THE launch March 14 of an American astronaut aboard a Russian spacecraft bound for the space station Mir is the latest symbol of international cooperation in orbit.
From Moscow to Washington, however, national space programs are having a hard time escaping the gravitational pull of tight budgets. Some analysts even suggest that the United States-led international space station may be the last cooperative manned spaceflight project for the foreseeable future.
''Every spacefaring nation is grappling with budget problems,'' says Marcia Smith, who tracks international space efforts for the Library of Congress. ''Cooperation can help, but you still need to reach a critical mass, especially for new projects.'' That critical mass, she adds, is getting harder and harder to achieve.
The fiscal restraints are evident in several countries:
*In Russia, which faces crushing economic problems, space planners are warning of failing communication satellites and a limping Mir space station. The Russian Space Agency's director-general, Yuri Koptev, told the Duma last month that a lack of money also threatens the shuttle-Mir program.
*In Europe, key members of the European Space Agency (ESA) are questioning their contributions to ESA's efforts. France, Germany, and Italy are discussing caps on spending for manned spaceflight, as well as stretching out the spending. Instead of spending $4.8 billion between 1995 and 2003, Germany has suggested $2.5 billion between 1996 and 2000.
*In Canada, Ottawa is throttling back on its small space program. It is planning to cut spending by 12 percent over the next 10 years, although its contribution to the space station remains stable. The money will be cut from other activities.
*And in the United States, the National Aeronautics and Space Administration is undergoing what Ms. Garver calls ''the most radical change in its budget since the mid-1970s,'' when the Apollo program came to a close. ''After the 1970s, we did less in space. Now we're trying to [hold to our current programs], but with less money.''
Given the huge costs of high-profile spaceflight projects, spreading that cost among several nations stimulates cooperation, notes John Logsdon, director of the Space Policy Institute at George Washington University in Washington, D.C. ''On the other hand,'' he adds, ''the constant re-evaluation of programs makes cooperation risky.''
Once symbols of technological prowess and national prestige, space programs long seemed to defy those who asked: Wouldn't the money we spend in space be better spent solving problems on the ground or not spent at all? But now such questions are being listened to.
Several factors have combined to bring space programs back down to earth -- not the least of which is the end of the cold war.
''The US and Russian programs were driven by the cold war. Europe and Japan developed their own space programs so that they wouldn't fall behind,'' says Dr. Logsdon. ''Countries now are reassessing their commitments. They're asking: Why are we doing these things at this level of expenditure?''
In addition, public attitudes have shifted.
''In the early days, NASA didn't have to persuade people that space was interesting. As spaceflight has become more successful, it has become more normal. You don't see launch- by-launch countdown coverage at the Kennedy Space Center anymore,'' says Jon Miller, vice president of the Chicago Academy of Sciences and professor of political science at Northern Illinois University.
As a result, he continues, spaceflight's share in the marketplace for people's time and attention has fallen considerably. ''People say that they don't want to kill the space program; but they also say it shouldn't be exempt from belt-tightening.''
In every country, Mr. Miller says, politicians are looking at human resources and infrastructure. ''But they're thinking in old terms; space is now part of the infrastructure.''
Perils-of-Pauline funding and its effect on the future help explain why the US is putting a full-court press on ESA, which has become the target of a high-profile US lobbying campaign in support of the space station. Meanwhile, the Germans also are balking at ESA's plan to spend $1.6 billion over five years to support the Ariane 5 rocket, the latest in ESA's stable of commercial launchers.
In part to help the Russians, the US is spending $400 million for the shuttle-Mir program as well as for support of Russia's space-station contribution. Russia's Mr. Koptev said that his country's manned spaceflight program is getting only a startling 2 percent, roughly, of the funding it needs for 1995. ''It's incredible that they still have a space program at all,'' says Lori Garver, executive director of the National Space Society, based in Washington, D.C.
Speaking of the future of international cooperation in space, George Washington University's Logsdon says: ''First we have to do the space station, which won't be finished for another seven years,'' adding that if it succeeds, it will open the way for further efforts.