EDWARDS AIR FORCE BASE, CALIF., JUNE 7 -- Thunderstorms, lightning and erratic winds forced the Air Force today to put off a test firing of a Titan 34D rocket considered crucial to the resumption of U.S. military space launches.

Air Force Sgt. William Schwartz said that the earliest possible day for the test firing of the solid-fuel rocket is Tuesday, "but no way before then because of the weather."

Ignition of the 90-foot booster, mounted nose-up on a test stand for the two-minute firing, was initially scheduled for Wednesday.

But erratic winds on that day and Thursday, followed by rain and lightning on Friday and Saturday, forced delays until today, when the decision was made to postpone again, Schwartz said.

A successful test firing could mean that military space launches would resume in the next few months, officials said.

The Titan 34D, which develops 1.4 million pounds of thrust, is the premier launcher in the Air Force inventory. Other than the shuttle's giant boosters, the Titan is the largest solid-propellant booster in use in the world.

Back-to-back rocket failures in 1985 and last year grounded the Titan 34D program indefinitely. A booster failure six seconds after launch from Vandenberg Air Force Base on April 18, 1986, also resulted in the loss of a costly spy satellite.