The U.S. Court of Military Appeals has rejected an effort to block the court-martial of Air Force 2nd Lt. Christopher M. Cooke, clearing the way for his military trial next week on charges he passed Titan missile secrets to the Soviet Union.

In a 2-to-1 decision, the court dismissed Cooke's claim that the Air Force broke a promise that it would forgo prosecution if he confessed and passed a lie detector test on what he had given the Soviets.

Cooke, 25, of Richmond, has been in custody since Air Force investigators followed him to the Soviet Embassy in Washington May 2. In recently filed court papers, the Air Force said Cooke had confessed that for a year he had been "photographing, copying and giving the Soviets" secrets about the American nuclear arsenal. He passed a lie detector test on those incriminating statements, the court papers said.

His court-martial is to begin Monday at Andrews Air Force Base, Md.

The Justice Department also has been reviewing the evidence against Cooke. But officials there have said privately that criminal espionage charges are doubtful because of the immunity controversy and because the Air Force refused for days to let the lieutenant talk to an attorney.

In the decision filed late Monday, Judge William H. Cook said subordinate Air Force officers had no legal authority to grant Cooke immunity, and the only legal consequence of their promise to do so would be to render his statements inadmissible as evidence.