, 1990, a unique apparatus rose into its orbit.

Shuttle launch with the Hubble telescope on board

In December 1993, the shuttle Endeavor, with a crew of seven, was flown into orbit to perform maintenance on the telescope. Two cameras were replaced, as well as solar panels. In 1994, the first photographs were taken from the telescope, the quality of which shocked astronomers. Hubble has fully justified itself.

Maintenance, upgrading and replacement of cameras, solar panels, inspection of heat shielding, and maintenance were carried out three more times: in 1997, 1999 and 2002.

Modernization of the Hubble telescope, 2002

The next flight was supposed to take place in 2006, but on February 1, 2003, due to problems with the skin, the Columbia space shuttle burned up in the atmosphere during the return. As a result, there was a need for additional studies on the possibility of further use of the Shuttle, which ended only on October 31, 2006. This is what led to the postponement of the next scheduled maintenance of the telescope to September 2008.
Today the telescope is operating normally, transmitting 120 GB of information weekly. A successor to Hubble, the Webb Space Telescope, is also being developed, which will explore high-redshift objects in the early universe. It will be at an altitude of 1.5 million kilometers, the launch is scheduled for 2013.

Of course, Hubble is not eternal. The next repair is scheduled for 2008, but still the telescope gradually wears out and becomes inoperable. This will happen around 2013. When this happens, the telescope will remain in orbit until it degrades. Then, in a spiral, Hubble will begin to fall to the Earth, and either follow the Mir station, or be safely delivered to Earth and become a museum exhibit with a unique history. But still, the legacy of the Hubble telescope: its discoveries, its example of almost flawless work and photographs, known to everyone, will remain. You can be sure that his achievements will help unravel the mysteries of the universe for a long time to come, as a triumph of the amazingly rich life of the Hubble telescope.

At the end of September 2008 at the telescope. Hubble failed the unit responsible for transmitting information to Earth. The telescope repair mission was rescheduled to February 2009.

Technical characteristics of the telescope. Hubble:

Launch: April 24, 1990 12:33 UT
Dimensions: 13.1 x 4.3 m
Weight: 11 110 kg
Optical design: Ritchie-Chretien
Vignetting: 14%
Field of view: 18" (for scientific purposes), 28" (for guiding)
Angular Resolution: 0.1" at 632.8 nm
Spectral range: 115 nm - 1 mm
Stabilization accuracy: 0.007" in 24 hours
Estimated spacecraft orbit: altitude - 693 km, inclination - 28.5°
Rotation period around Zesli: between 96 and 97 minutes
Planned operating time: 20 years (with maintenance)
Telescope and spacecraft cost: $1.5 billion (in 1989 dollars)
Main mirror: Diameter 2400 mm; Radius of curvature 11,040 mm; Square of eccentricity 1.0022985
Secondary mirror: Diameter 310 mm; Radius of curvature 1.358 mm; Square of eccentricity 1.49686
Distances: Mirror centers 4906.071 mm; From secondary mirror to focus 6406.200 mm

Image copyright BBC World Service Image caption Hubble was launched into orbit by the shuttle Discovery on April 24, 1990.

This week marks the 25th anniversary of the launch of the Hubble Space Telescope. The Silver Anniversary was marked by yet another image showing young stars shining against a thick cloud of gas and dust.

This star cluster - Westerlund 2 - is located 20 thousand light-years from Earth in the constellation Carina.

Image copyright BBC World Service Image caption Shortly after the launch of the telescope, a defect in its main mirror was revealed, which made all the pictures fuzzy.

NASA engineers believe that the orbiting telescope will last at least another five years.

"The biggest optimist could not have predicted in 1990 to what extent Hubble would rewrite all of our astrophysics and planetary science textbooks," says NASA administrator Charlie Bolden.

Shortly after the launch of the telescope, a defect in its main mirror was revealed, which made all the pictures fuzzy.

In 1993, astronauts managed to correct this defect by installing a specially designed corrective device.

Image copyright BBC World Service Image caption Many Hubble images, such as the Eagle Nebula, have become a scientific sensation.

Four more maintenance visits later, the telescope is in excellent condition and technically capable of much more than just after launch.

In the past, Hubble has suffered from gradual wear and tear on all of its six gyroscopes that are used in the orientation system.

However, after their replacement, only one failed in March 2014. Over the past years, thanks to the replacement of obsolete electronic components and the installation of new cameras, the telescope began to work noticeably better.

Image copyright BBC World Service Image caption This image of Jupiter and its moon Ganymede is dramatic

It is difficult to overestimate the contribution of this orbiting telescope to science.

At the time of its launch, astronomers knew nothing about the age of the universe - estimates ranged from 10 to 20 billion years.

A telescope study of pulsars has narrowed this down, and current thinking is that 13.8 billion years have passed since the Big Bang.

Image copyright BBC World Service Image caption Hubble helped determine the age of the universe, which is currently thought to be 13.8 billion years

Hubble was instrumental in discovering the rate at which the universe is expanding and also provided decisive evidence for the existence of supermassive black holes at the centers of galaxies.

The strength of the space telescope compared to the new generation of terrestrial telescopes remains its unique ability to penetrate into the deep past of the universe, observing objects that formed very early in its history.

