Electric fault nearly blinds flying telescope

Press, 21 November 1987, Page 3

Electric fault nearly blinds flying telescope

By

NIGEL MALTHUS

A minor electrical fault at 41,000 ft over the Tasman Sea, came close to blinding the world’s only flying telescope early yesterday morning. The fault upset the tracking mechanism of N.A.S.A.’s muiti-million dollar Gerard P. Kuiper Airborne Observatory, half-way through a sevenhour flight investigating a supernova in the southern sky.

Technicians were about to attempt to fix a failed power supply by soldering in a penlight battery when the fault cleared and the flight continued without further incident.

It was the closest they had come to having to abort a mission, said the mission director, Mr Carl Gillespie. At that stage thw astronomers aboard had nearly completed a three-hour look at the supernova, on the longest leg of the flight. They still had to take measurements from other stars, important for the proper calibration of their instruments.

Despite the mishap, the astronomers say they have been pleasantly surprised by the quality of their data. They say there is a good chance the aircraft will be brought back to Christchurch for further observations of the supernova next year. Their target is SN 1987 A, a star which was seen to explode in February this year, and is being studied for clues as to how the universe formed.

Such supemovae are thought to be the only way in which the heavier elements which make up the Earth, were formed from smaller atoms.

Dr Harvey Moseley, who headed one of four experimental teams, said his data had confirmed the presence of iron, and

other heavy elements that will be identified when the data is fully analysed. Theoreticians had proposed various models of how a supernova explosion took place, said Dr Moseley. The experiments would show which of the theories was mostly likely, he said.

SN 1987 A is of particular interest because it is the first “nearby” supernova to be discovered since the invention of the telescope. “Nearby,” in astronomical circles, means that the event occurred more than 150,000 years ago, and it has taken that long for light to reach the Earth. Visible only from the southern hemisphere, the supernova was first seen from a Chilean observatory on February 23. The exploding gases and dust have expanded to an observed size now, greater than the solar system. It is now starting to fade to about 10 per cent of its brightness in April and May, when it was visible to the naked eye. The observatory is a Star Lifter cargo plane fitted with a 36in reflecting telescope, set up specifically to study light in the infra-red band, rather than the visible spectrum.

It is named after a Dutch-American astronomer who first proposed using a flying telescope for infra-red mapping of the heavens. Faint infrared rays do not reach the earth’s surface, because they are absorbed by atmospheric moisture. Flying at 41,000 ft, the telescope is above about 80 per cent of the atmosphere, and more importantly, above 95 to 99 per cent of the moisture. The aircraft is used all over the world, and was last in Christchurch to look at Halley’s Comet.