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 Hope to discover sure signs of life on Mars? New research says look for the element vanadium
22.09.2017 | University of Kansas

nachricht Calculating quietness
22.09.2017 | Forschungszentrum MATHEON ECMath

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: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Rainbow colors reveal cell history: Uncovering β-cell heterogeneity

22.09.2017 | Life Sciences

Penn first in world to treat patient with new radiation technology

22.09.2017 | Medical Engineering

Calculating quietness

22.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>