Image copyright BBC World Service Image caption The Crab Nebula is 6,500 light-years away and is the remnants of a supernova explosion.

Among the greatest achievements of the telescope, undoubtedly, should be mentioned the observations of the "deep field", when for many days it recorded the light coming to us from the dark part of the sky and revealed the presence of thousands of extremely distant and very faintly luminous galaxies.

At present, the telescope is engaged in such observations most of the time as part of the Frontier Fields program. Hubble looks at six huge clusters of ancient galaxies.

Image copyright NASA Image caption Each of the glowing objects in this image is a distant galaxy.

Using the effect of gravitational lensing, Hubble is able to look into the even more distant past of the universe.

"Gravity, by distorting the light coming from distant galaxies, allows us to look beyond these clusters," says Jennifer Lotz, a participant in the program.

"Hubble" is currently able to "see" objects, the light from which is 10-50 times weaker than previously observed.

The aim of these studies is to observe the earliest stages in the formation of the first generation of stars and galaxies that are only a few hundred million years distant from the Big Bang.

Image copyright BBC World Service Image caption "Expanding Universe": photographs of the Hubble telescope, Taschen publishing house

And that's what Hubble's successor, the much larger and more advanced James Webb Space Telescope, will do on another level.

Its launch is scheduled for 2018. It was designed and built specifically for this task. Taking pictures that take days and weeks for the Hubble Space Telescope will only take hours.

The Hubble Telescope, named after the American astronomer Edwin Hubble (1889-1953), was launched into low Earth orbit on April 24, 1990. During his work, more than a million images of stars, planets, galaxies, nebulae and other space objects have been obtained.

The Earth's atmosphere is opaque, so if Hubble were located on the surface of our planet, it would see ten times worse.

Immediately after the launch of the telescope, it turned out that its main mirror had a defect, due to which the sharpness and resolution of the obtained images were much worse than expected. Throughout the history of the telescope, there have been five expeditions to service it. The main task of the first flight to Hubble was, of course, to eliminate the mirror defect by installing corrective optics. It was one of the most difficult expeditions in the history of our exploration of extraterrestrial space. Astronauts have completed five long spacewalks; several cameras, solar panels, guidance systems were replaced ... At the end of the work, the orbit was adjusted, because due to friction against the air when moving in the upper atmosphere, a loss of altitude occurred. The mission was completed successfully and the pictures taken after the mission were very good. In further expeditions, scheduled maintenance work and replacement of equipment with more modern ones were carried out. For a long time, the fifth flight to Hubble was in doubt.

After the disaster of the spacecraft Columbia in March 2003, maintenance work on the telescope was temporarily suspended. NASA decided that every space shuttle should be able to get to the ISS in case of technical problems.

However, the need for maintenance work is clearly overdue. NASA was faced with a serious question: take the risk or leave it as it is? The fifth flight to Hubble took place against all odds in the spring of 2009, after NASA had a new administrator. It was decided that this Hubble expedition would be the last.

How do you get bright and colorful images from Hubble?

Hubble takes pictures of space objects in various ranges from infrared to ultraviolet, the output is black and white photographs of very good quality and resolution. Where do these bright color images come from, which first appear on the NASA website, and then roam all over the Internet? The answer is rather banal: Photoshop. The photo editing process is complex and time-consuming, don't be fooled by the two-minute length of the video. Here's what it looks like:

The most famous images from Hubble:

Pillars of Creation

The Pillars of Creation or Elephant Trunks are a collection of stardust and gas in the Eagle Nebula (7,000 light-years from Earth).

The Andromeda Galaxy, 2.5 million light-years from Earth:

Galaxy M83, 15 million light years from Earth:

The Crab Nebula is the result of a supernova explosion in 1054 AD; in the center of the nebula is a neutron star (the mass is of the same order as that of our Sun, the size is like a small city).

Galaxy NGC 5194, 23 million light years from Earth:

Bottom left - a supernova that erupted in 1994 on the outskirts of a spiral galaxy

The Sombrero Galaxy, 30 million light years from Earth:

The Omega Nebula in the constellation Sagittarius, 5,000 light-years from Earth:

The best pictures from the Hubble telescope. You can put it in full screen and enjoy:

The Hubble Space Telescope (named after Edwin Hubble) is an autonomous observatory in Earth orbit, a joint project between NASA and the European Space Agency. In space, telescopes are placed in order to register electromagnetic radiation in the ranges that the earth's atmosphere does not let through. Hubble has worked for almost 15 years (since 1990) and continues to work (although the main mission is completed and Hubble's colleagues Spitzer and Kepler, launched in 2003 and 2009, respectively, continue it). A colossal project in its significance, with the help of which a myriad of theories were tested and a huge number of discoveries were made. Maps of Pluto and Eris, high-quality images of comets, confirmation of the hypothesis of the isotropy of the Universe, the discovery of a new satellite of Neptune - Hubble has brought so much data that their study continues and continues.

At the end of 2018, the OSIRIS-Rex space probe entered the orbit of the asteroid Bennu and revealed interesting features about its structure. It would seem that with such a proximity of the device, all new discoveries should be made only with the help of its onboard equipment, but no. Researchers