Science: Nasa takes a nosedive

This week, the 77th space shuttle flight will take off, and the world's media will barely mention it. Shuttles go up and come down seven or eight times a year, noticed only when lives are put in danger or woodpeckers drill holes into high-tech insulation on the fuel tank.

It was not always thus. On 12 April 1981, the shuttle Columbia lifted off for the first time from Florida amid a fanfare of publicity. It was, allegedly, the dawn of a new era in space transportation, the day the space shuttle was born. Columbia was significant because it carried the hopes of a space agency that had not launched a manned spacecraft in almost six years and that was suffering from an identity crisis.

Yet by the time Columbia lifted off, the dream was tarnished. Cost overruns and technical problems had delayed the shuttle's maiden flight by two years. Nasa officials were well aware that their promises of a cheap, multi-purpose space vehicle would not be fulfilled.

As Nasa prepares to launch Endeavour on a routine mission on 19 May, it is having to come to terms with an ageing shuttle fleet, a declining workforce and budget, and falling morale.Faced with the unpalatable facts that each shuttle mission costs about $400m and no replacement vehicle will be available for the foreseeable future, Nasa's director, Daniel Goldin, has decided to privatise the shuttle programme. Over the next five years, thousands of workers will lose their jobs as responsibility for shuttle operations is transferred to a newly formed private company called United Space Alliance, a joint venture by the US space giants Lockheed Martin and Rockwell International.

Many Nasa officials and politicians now argue that the time has come to cut back on the unnecessary bureaucracy and paperwork introduced after the 1986 Challenger disaster. "When you realise it takes one million signatures to fly one shuttle flight, that does suggest to you that something is wrong," says Robert Walker, a Republican Congressman.

Despite his apparent approval of the restructuring plan, Bryan O'Connor, Nasa's deputy associate administrator for the space shuttle, resigned. He was particularly unhappy with a return to the pre-Challenger policy that made the Johnson Space Centre in Houston responsible for shuttle management instead of Nasa HQ in Washington DC. As he saw it, one of the key safety improvements post-Challenger was to make the shuttle management in Houston responsible to headquarters.

Others are unhappy with what is happening at the top, although few are prepared to speak out openly. One who did make his feelings known was Jose Garcia, a middle manager at Kennedy Space Centre. "This isn't like a cafeteria that you can just turn over to the private sector," he says bitterly.

One major concern is that the new shuttle operators may feel obliged to cut corners to meetlaunch targets. With potential cost savings of $1bn a year, Mr Goldin is unrepentant, dismissing the idea of a private corporation risking lives to increase profits. "With Lockheed, Martin and Rockwell we have two experienced companies that clearly understand how to operate the shuttle safely," he says.

"I don't know why there is this concern about a private contractor operating the shuttle. Do you want the government operating the aircraft we fly on? I don't."

James Adamson, chief operating officer of United Space Alliance, has been equally keen to reassure the space community. "Safety takes precedence over everything. We are discussing an incentive-based contract to do three things: fly safely, deliver the product - which would be flying on time - and make the operation more efficient."

Although there have been no craft or crew lost in the past 10 years, the question of shuttle safety is far from academic. A recent report by Nasa states that there is a 50 per cent chance of another catastrophe before the year 2015. The report concludes that the most likely scenario is a launch failure caused by the explosion of a shuttle main engine. Another possibility is a crash on landing caused by failure of landing gear and brakes.

Meanwhile, shuttle flights continue to throw up their share of scares and technical problems. A launch abort was barely avoided during the February launch of STS-75 when one engine's pressure gauge read only 45 per cent and an amber warning light appeared in the cockpit. The crew was preparing to attempt a dangerous return to Florida when ground controllers confirmed that the engines were running properly.

On the most recent launch in March, the orbiter Atlantis sprang a leak in the hydraulic system which supplies power to its wing flaps, rudder and landing gear. Mission controllers had to consider bringing the craft home early. Then the landing had to be delayed for a day when sensors wrongly reported that the two cargo bay doors had jammed shut. This could have caused overheating and severe damage to the shuttle's electronics. The shuttle eventually limped home with several thrusters non-operational.

"There's going to be another accident," says Peter Aldridge, a former Air Force Secretary. Richard Truly, a Nasa administrator and former astronaut, agrees. "Sooner or later, something's going to happen ... It could be a nose-wheel failure."

Could Nasa survive another shuttle disaster? Today, Nasa is relying on the shuttle to build and maintain a $30bn international space station which is scheduled for construction between 1997 and 2002.

"To me. it's not a political issue," says Goldin. "It is a statement about the will of the American people."

Next week: Europe reaches for the skies with a new heavy rocket launcher.