Congress waited to investigate the Challenger accident until the Rogers commission reported. But there doesn't seem to be much left to say. Before the accident, Congress mostly led cheers. Now the tone is suddenly sterner. James Scheuer, a senior Democrat on the House Science and Technology Committee, complains about "this cult of arrogance" that grew up in NASA. Others, including the senior Democrat on the Senate Commerce, Science and Transportation Committee, Ernest Hollings, wonder aloud about possible criminal prosecution of some NASA officials, especially Lawrence Mulloy, former head of the solid-fuel booster rocket program at Marshall Space Flight Center.

Mr. Mulloy served no one well in this affair. The Challenger was brought down by a leaking O-ring in one of the booster assemblies. He knew of the tendency of such rings to leak, was warned that the cold weather the night before the launch would exacerbate that tendency, overrode the warnings, failed to pass them along to superiors and thereby let the launch go on. Then he gave some suspect testimony about these events to the commission.

The commission carefully noted all this, but took note as well of the system within which Mr. Mulloy was operating. There was enormous pressure inside NASA to step up and maintain the frequency of flights. Without ever quite saying so, the commission left the distinct impression that in steamrollering the obstacles to flight, Mr. Mulloy was doing just what his superiors -- the system -- wanted him to, and that inside NASA there were few rewards for an official who might counsel caution.

Sen. Hollings summarized it neatly. "You and I differ," he said to panel chairman William Rogers. "You say the process was flawed. I find the process and safety procedures violated. If we let them know down at NASA that they are going to be held responsible, then we'll have a fine safe program that we all want to continue." Of course Mr. Mulloy was not "trying to kill astronauts," the senator said; nevertheless he was guilty of "willful gross negligence."

But, as Mr. Rogers replied, that's too easy. While "it's not beyond the realm of possibility that some ambitious prosecutor might try," said the former attorney general, he doubted a prosecution would succeed. He also doubted that it should: "I'm not sure picking out any scapegoat and prosecuting would serve the national interest."

In this country, we mostly flail our bureaucracies because they are averse to risk; they duck too much. Any public action is risky; space flight, for all the obvious reasons, is riskier. Mr. Mulloy and the others involved made a series of horrible mistakes. They and everyone else now know that. But they are not criminals. A balancing is required now, and the courts are the wrong place to achieve it.