It will be the fifth instalment of the Ariel Machine Learning Data Challenge, following four competitions in the past five years. The Ariel Data Challenge attracts around 200 participants from across the world every year, including entrants from leading academic institutes and AI companies. This challenge and its predecessor took a bite-sized aspect of a larger problem to help make exoplanet research more accessible to the machine learning community. The challenge is not designed to definitively solve the data analysis issues faced by the mission outright but provides a forum for discussion, and to encourage future collaborations, and to help the Ariel team to be prepared with the best possible data analysis methods by the time the mission flies.