Nira Schwartz, a former senior engineer at TRW Inc.'s Space Group in Redondo Beach, Calif., said the company had knowingly and falsely misrepresented the performance of its discrimination algorithm for an antimissile system. In 1996, Schwartz filed a $500 million suit on behalf of the government against TRW under the False Claims Act.

Schwartz claims that she was fired when she pressed the company to tell the military and its industrial partners that the software failed to distinguish decoys from real warheads 90 percent of the time.

In an official statement, TRW denied that it had "improperly manipulated" the flight test data and cited its successful review by two independent panels. A spokesman for the US Department of Defense noted that the government has not joined the suit.