Advanced Life Support Advanced Launch System Active Line State Advanced Light Source Approach Lighting System Advanced Logistics System advanced low-power Schottky Alternate Landing Site Alton and Southern Railway American Littoral Society amyotrophic lateral sclerosis Application Layer Structure Approach Light System Automated Library System Automatic Landing System acid-labile subunit Ada Language System Adjacent Link Station Airman Leadership School Alternate Launch Site alternating least squares Approach Landing System Approach Light Systems Archimedial Log Spiral Automatic Laser Shutdown autonomous listening station accident localization system acetolactate synthase acid-labile surfactant acute leukemias