The heads of the American and Russian space agencies have found that they have at least one thing in common: Neither has enough money to fulfill their cosmic dreams.


Perennial shortages of government funding have helped inspire both the United States and Russia to agree to coordinate an unmanned mission to Mars and to cooperate on other flights, according to the heads of the two space agencies.


"We know that space has no limits, but unfortunately the resources of man that explores it does have limits", said Yury Koptev, general director of the Russian Space Agency.


In an agreement signed Monday, both Russia and America will place astronauts on the other nation's ships in 1993 and 1995, and spacecraft from the two sides wil link in 1995. Both nations will also coordinate a robotic flight to Mars in 1994.


By American standards, Russian spending on space exploration has fallen to miserly levels. Russia will spend 8. 7 billion rubles ($25 million) for its space program this year, Koptev told The Moscow Times.


Even though NASA will spend about $14 billion on its space program this year, money is a problem for the Americans too, Daniel Goldin, the space agency's director said at a press conference Monday.


One way to save money is to make equipment of different nations compatible, so that, for example, a Russian and American ship can easily dock in space, Goldin said.


This capability will be demonstrated in a 1995 mission in which an American space shuttle will rendezvous with a Russian Mir orbiter, and then carry the passengers - an American and two Russians - back to earth.


The accord signed Monday may also prove a valuable beginning to what would be the most expensive space mission ever mounted: a manned journey to Mars.


Vladimir Durnev, a deputy director of space operations at Russia's Defense Ministry, estimated the cost of a manned Mars mission at $150 billion dollars. "If we work together, we can do it quicker and more cheaply", he said.