CAPE CANAVERAL, Fla. (AP) _ NASA and its space partners, in an unprecedented show of support, pledged Thursday to build an international space station on time and within budget.

''We have an executable program,'' NASA space station director Wilbur Trafton said at a news conference outlining plans for the orbiting laboratory. ''We expect problems, but we've got the team in place that can tackle these problems.''

The space station unveiled Thursday was NASA's seventh version. Ten station program managers discussed the project following a system design review at Johnson Space Center in Houston - they represented NASA, the European Space Agency and the space agencies of Italy, Canada, Japan and, for the first time, Russia.

Russia became a full partner late last year in the international space station already planned - and replanned - by the other countries. But some members of Congress and many others fear Russia's economic and political uncertainties could jeopardize the project.

Dan Tam, NASA's space station business manager, said he's confident Congress and others will buy the program once they see ''we indeed have a different way of doing business.'' This includes a streamlined program, specific goals and a firm design.

Provided Congress approves funding, NASA and its Russian counterpart expect to start building the orbiting laboratory in 1997, after America's shuttles dock 10 times with Russia's aging space station Mir.

Sixteen U.S. shuttle flights and 13 Russian space flights will be required over five years to build the station, officials said. In addition, up to five flights will be needed each year to supply fuel for raising the station's orbit.

That's 54 flights right there.

Trafton said NASA was prepared to go it alone if Russia or any other country pulled out. By the same token, U.S. space station parts could be transferred to Russian rockets for launch if the shuttle fleet was grounded because of an accident, said Bill Shepherd, deputy program manager.

''We are working contingency plans,'' Trafton said. ''I think we're being prudent program managers here. ... We feel like we're going to have a space station, and we're going to launch in December 1997.''

The station, dubbed Alpha but still awaiting an official name, should be completed in 2002 and house six people. NASA said it will be bigger and cost the United States less than what had been planned under the old space station Freedom program.

Trafton said NASA will use 75 percent of the hardware, drawings and other items already planned for space station Freedom.

As for costs, NASA insisted they will not exceed the $2.1 billion annual spending limit set by the Office of Management and Budget. The latest cost estimate through completion is $17.4 billion, in addition to the $10 billion already spent. That doesn't include shuttle launch costs or foreign investment.

Add about $3 billion from the European Space Agency by the time the station is completed, $1 billion from Canada, $400 million from Italy and $3 billion from Japan and the cost is up to $35 billion and counting. The Russian space agency's representative, Alexander Botvinko, said he could not provide a cost estimate.

Many issues remain unresolved.

NASA is struggling to reduce the amount of spacewalking time needed to build the station and maintain it during its 10-year lifetime. Current plans call for more than 400 hours of spacewalking to build the station, but NASA wants to get that below the 365 hours required under the old space station program.

And a spacesuit common to both the United States and Russia must be developed, although that doesn't have to be done immediately, Shepherd said.

Tam said for the first time in the 10-year history of the space station program, ''we feel much better today than we've ever felt.'' The European, Canadian and Japanese representatives agreed with some hesitation.

''We're in it for the long haul. We want to see this program succeed,'' said Derek Deil, the European Space Agency's station manager.

NASA said joint U.S.-Russian space flights now through 1997 will provide the necessary experience for building a joint station and reduce risks.

U.S. astronauts are to spend a total of 24 months on Mir beginning in 1995. At the same time, Russian cosmonauts will fly on shuttles. The first time a cosmonaut flew on a U.S. shuttle was last month, on Discovery.

As NASA was hashing out station details, the Aerospace Safety Advisory Panel urged the U.S. space agency to get a quick but thorough understanding of the workings of the Russian space program: its testing procedures, equipment design and policies on having backup systems.