Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

The Most Rigid Telescope

18.06.2002


The scientists from NPO Astrofizika, have designed a terrestrial telescope, which has no match all over the world. Fundamentally new technical solutions ensure that a unique telescope with the mirror of 25 meters in diameter is able to investigate previously invisible celestial objects of up to the 29-th magnitude.



What makes astronomers design the telescopes with the larger and larger mirrors? Certainly, astronomers are driven by the capacity of a telescope to provide more information about the Universe. The larger the mirror is, the larger amount of light from one source the telescope can catch, thus enabling the scientists to descry and investigate remoter or smaller objects. At present there are telescopes available with the main mirror of 8 and even 10 meters in diameter. For instance, in Russia the largest is the Zelenchuk telescope with a mirror of 6 meters in diameter. The Americans have installed the telescope in Hawaii and the Europeans - in Chile, the mirrors being 10 meters in diameter, but the astronomers have almost exhausted capacities of these telescopes. Now the astronomers are eager to use a telescope with a larger mirror - as big as of 100 meters in diameter.

However, large mirrors entail significant, sometimes insoluble problems. Such enormous mirrors are difficult to manufacture, install and maintain. Even minor deviations from the standard lead to tremendous distortions and consequently errors. That is why, before starting the development of the super-telescope, the Moscow astrophysicists have analysed the sources of possible errors (they have calculated the budget of errors, as they put it) and have come to the conclusion that it is unreasonable to manufacture a terrestrial telescope with the mirror of more than 25 meters in diameter, as the inevitable distortions will not allow astronomers to obtain more information.


However, a huge mirror is difficult to manufacture. It should not be too heavy, it should be strongly fastened and reliably protected from vibrations - a gust or an earthquake tremor, or even the auxiliary devices operation can loosen the dish which is as big as a playground. And finally, the mirror should be easy to operate, i.e. to turn it in the required direction.

To solve these and multiple other problems, the scientists applied several technical ideas at a time, having had previously patented them. First, they have decided to make a composite mirror, instead of a monolithic one - it will consist of individual controllable mirrors of 1-meter in diameter, the shape of mirrors being that of regular hexagons. The 10-meter mirror of the existing Keck-telescope (USA) was designed in the same way. On top of that, at each moment the mirror will automatically take the shape of the surface, which ensures the high image quality (i.e., adaptive mirror). The Russian scientists have thought out to make even these small mirrors non-monolithic. To enlighten the entire structure and to facilitate the manufacturing, the designers have suggested that these mirrors should be similar to a sandwich consisting of two thin layers, rigidly fastened between themselves by a open-work metal construction. According to the scientists, the remaining free space may be filled in by a light heat-insulating material.

The major thing the scientists have suggested is to reject the traditional form of a telescope, the so-called tube, in which the mirror is normally fixed on the support, an individual dome protecting the tube from the environmental impact. The Russian astronomers` design has made the body fulfil all these functions (support, placement of optical elements and protection). The body is a hollow sphere of 50 meters in diameter with an aperture slightly exceeding the mirror size. The body presents a two-layer truss shell. Its immovable lower part carries the mobile upper part with the main mirror fastened in it. Between them the so-called lodgement is placed, which easily, precisely and accurately turns the upper part with the fastened mirror.

As a result, the designers have managed to ensure unprecedented solidity, reliability and rigidity of the entire structure. In addition, such a design allows the scientists to protect the telescope from vibrations - the whole construction is non-resonant. And finally, the entire telescope turns out to be light (the weight of the mobile part being 800 tons) and inexpensive (for its class, of course), its cost making only USD 99 million.
"In principle, our AST-25 telescope is currently the most rigid, simple, inexpensive and reliable telescope in the world among similar large telescopes already being operated or under development", says Professor Sychev, one of the project designers.

Olga Maksimenko | alfa

More articles from Physics and Astronomy:

nachricht New way to write magnetic info could pave the way for hardware neural networks
21.11.2017 | Imperial College London

nachricht From Hannover around the world and to the Mars: LZH delivers laser for ExoMars 2020
21.11.2017 | Laser Zentrum Hannover e.V.

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

From Hannover around the world and to the Mars: LZH delivers laser for ExoMars 2020

21.11.2017 | Physics and Astronomy

Borophene shines alone as 2-D plasmonic material

21.11.2017 | Materials Sciences

Penn study identifies new malaria parasites in wild bonobos

21.11.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>