Even today, it is worth sending explorers into space

"They all laughed at Wilbur and his brother/ When they said that man could fly" (in Ira Gershwin's famous lyric). They all laughed, too, back in 1981, when the ungainly space shuttle fired off from Florida on its first mission to space and returned to New Mexico with several of its protective tiles missing or blackened. What was the point, it was asked again and again, of sending a manned, reusable vehicle into space? It would soon be out of date, and it would prove much more expensive than cheaper unmanned rockets for launching satellites.

"They all laughed at Wilbur and his brother/ When they said that man could fly" (in Ira Gershwin's famous lyric). They all laughed, too, back in 1981, when the ungainly space shuttle fired off from Florida on its first mission to space and returned to New Mexico with several of its protective tiles missing or blackened. What was the point, it was asked again and again, of sending a manned, reusable vehicle into space? It would soon be out of date, and it would prove much more expensive than cheaper unmanned rockets for launching satellites.

The 100th launch of the shuttle provides a moment to take stock. First, the technology has lasted nearly two decades, although the design had to be revamped after the 25th shuttle launch, the disastrous Challenger mission, exploded in 1986. Second, the shuttle has enabled much useful repair work to be done on orbiting satellites, from boosting them into higher, more stable orbits to, most notably, replacing the defective mirror in the Hubble Space Telescope. And although the shuttle is American, Nasa has trained and utilised astronauts from many countries, with the consequence that this particular technology has always seemed something of a world-wide adventure.

The arguments against utilising the expensive technology associated with manned space travel are now being repeated over the construction of a permanent orbiting space station. Yesterday's mission by the space shuttle Discovery, flown by four Americans and a Japanese, took with it two new pieces of kit for the embryonic $60bn space station. That project, too, is an international one, sponsored by the United States, Russia, Europe, Japan and Canada.

The success of the manned shuttle missions, though, have shown that there is no substitute for human intelligence in space. Robotics are simply not sophisticated enough to solve the unpredictable problems that arise. The floating space station will not only be a permanent zero-gravity laboratory, but it will test the possibilities of putting people in permanent bases, first on the Moon, and then the planets, where the possibilities for mining minerals and making new discoveries are endless.

One of the astronauts on Discovery, space-walker Bill McArthur, alive to both the romance and history of aviation, has taken with him a piece of fabric from the Wright flyer that took off from Kitty Hawk, North Carolina, in 1903. His gesture is aptly symbolic of the bold thrill of escaping our planet's surface. In Gershwin's words: "Ho ho ho/ Who's got the last laugh now?"