Appropriations and expenditures Aeronautics Safety measures Outer space Exploration Government policy Volcanic ash, tuff, etc Volcanic hazard analysis Aeronautics Safety measures Finance Aeronautics and state Aeronautics, Commercial Aeronautics, Commercial Research Finance Air traffic control Artificial satellites in earth sciences Asteroids Collisions with Earth Asteroids Speed Modification Astronautics Astronautics Finance Astronautics and state Astronautics in earth sciences Astronauts Health and hygiene Astronauts Medical care Evaluation Climatic changes Detection Comets Collisions with Earth Earth sciences Remote sensing Earth sciences and state Forest management Remote sensing Management Manned space flight Government policy National Airspace System (U.S.) National security Remote sensing Natural resources Management Remote sensing Near-earth asteroids