"ALT-10" . . . . "ALT-11" . "'''ALT-12'''" . "drop tests" . "'''ALT-15'''" . . "free flight" . "'''ALT-13'''" . "'''ALT-16'''" . "'''ALT-14'''" . . "ALT" . . "atmospheric flight tests" . "ALT-12" . "initial atmospheric landing tests (ALT)" . "atmospheric testing" . "ALT-13" . "ALT-16" . . "ALT-14" . "ALT-9" . "ALT-15" . "Space Shuttle Approach and Landing Test Flights" . "Approach and Landing Test" . "Approach and Landing Tests" . "ALT free flights" . "Approach and Landing Tests" . "ALT program" . "Approach and Landing validation testing" . . "ALT Free Flight#1" .