With one eye trained on the maneuvers of space shuttle Columbia, US space planners are already looking ahead to the next phase of space flight.
Their vision, which they expect will begin to be realized later in this decade, encompasses a variety of permanent platforms in space. Some of these would be bases for automated or ground-controlled instruments. Others would be permanently manned space stations.
Columbia, which could be one of the shuttles that would help build such platforms, was continuing a largely successful third flight test at this writing. Minor malfunctions, including the frustrating loss of some of the TV cameras, have forced some changes or deletions of planned tests and some rearrangement of astronaut chores. Nevertheless, mission controllers here say they are generally pleased with the way the mission has unfolded so far. Astronauts Jack Lousma and Gordon Fullerton already have accomplished a great deal of important work on what has become the longest shuttle mission to date, the controllers say.
Among other tests, the astronauts have begun to exercise the spacecraft's mechanical arm. Like the shuttle itself, this Canadian-supplied limb symbolizes the future that planners for the National Aeronautics and Space Administration (NASA) envision. It or its successors would be a major tool used both for building space platforms and for placing and retrieving instruments the platforms would carry.
Presidential science adviser George Keyworth, in talking publicly about administration space policy, has said a number of times that the reusable shuttle is the cornerstone on which that policy is being built. This includes using the shuttle's capabilities to build the next generation of space facilities. NASA administrator James M. Beggs says he believes space platforms are the logical next phase.
Various concepts for such platforms - both manned and unmanned - are being developed by NASA and by industrial contractors. Some of these concepts are outlined in material that the Marshall Space Flight Center at Huntsville, Ala., has made available here during the current shuttle mission.
As a platform for scientific observations, the shuttle has two major limitations. To point instruments mounted in the equipment bay, the entire shuttle must be oriented. This means, for example, that studies of Earth and of objects in deep space cannot be made simultaneously. Also, shuttle missions are limited to no more than nine days mainly because fuel cell power supply would run out of fuel.
A solar-powered platform permanently in orbit, which could hold telescopes and other instruments carried up by the shuttle, would overcome both limitations. Marshall planners note that such a platform, which they hope to place in low Earth orbit by 1987, could generate far more power than the shuttle can supply. Moreover, its solar panels - 13 feet wide by 120 feet long - would generate power for an indefinite length of time. Instruments, such as different kinds of telescopes, could operate independently, pointing wherever their managers like.
As now envisioned, such a platform would evolve into larger units that could accommodate more instruments. They could even become the nucleus of a manned space station. As an intermediate step toward this latter goal, the European-supplied Spacelab could be docked with such a platform. This laboratory , to be mounted in the shuttle bay, provides a shirt-sleeve working environment.
Meanwhile, here at the Johnson Space Center, other planners are looking at space stations from a different perspective. They have developed a concept for a Space Operations Center - a manned station that would serve as a base and a command center for orbital operations. Built from modular units carried up by the shuttle, it would house an 8-to 12-person crew in a facility 435 feet long.
Out of all this long-range planning, a new space strategy for the United States is likely to emerge during the next few years. The thinking so far already has generated a major policy issue. Should a manned station be a joint military and civilian facility or should there be separate stations, one for each purpose? And if there is to be a totally civilian station, should the US invite Western Europe and Japan to help build and use it as a joint facility?
NASA administrator Beggs has been championing the latter concept while his deputy, Dr. Hans Mark, is promoting military uses. Right now, US national and world attention focuses on Columbia. But within the administration a new space program, based on the shuttle but going far beyond it, is being forged.