A Century of Progress (balloon) - In preparation

Active Chemical Ionization Mass Spectrometer (ACIMS) - In preparation

Advanced Thin Ionization Calorimeter (ATIC) - In preparation

Aeroclipper (Tethered marine balloon) - In preparation

Aeromedical Field Laboratory (AMFL) - In preparation

Aeronautics and Cosmonautics Romanian Association (ARCA)

Aeronomy

Aerostar International

Air Force Cambridge Research Laboratory (AFCRL) - In preparation

Airship - In preparation

AKERMAN, John D. (1897 - 1972)

ALICE (A Large Isotopic Composition Experiment) - In preparation

ALIR (Infrared Telescope) - In preparation

ALVAREZ, Luis W. (1911 - 1988) - In preparation

AMETHYSTE Campaign (1994) - In preparation

Anchor Line - In preparation

ANDERSON, Orville A. (1895 - 1965) - In preparation

ANDREEV, Evgeny N. (1926 - 2000)

Animals as test subject in balloon missions - In preparation

Antarctic Impulse Transient Array (ANITA) - In preparation

Anti-Electron Sub Orbital Payload (AESOP) - In preparation

Antropomorphic Dummies - In preparation

Apollo XIX (Balloon mission) - In preparation

ARCADE (Absolute Radiometer for Cosmology, Astrophysics, and Diffuse Emission) - In preparation

Archimedes principle - In preparation

ARD (Atmospheric Reentry Demonstrator) - In preparation

ARGENTINE - Balloon program - In preparation

ARGOS (System)

ASHCAN (Program) - In preparation

Astrofilm - In preparation

ATA Aerospace - In preparation

Atmosphere

Atmospheric Balloon Lidar Experiment (ABLE) - In preparation

AUSTRALIA - Balloon program - In preparation

Auxiliary balloon - In preparation