A Mission Alpha is a dry run for the year's Main Mission.
Missions Alpha were typically run about 1 month before the actual mission, lasting about 4–6 hours in duration. The purpose was to test out all equipment, and discover any problems or areas lacking proper planning. It also was an excellent opportunity to test the level of training for both Astronauts and Mission Control staff. This practice was first started by Mission Commanders Daniel Kekez and Jamie Rosen for the Jupiter 1998 mission.
List of Missions Alpha