Viagenie Deep space communications involve long delays (e.g., Earth to Mars is 4-20 minutes) and intermittent communications, because of orbital dynamics. In this context, typical QUIC stacks default transport parameters for terrestrial Internet are not suitable for deep space. This document defines a QUIC profile for deep space. It provides guidance on how to estimate and set transport parameters, advice to space mission operators and application developers on how to configure QUIC for the deep space use case and guidance to QUIC stack developers to properly expose the required transport parameters in their API.