Canada unveils device for big space telescope

The Canadian Space Agency has unveiled a precision equipment that will be used on the James Webb Space Telescope, the successor to the Hubble. The Webb, billed as a powerful time machine capable of uncovering the origins of the universe, is scheduled for launch in 2018. Canada's contribution to the biggest space telescope ever made is a two-in-one instrument, reported Xinhua. The first part is a Fine Guidance System, which consists of two identical cameras (just in case one fails), dubbed "Canada eyes" by the University of Montreal.  It will enable the telescope to point at a celestial object within one millionth of a degree of accuracy, likened to measuring the width of a hair from five km away.

The second, a spectrometer called the Near-Infrared Imager and Slitless Spectrograph, will search for galaxies formed after the Big Bang that created the universe some 13. 7 billion years ago. It will also look for signs of life through the presence of oxygen, carbon dioxide and methane in planetary atmospheres around distant stars, and try to find new stars forming. Retired astronaut Steve MacLean, head of the Canadian Space Agency, lauded the Canadian-made technology for its capability of "unprecedented levels of precision to conduct breakthrough science on board the largest, most complex and most powerful telescope ever built". The instruments - about the size of a kitchen stove - will be delivered to the National Aeronautics and Space Administration (NASA) for integration into the Webb telescope July 30.

Replacement for the Hubble telescope

Named after the second NASA administrator who crafted the Apollo programme in the 1960s, the Webb will replace the Hubble Space Telescope, which was sent into orbit 22 years ago. Unlike the Hubble, positioned 568 km, above the Earth, the Webb will be placed 940,000 miles, or 1. 5 million km from Earth (four times the distance between the Moon and the Earth). At that distance, the Webb telescope will be "too far from Earth to be serviced by astronauts like Hubble was", noted MacLean.  "The technology simply has to work. "To observe objects billions of light years away, the Webb, equipped with a primary mirror about seven times larger than Hubble's and a tennis court-sized sunshield, will be large enough to gather very faint light to help scientists look back to a time when galaxies were forming, and cold enough to detect infrared light, or heat, emitted from distant objects while operating in a temperature of -230 degrees Celsius for five to 10 years.

By contrast, the Hubble telescope was designed to operate at 21 degrees Celsius and look at ultraviolet and visible light. About 100 times as powerful as the Hubble, the Webb will essentially take photographs of "the first stars lighting up at the beginning of the universe", said David Lizius, president of Ottawa-based Com Dev Ltd.  which built the instrumentation. "It's never been done before," he said. The technology compensates for movement by allowing scientists to take pictures with a very long exposure time - "effectively a shutter speed of a week", Lizius explained. "We will be able to go back in time and see light that left some of the very first stars not long after the beginning of the universe," he said.

IANS