US space program is only as good as its launch rocket fleet

NASA's frustrating delays as it meticulously prepares to refly the space shuttles dramatize the fact that United States space ambitions are hostage to its rocket fleet. The degree of reliable access to space limits what the US can do in space, regardless of its stated goals. It's time to match goals and launch capability, as the congressional Office of Technology Assessment (OTA) points out in its recent report on launch options.

With four shuttles and improved versions of the Atlas-Centaur, Delta, and Titan rockets commercially available, the US could carry on a space program at the pre-Challenger level. That includes building the proposed space station . But OTA notes that it wouldn't bring the 90 percent cut in launch costs needed to orbit President Reagan's ``star wars'' defense system or carry through an ambitious civil program aimed ultimately, for example, at a moon base or a manned mission to Mars.

Also, The planned system would not do much to improve launch reliability. You have only to watch NASA's struggles to get back into orbit to agree with OTA that ``the existing launch systems lack `resilience,' that is, they do not recover rapidly from failure.''

In this sense, then, for the US to continue to rely only on improved versions of existing launch vehicles would be to limp back into space. Its rocket fleet could meet current launch needs and allow limited growth in space activity. But the country would have to abandon dreams of advanced solar system exploration or more than basic space station operation - to say nothing of returning to the moon or deploying the star-wars system.

Yet, OTA observes, ``New space launch vehicles with dramatically increased capabilities and reduced costs are now technically possible.'' They include unmanned heavy lift rockets, one of which would be based on the shuttle, and a second-generation manned shuttle. If the US doesn't want to develop any of these now, it could build more resilience into its launch system by building more launch pads and rocket factories.

Any of these options would add one to several billion dollars to the annual space budget. Which one the next administration and Congress might choose would depend on what they want to do in space. The more ambitious the goals, the more rocket power is needed.

Since the glory days of the Apollo moon program, the US has tried to do too much in space with too few resources. If the next administration and Congress truly want to revitalize American space science, prepare for a strong manned spaceflight program in the late 1990s, and build advanced military space capability, they must substantially improve the launch system.

If they won't spend the money to do this, they should forget such ambitious goals. What they cannot do is avoid making this crucial decision, which the present administration and Congress have postponed.

A Tuesday column. Robert C. Cowen is the Monitor's natural science editor.