Satellite failure upsets research

Press, 6 September 1989, Page 15

Satellite failure upsets research

By NIGEL MALTHUS Research projects by three University of Canterbury astronomers have been scuttled by the failure of a European Space Agency satellite launched last month.

The Hipparcos satellite was launched on August 9, but failed to reach its proper orbit, and is now expected to have an operational life of only six months. Dr William Tobin, of the university’s physics department, said the satellite was intended to measure the positions of stars and their movement over time which was “exceedingly difficult” to

do accurately from Earth, since they moved so slowly.

Dr Tobin said there were two types of motion — “proper” motion, caused by the stars’ movement through the universe, and "parallax” motion, their perceived change in position because of the Earth’s annual orbit around the Sun.

It was difficult to distinguish one from the other so it was important the satellite stay in operation for more than a year. Hipparcos, the first satellite of its type, was expected to have provided positions 100 times more

accurately than achieveable from Earth. Its data now might be only slightly better.

“All the exciting new stuff is down the tube,” Dr Tobin said.

Dr Tobin’s project was to investigate certain anomalous stars to determine whether they were near or far from the solar system.

Drs John Hearnshaw and Peter Cottrell had a programme investigating the motion of nearby stars.

Dr Tobin said the mission had been a long-term project. He had applied in 1982 for observation time on the satellite.