The United States has a new space policy that looks beyond the international space station. President Bush's new directive to return astronauts to the moon between 2015 and 2020 defines an end to U.S. participation in the research outpost. VOA's David McAlary examines what this might mean for the 16 nation partnership that was formed around space station construction and research.

The space station's days are limited even before it is completely built. Construction awaits rehabilitation of the U.S. space shuttle fleet, grounded after the Columbia tragedy last year. Nevertheless, President Bush says the United States will finish its work on the station in 2010. He notes that the U.S. commitment to its 15 partner countries will have been fulfilled.

But what happens to the orbiting research outpost after that?

The head of the U.S. space agency NASA, Sean O'Keefe, is vague about this. "The objective will be to continue the shuttle program with the objective of completing the international space station by the end of the decade and to retire the shuttle at that time," he said. "Consistent with that, the international space station will continue to operate throughout this period and into the next decade."

But for how long into the next decade?

"That's going to have to come out in the detailed discussion of where do we go with the space station after construction is completed," answers Marcia Smith, a space policy expert with the research branch of the U.S. Congress. She says Mr. Bush's new space exploration plan shortens the space station schedule the 15 partner nations had expected, even though the president says Washington will have met its commitment to them by 2010.

"The expectation had been that after construction was completed, it would be operated for another 10 years, [and] that the U.S. space shuttle would be available to take cargo back and forth," Ms. Smith went on to say. "With the announcement that the shuttle will be discontinued in 2010, I think it will leave the partners somewhat at a loss to know what's going to happen with the space station, and how they are going to get their experiments back and forth after 2010 when the shuttle is no longer available."

While the 15 nations await details, NASA says they are considering Mr. Bush's invitation to share what he called the challenges and opportunities of his new space program. NASA Administrator O'Keefe says the space station partners are interested in discussing ways to participate. He says foreign involvement could be high.

"It is very much going to be a U.S.-led endeavor. That's our intent," he pointed out. "To the extent we can do this collaboratively, cooperatively, and in partnering with international participation, we are encouraged to do so. There is enthusiasm from our partners in examining ways they can do that productively."

Yet President Bush did not limit his invitation to just the 15 space station partners. "The vision I outline today is a journey, not a race, and I call on other nations to join us on this journey in a spirit of cooperation and friendship," he said.

Does this mean China would be welcome to take part? Beijing has just become a space power after sending its first astronaut into orbit. It, too, hopes to reach the moon eventually.

"As far as I know, the [Bush] administration isn't ruling in or ruling out any countries at this point," said Ms. Smith of the U.S. Congressional Research Service. "China has a very frugal space program. Although people talk about how China wants to send people to the moon, when you look at the Chinese accounts of this, it is not something they plan to do anytime soon. So if they were to do it by themselves, I'm not sure that they would be moving out all that quickly, but I wouldn't be surprised if they were interested in joining an international effort to do it."

President Bush outlined his vision for America's future in space in very broad terms. It will take years for details to unfold. In the meantime, the United States is still dependent on the 23-year-old space shuttle and fledgling space station for research projects that will help the country realize its new exploration goals.