Columbia's flight: some firsts for No. 3

Even though America's reusable space shuttle Columbia is poised to make its third flight into space, the event should be another significant first.

At this writing, the spacecraft was standing by for liftoff from Launch Complex 39A at Cape Canaveral. If astronauts Jack R. Lousma and Clark Gordon Fullerton make it into orbit, this will, of course, be the first time a used ship has made a third trip into space.

That is not a trivial statement, as National Aeronautics and Space Administration (NASA) officials here have repeatedly point out. Successful completion of this seven-day mission would be a major step toward qualifying the shuttle as an operational Space Transportation System (STS), as it is called officially.

However, there are other ''firsts'' scheduled for this mission which illustate the versatility of the STS concept.

There are, for instance, Todd Nelson's moths and honey bees. They will be showing how insects maintain flight stability and orientation when weightless.

This experiment, which led the crew to take along a bee swatter for security, is the forerunner of many student experiments. Todd E. Nelson, a high school senior at the Southland Public School in Adams, Minnesota, is one of the finalists of NASA's first Space Shuttle Student Involvement Projects. Together with industrial sponsors - in this case, Honeywell, Inc. - NASA provides guidance and support for student experiments that can be put into lockers on the spacecraft.

Columbia will also be carrying the ''getaway special'' container to test its space worthiness. This is a small container in which, for modest fee, anyone can fly self-contained experiments which require no astronaut supervision. NASA already has something like 320 reservations for its Small Self-Contained Payloads program, to use its official name. They have been made by 191 individuals and groups from 33 states plus the District of Columbia, plus 14 foreign nations. Customers include the Japanese newspaper Asahi Shimbun, which plans an experiment on snow crystalization under weightless conditions. The experiment was suggested by Japanese high school students.

Thus it is that the space shuttle - which will carry out secret military missions, launch such major scientific instruments as the Space Telescope and carry multi-million dollar commerical payloads - also has room for the projects of ordinary people, even of schoolchildren.

For scientists with experiments to orbit, this mission of Columbia should demonstrate yet another kind of breakthrough - the opportunity for a second chance. Space scientists have sometimes seen years of preparation go to waste when equipment or even the space vehicle itself failed. Accomodation for experiments on the shuttle is at a premium and is booked well in advance. Nevertheless, if an experiment fails, there can be an opportunity to fly it again as future shuttle flights become routine.

Botanists Allen H. Brown of the University of Pennsylvania and David K. Chapman of the University City Science Center in Philadelphia are benefitting from the first such opportunity. Their experiment with weightless growth of dwarf sunflowers [Helianthus annuus] came to naught when the second shuttle flight was cut short last November. There wasn't time enough for the plants to achieve significant growth when that planned five-day mission ended after only 54 hours in orbit because of a fuel cell failure. Now the experimenters not only have a second chance, but the prospect of an even longer time in space than they had originally expected.

This capability to fly an experiment again adds a new dimension to space research. Not only will there be opportunities to recover from failure, but scientists can carry out series of experiments over an extended time. Each new phase can serve as a follow-up of what is learned on earlier shuttle flights.

The primary purpose of this third shuttle mission is to continue flight testing. Columbia will be pushed closer to its operational limits. Its capacity to deal with heat loads will be tested as it orbits for extended periods with its tail or nose pointed at the sun, or with full sunshine bathing its open equipment bay. The movable arm supplied by Canada will be exercised more rigorously. Maneuvering rockets will be fired up after having thoroughly cooled down to see how well they perform what's called a ''cold start.'' And Columbia will be put through more strenuous aerodynamic maneuvers than have so far been attempted on reentry.

But while such flight tests are the prime focus of the mission, it is the moths and the honey bees and the dwarf sunflowers that illustrate the wide ranging potential which the shuttle has for opening up a new space flight era.