Glossary

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AAS Advanced Automated System (program) (FAA)

ACDA Arms Control and Disarmament Agency

ACO Advanced Concepts Office (NASA)

ACTS Advanced Communications Technology Satellite

ADEOS (Japanese) Advanced Earth Observing Satellite

AEB Brazilian space agency

ADS-B Automatic Dependent Surveillance-Broadcast

AGO Automatic Geophysical Observatory

AIDS Acquired Immune Deficiency Syndrome

AMOS Air Force Maui Optical System

anechoic Neither having nor producing an echo angle of attack. The acute angle of attack between the chord of an airfoil and its direction of motion relative to the air, often referred to as "alpha"; when an airfoil's exceeds the one that provides maximum lift, it goes into a stall, losing air speed and, potentially, the capability of the pilot to control the airplane.

ARC Ames Research Center (NASA)

ARPA Advanced Research Projects Agency (formerly Defense Advanced Research Project Agency)

ARS Agricultural Research Service (USDA)

ASRM Advanced Solid Rocket Motor

ASTP Apollo-Soyuz Test Project

Astro Astronomy Observatory

astronomical unit A measure for distances in space, equal to the mean distance of the Earth from the Sun-that is, 93,000,000 miles (149,599,000 kilometers)

ATLAS Atmospheric Laboratory for Applications and Science

ATV Automated Transfer Vehicle

AVHRR Advanced Very High Resolution Radiometer

AVIRIS Airborne Visible and Infrared Imaging Spectrometer

AXAF Advanced X-ray Astrophysics Facility