The aftermath of a solar flare

Ground controllers were putting the Solar and Heliospheric Observatory (SOHO) through routine tests when a safeguard program started unexpectedly. This was designed to help the spacecraft find the correct direction in space if it ever lost its orientation towards the Sun.

Scientists are now desperately trying to regain control of the spacecraft. "We are sending commands and streams of data, but so far the baby does not talk back to us," said Franco Bonacina, a spokesman for the European Space Agency (Esa) in Paris.

SOHO is a joint project of Nasa and Esa. It was launched in December 1995 and has been monitoring the Sun with 11 different instruments from a vantage point 1.5 million kilometres closer to the Sun than the Earth.

Superhot gas thrown into space

So far the mission has been a spectacular success, revealing new details of the motions of the Sun's surface and magnetic activity of its hot, thin atmosphere.

This success persuaded planners to extend its life - originally due to end last spring - until 2003. This would have allowed the spacecraft to observe the Sun as its 11-year cycle of activity peaks.

The spacecraft may be spinning out of control. This would cause the crafts batteries to discharge since the solar panels would no longer point toward the Sun. That would dim hopes for re-establishing contact and it would drift out of stable orbit.