Aisling Irwin looks at the aftermath of the Ariane V explosion. Space scientists and plasma physicists were yesterday counting the cost of the exploded Cluster mission in terms of seriously damaged careers, potential job losses and repercussions for other space missions.

The disintegration of Cluster just after its launch on Tuesday afternoon has removed at a stroke the main source of data for many scientists' work for the next six years. Of the 11 instruments on board each of the four identical satellites, United Kingdom scientists were principal investigators for four. Eight UK centres were heavily involved in the instruments' design and hundreds of UK scientists were preparing to work on the data that Cluster would have sent back about the effect of the sun on the earth's magnetic field.

Scientists this week estimated that a repeat mission would cost only half as much again, since so much of the research and design work had already been done. The Particle Physics and Astronomy Research Council said this week that although it would be meeting to discuss whether there was any hope of retrieving the mission, it had no spare money to help finance a new Cluster mission. One spare version of each instrument had been built, but the advantage of Cluster was that it was composed of four identical satellites to enable everything to be examined from four different points.

Scientists also expressed fears that grants for doing science with the Cluster data, many of which were announced last spring, might be withdrawn. Others were uncertain about the legal status and future of jobs that had been awarded recently on the basis of these grants. One scientist said: "We just don't know what is going to happen. Things are very uncertain."

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The mission, one of the European Space Agency's four cornerstone missions, cost the UK Pounds 50 million, of which Pounds 35 million went to the general European cost of building the basic satellite and ground control. Much of this money was returned to UK industry via industrial contracts. Some Pounds 12.3 million financed the UK contribution to the building of instruments. A further Pounds 3.4 million paid for the giant data handling facility at the Rutherford Appleton Laboratory that was to have masterminded processing the masses of data from the 44 instruments and its dissemination to scientists in Europe and the United States.

At the 150-strong Mullard Space Science Laboratory, part of University College London, Alan Johnstone was principal investigator for the Pounds 6 million instrument, Peace, which two scientists in the laboratory had been working on for 10 years. Nick Flowers, a member of the Cluster operations team, said that there were to have been about six scientists working full time for the next few years helping control the instrument and analysing the data coming back. Thirty scientists were directly involved with the project.

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"It was pretty much a cornerstone mission for our laboratory as well as for ESA," he said.

At the Rutherford Appleton Laboratory, Peter Vaughan, whose work masterminding the data handling facility was to have begun two days ago, said that ten scientists were to have worked for him for the next five and a half years on Cluster data. Some are funded by the European Space Technology Centre, part of ESA, others by PPARC. He said he was examining the possibility of redeploying them.

The Cluster disaster will also affect large numbers of scientists who were hoping to mix its results with other key projects investigating the effect of the sun on the earth. Cluster was to be run in tandem with Soho, a satellite balanced between the sun and Earth successfully launched last November. Now the important synergy between the two has been lost.

At Leicester University, science minister Ian Taylor inaugurated the Pounds 1 million Cutlass project last week - two radar stations based in Finland and Iceland that are examining the effect of the sun on the foot of the earth's magnetic field 100km to 300km above the earth.

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What Cluster found out about the effect of the sun tens of thousands of kilometres higher up was to have been matched with effects detected by Cutlass lower down. Two scientists at Leicester were to devote all their time to examining Cluster/Cutlass interactions.

Mark Lester, senior lecturer in the physics department of Leicester University and a Cutlass investigator, said: "It was going to be collaborative studies, which are very important. This represented a unique opportunity. It can't be replaced."

PPARC officials will meet soon to decide what to do with the millions of pounds allocated for further Cluster research.

Yesterday UK scientists were flying back from Kourou in French Guiana where they witnessed Cluster's launch on the Ariane V space rocket.

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