Nations in Western Europe are close to deciding whether to join in the United States' project to build a large permanently manned space station in the early 1990s.
The 11 member-countries of the Paris-based European Space Agency are to convene a special meeting in January or February at which ministers will decide how to respond to the US offer.
The American government wants Western Europe to contribute up to $2 billion to add to the $8 billion that President Ronald Reagan has already committed to the project.
In return, government departments and companies in Western Europe would share in planning and building the orbiting base, which could house laboratories for experiments in materials processing and act as a docking platform for satellites.
Observers say Western Europe is almost certain to join the project - the question mark is over the resources the European countries feel they can put into the program. Government leaders and space scientists think that to spurn the invitation would be to turn down the chance to gain experience in areas of technology that may become vitally important by the end of the century.
But with much of Western Europe affected by government spending contraints, the countries may be unable to contribute a sum as large as the United States would like.
France, West Germany, and Italy are the keenest to collaborate. The latter two countries have joined forces in designing a ''mini'' space station called Columbus.
If taken over by the rest of Europe as a project of the European Space Agency , Columbus could form the Continent's share of the US space station plan. It would be a separate module that could be bolted into the core of the main American orbiting platform.
France, meanwhile, is eager to join in on the grounds that participation could give a boost to its own plans in manned space flight.
The US has said that not only the shuttle, but also European-built flight vehicles such as derivatives of the Ariane rocket will be allowed to send people and cargo to the station.
As the leader of the Ariane program, France plans to convert the unmanned rocket to a vehicle called Hermes that could carry a crew of up to five and thus act as a docking craft with space platforms.
The dilemma over the space station is particularly acute in Britain, where public spending on space projects is much less than in France and West Germany.
Officials in the United Kingdom estimate the British government would have to send some $300 million over eight years. But this would entail a rise in Britain's annual space budget of some 40 percent - an increase that ministers are unlikely to contemplate at a time of state funding constraints.
Another problem is that of time. The US plans to start detailed designs for the station by mid 1985. If Western Europe cannot make up its mind by then on what part to play, the program will go ahead without it.
As a British official remarked: ''It's as though we are having to race to get into a bus - and the bus is not stationary but is moving.''
A warning that Western Europe will miss out if it fails to go along with the US on the space project came recently from the chairman of the European Space Agency, Dr. Harry Atkinson.
A British civil servant who is director of science at Britain's Science and Engineering Research Council, Dr. Atkinson took over this part-time job this past summer.
He said that if Western Europe decides against participation, it may find it hard to stay competitive on the world scene in an important area of technology.