Letting engineers speak out. SAFETY

MOST engineers agree that the redesigned space shuttle is, on the whole, a safer spacecraft. The lingering question, however, is whether or not the ``new'' NASA and its contractors are safer too. The Discovery launch that's coming up may be the most cautiously executed in shuttle history. But the true test of how deeply the agency has reexamined its commitment to safety will be the rigorous launch schedule it has set for itself for the next few years.

NASA has made several organizational changes in response to the report of the Presidential Commission on the Space Shuttle Challenger Accident (the Rogers Commission) and other studies flowing from it.

The agency created an office for safety, reliability, maintainability, and quality assurance, the manager of which reports directly to the NASA administrator.

It also contracted Battelle, a consulting firm, to set up a system of confidential reporting that allows engineers, managers, and other NASA employees or contractors to voice safety concerns about the shuttle without fear of penalty. Battelle passes anonymous summaries of the reports to NASA headquarters to supplement other safety reporting.

A ``substantial number'' of reports have come in, says Michael Hanley, Battelle project manager. He declined to be more specific.

Roger Boisjoly, on the other hand, says that most of the changes at NASA and its contractors since the Challenger accident are cosmetic. Mr. Boisjoly is a former Morton Thiokol aerospace engineer who worked on the rocket-booster O-rings that caused the 1986 Challenger accident. The night before the disaster, Boisjoly advised Morton Thiokol managers not to launch because previous missions and tests had shown serious O-ring damage. His concerns were overridden.

``You can have the best program design in the world and if you have not instilled the confidence in the employees that they will not get punished for speaking out, then the best-designed program will not work,'' he says. ``And that is exactly what you have at the present time.''

Others see more-hopeful signs.

``Right after the accident, and for sometime thereafter, the tensions were high in all the organizations that had anything to do with the shuttle, and particularly the solid rocket motor,'' says Guyford Stever, chairman of a special committee to oversee the redesign of the boosters.

As the redesign process went forward, ``there were a large number of voices raised on many issues and we had what I consider good honest arguments - sometimes knock-down, drag-'em-out,'' Dr. Stever says. ``People realized that everybody's contribution was valuable. Not too much was hidden.''

Changes in shuttle hardware have probably decreased the known risks of flight, but may have increased the unknown risks, risk analysts say. Yet a post-Challenger report evaluating risk management for the shuttle ``got very little feedback from NASA,'' says David Johnson, director of the National Research Council study.

NASA seems ``unhappy about doing anything in the way of quantitative risk assessment,'' he says.