After several delays, the shuttle Atlantis thundered off its Florida launch pad Friday, carrying a $617 million space observatory to be deployed into orbit. Despite this success, the U.S. space program seems to be facing some critical times and an uncertain future.

Now a decade old, the shuttle program has never lived up to the high hopes that it would serve as a glamorous but reliable "space truck" able to turn orbital space flight into a frequent and routine experience.Even discounting the Challenger disaster that canceled all launches for two years, the schedule of shuttle flights has always fallen far short of what was anticipated. Atlantis is the first shuttle to get off the ground this year out of eight originally planned.

The next logical steps in space exploration would be an orbiting space station, a permanent moon base, and finally, a flight to Mars. All would be tremendously expensive. Given the current inability of the shuttle to fly on a regular basis, even building a space station might be impossible.

Given the budget problems in Congress, some respected scientists are saying NASA is trying to do too much with too few resources and ought to scale back its manned flight program and concentrate more on unmanned rockets with smaller scientific payloads. They say manned flight takes too much money for what is accomplished and that man in space is useless. That is an old idea, but it seems to be gathering support.

The Bush administration is trying to put more emphasis on the space program, particularly the construction of the space station. But getting the money out of Congress looks more difficult all the time.

The blue ribbon science panel that suggested less emphasis on manned flight also recommended scaling back the space station to a smaller, less expensive version with half the original eight-astronaut crew. However, a committee of the National Research Council said that the smaller space station would not do the job and might as well not be built at all.

As far as Mars is concerned, there appears only one way to get there and that is in a cooperative venture with the Soviets. But at this moment, neither country can afford to go, either separately or even jointly.

At this uncertain rate, in another 10 years, America's space program is not going to look anything like that classic science fiction film "2001: A Space Odyssey."