Leading Article: The quest must go on

IT WILL be very sad if the 450 million-mile, year-long, dollars 980m mission of Nasa's Mars Observer spacecraft proves to have been in vain. The spacecraft fell silent on Saturday as it was carrying out commands to insert itself into orbit 234 miles above the Red Planet. It was intended to study Martian terrain, climate and weather, and was armed with instruments that included a camera capable of pinpointing a car-sized object. Yesterday no one knew what had happened to the spacecraft, and hopes that it could be reactivated were fading.

It looks like a severe and expensive setback, but not a terminal one. The universe is today what the oceans were to mankind five centuries ago. Because it is there, and because it is man's destiny to go on probing its mysteries, it is unthinkable that attempts to explore it should cease. The science-fiction writer Arthur C Clarke may have been going a bit far when he said in 1950: 'The challenge of the great spaces between the worlds is a stupendous one; but if we fail to meet it, the story of our race will be drawing to its close.' Yet the essence of his message remains valid.

One distant day it could even prove to be literally true: our own planet could become so polluted or overcrowded that the colonisation of another planet, or of space itself, becomes essential.

That man's exploitation of space to date has already revolutionised our daily lives is indisputable. Communications satellites have linked all corners of the earth (see also below). Spy satellites have facilitated the monitoring of arms build- ups and troop movements, and thus made the world a safer place. Earth observation satellites are contributing to the detection of natural resources and the monitoring of their misuse as manifested by global pollution.

True, these giant strides were greatly accelerated by the Cold War: it was the Soviet Union that, traumatically for the United States, put the first satellite into orbit in 1957, and the first human being four years later. The Americans' most successful riposte was the Apollo mission, resulting in the landing of two astronauts on the Moon in 1969. The Russians still had their lead in heavy rocket launchers and space stations when President George Bush announced the Mars programme in July 1989. Its climax was to be the landing of a man on Mars on the 50th anniversary of the epic walk on the surface of the Moon.

The Cold War ended shortly thereafter. Taking into account the seemingly modest scientific return from lunar exploration, the case for expensively probing Mars might seem to have been drastically weakened. Nasa's use of its resources has come in for much criticism, and it has had at least its share of disasters. But at an annual dollars 14bn, its budget does not, arguably, bulk large beside, say, US defence spending of dollars 290bn. Astronautics is a fiendishly complicated and expensive business. As long as mankind aspires to solve the riddles of the universe, the quest for knowledge must go on.