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 Significantly more productivity in USP lasers
06.12.2016 | Fraunhofer-Institut für Lasertechnik ILT

nachricht Shape matters when light meets atom
05.12.2016 | Centre for Quantum Technologies at the National University of Singapore

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: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Simple processing technique could cut cost of organic PV and wearable electronics

06.12.2016 | Materials Sciences

3-D printed kidney phantoms aid nuclear medicine dosing calibration

06.12.2016 | Medical Engineering

Robot on demand: Mobile machining of aircraft components with high precision

06.12.2016 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>