The ADM was completely designed, built, tested and qualified for spaceflight by the EIRSAT-1 team. The four antenna elements form two dipole antennas, one for UHF downlink (signal from the satellite to the ground station) and one dipole antenna for VHF uplink (signal from the ground station to the satellite). The coarse sun sensor is used for attitude determination.

 

The antenna deployment system is one of the most vital subsystems on-board. The door opening mechanisms and antenna deployment mechanisms have therefore been tested extensively.

 

How does it work? Each door is held closed by two melt lines (dyneema lines normally used for fishing) which go over and under two resistors. When a current is applied to the resistors, the line melts and breaks. A spring then releases the door, and the antenna deploys - like a tape measure!