The ceremony of the Opening of the Holy Door, celebrated by Pope Francis at the Vatican on 8 December 2015, has been the largest event produced exclusively in UltraHD 4k and distributed worldwide live via satellite in UltraHD 4k and HD. This paper describes the challenges faced by CTV (Centro Televisivo Vaticano) and its partners in the implementation of the UltraHD 4k production and distribution of the event to the entire world. Several decisions and choices had to be made in the design of the technical infrastructure, while seeking to maximize the reach of the signal, ensure the most reliable transmission, and bring into play a technology that was not entirely mature at the time of the event.