The M55-Geophysica spyplane was once the pride of the Soviet secret services, unknown outside intelligence circles and unlisted in aircraft reference works. But the hush-hush high-altitude aircraft has come out of the shadows, if not out of the cold. The M55 will this month complete a series of scientific flights over Antarctica in an Italian-led project to find out more about the hole in the earth's ozone layer, and help predict its likely pace of recovery.