CRI听力:World's largest radio telescope completes installation

The construction of the project was started in 2011 with an investment of 1.2-billion yuan, or about 180 million US dollars.

The 500 metre Aperture Spherical Telescope, or FAST, is the size of 30 football fields.

It's located in a hollow that was formed 45 million years ago with the collapse of a karst cave in Pingtang county. Experts describe the hollow as an extremely 'radio-quiet' site.

The firm working on the project, the Wuchuang Shipbuilding Industry Group, used a unique air transfer and flexible hoisting technique to speed up the progress of the scheme.

Wang Weiling, deputy director of the company, says great care has been taken in installing the panels.

"FAST has 4,450 triangular panels. There was no risk of damage during the hoisting process. At the site, our company undertook the accurate installation of every panel, and we improved the technology involved in transferring the panels and positioning them. We have installed these 4,450 panels accurately on over 2,000 spherical fulcrums. From research and development to production, It took us over two years to complete the mission."

The reflector panel is the core device that decides the telescope's radar coverage and detection precision. With a side length of 10 to 12 meters, each reflector panel is composed of 100 triangles each made with extreme precision to a matter of milimetres.

Zheng Yuanpeng, chief designer of the reflector panel, explains their unique design.

"We can see that there are lots of holes on the reflector panels so they can reduce over 50 percent of wind. These holes can enable rainwater to permeate and will reduce aerodynamic drag. It has another advantage, in that it allows the sun to shine through, so plants can grow as before. It's very eco-friendly."

Chinese experts say the telescope will help scientists find more pulsars, which will help them gain a greater understanding of the "big bang" at the very beginnings of the universe.

"Pulsars are neutron stars that send out radio pulses. It is highly-dense and highly-magnetic matter that cannot be found on earth."

Researchers with China's National Astronomical Observatories say the telescope should be able to detect radio signals from more than 1,000 light years away, making it the most sensitive radio telescope in human history.

The telescope, which has taken about five years to build, is expected to begin full operation in September, following a period of debugging work and testing.

The telescope now dwarfs Puerto Rico's Arecibo Observatory, which is 300 meters in diameter. It will also be 10 times more sensitive than the steerable 100-meter telescope near Bonn, Germany.

For CRI, I'm Linda Mills.