The shuttle is for sharing

Congratulations, Columbia! Making it back into orbit a third time after a near flawless countdown is another big step toward the goal of an operational Space Transportation System.

Astronauts Jack Lousma and Gordon Fullerton are to be commended for their skillful performance. They will understand, however, if the nation's admiration includes one Todd Nelson. As the first high-school science student to fly an experiment on the shuttle, he is opening a new era of space exploration - an era of wider opportunity for interested people to share in one of the great adventures of the age. The so-called ''getaway specials'' -- shuttle canisters in which small experiments can be carried cheaply -- extend this opportunity beyond the subsidized student participation program.

Certainly the shuttle concept brings important new dimensions to space flight. President Reagan is wise to maintain strong support for the shuttle program at a time of severe budget cutbacks. It is reasonable to trim other parts of the space budget to hold down overall costs. It is not reasonable to shut down operating spacecraft which still are returning valuable data just to save a few million dollars.

Provision in the fiscal 1983 budget to turn off the spacecraft now orbiting Venus and Pioneers 10 and 11, which are entering unexplored regions of the outer solar system, seems especially misguided. Many hundreds of millions of tax dollars have been spent putting those spacecraft in position. To throw away an important part of the return on that investment is questionable fiscal management, to say nothing of depriving the country and humanity of new scientific knowledge which otherwise would be gained.

Thus it is that enthusiasm for Columbia's third mission has to be tempered with misgivings about the overall thrust of the US administration's space policy.