Quantum Key Distribution utilises fundamental quantum properties and mechanics to generate a cryptographic key, ensuring the highest security regardless of advances to computer processing. AMMEQ-1 is a 3U cubesat being developed by The University of Sydney, Australia hosting a primary payload provided by Centre for Quantum Technologies, Singapore. Its main purpose is to show USYD's capability of developing a satellite using COTS products and to demonstrate various technologies to support future QKD missions. This study describes the mission and overall system design of the cubesat.