NASA officials said they don't expect damage to a test booster will delay the tentatively scheduled September launch of the first space shuttle since the 1986 Challenger disaster. The accident will, however, postpone the final test-firing of Morton Thiokol's redesigned booster from July 25 until the end of August, officials said. The booster was damaged Saturday when a worker testing one of the motor's three field joints inadvertently switched pressurization lines and damaged insulation that helps contain superheated gases during flight.