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 quantum liquid crystals may play role in future of computers
21.04.2017 | California Institute of Technology

nachricht Light rays from a supernova bent by the curvature of space-time around a galaxy
21.04.2017 | Stockholm University

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: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

Molecular libraries for organic light-emitting diodes

24.04.2017 | Life Sciences

Research sheds new light on forces that threaten sensitive coastlines

24.04.2017 | Earth Sciences

Making lightweight construction suitable for series production

24.04.2017 | Machine Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>