Another small step for Mir, and a giant gamble for Nasa

The US space shuttle Atlantis has docked safely with Mir, delivering a replacement American astronaut to the troubled space station. Nasa's decision to send the American on a four-month mission aboard the orbiting Russian craft flew in the face of opposition from Congress. John Carlin examines whether the benefits of the exercise really do outweigh the risks.

The value of the mission is negligible; the cost is enormous; the risks terrifying. But the scientists at Nasa are not going to let a little thing like logic get in the way of a wonderful adventure in space.

Frank Culbertson, Nasa's manager of joint US-Russian space activities, poured scorn on the faint-hearts in Congress when he said: "I'm worried about whether the country still has the courage for high technology projects like this."

Valery Ryumin, director of the Russian space agency, was more blunt. The Americans, he said, will look like "sunshine space explorers" if they "head for the hills" whenever difficulties arise.

The doubters in the US Congress are sadly lacking in the John Wayne spirit, Mr Ryumin seemed to be saying. But the difficulties encountered in the last year by Mir, the pride of what remains of the Russian space programme, have not been inconsiderable. A fire in February; two serious collisions; power failures; computer breakdowns. No one knows what further perils David Wolf, the new American astronaut, and his two Russian colleagues will face in the coming months.

And as for the science, little more is likely to be learnt to advance human knowledge. One purpose of the mission was to establish whether the space shuttle could dock successfully with an orbiting space station. Another has been to examine the effects on the human body of prolonged weightlessness in space.

It has been important to answer these questions, because next year construction begins on an International Space Station with the participation of more than a dozen countries. The Mir pioneers have carved a path for those that will follow.

But James Lovell, an astronaut who came close to death aboard the Apollo 13 mission, has observed that after the last five missions all the information that could possibly have been obtained has been obtained. "Mir has done an exceptionally fine job," Mr Lovell said recently. "Now it's time to give it a very respectful retirement."

The consensus among scientists not involved with Nasa has been the same. "It's got nothing to do with science any more," said John Pike, director of the space policy project at the Federation of American Scientists.

All of which pointed James Sensenbrenner, the Republican chairman of the House of Representatives' science committee, to one conclusion: "The risks have increased and the science has dropped off."

Mr Sensenbrenner said at a House hearing on the Mir mission last week that Daniel Goldin, head of Nasa, would be "putting his reputation on the line" if he gave the go-ahead for astronaut Wolf's mission.

Democrats in Congress have echoed these sentiments, washing their hands of any responsibility if anything goes wrong, pre-emptively placing the blame for what one described as a potential "suicide mission" squarely on Mr Goldin's shoulders.

A congressional researcher summed up the anxiety on Capitol Hill in testimony before last week's hearing when she wondered what would happen in the event of a tragedy aboard Mir. "I think they would wonder why it was that Nasa had sent an astronaut up there - what was it that the astronaut was going to do up there that was so important and so valuable that they would risk his life."

It does not require too much of a leap of the imagination to guess that the astronaut himself, who has made it plain he is prepared to face any risk for his shot at glory, and all at Nasa who have put their heart and soul into the mission, view the congress members in Washington in much the way most of the American public view them: as weasels whose utterances are determined overwhelmingly by calculations of political loss and gain.

The likes of Mr Sensenbrenner risk nothing by expressing their doubts about the mission, while leaving themselves the opportunity to tell voters "we told you so" in the event of things going badly wrong.

Mr Goldin, in another discreet jibe at Washington, said shortly before Atlantis lifted off on Thursday that his decision to continue joint participation aboard Mir "should not be based on emotions or politics".

No. It is based on a vision of world peace, powerfully dramatised by former enemies coming together bravely to confront a common danger, and on the sense of adventure and romance that fires the scientists at Nasa.

But the cynics in Washington cannot understand.