The VR-MARS project represents a support system for urgent healthcare delivery in isolated environments, based on virtual reality and embodied conversational agents (ECA). We hypothesize that these two technologies enable better situational awareness and care coordination between 3 parties: a care provider in an isolated location, a critically ill patient and the control centre on Earth. VR-MARS explore the scientific fields of emergency medicine, human factors and virtual reality. The use case of VR-MARS will be related to space medicine, in particular emergency care during a manned spaceflight to Mars. During these missions, temporal isolation will add to physical isolation, because of delays in communication between the care provider (on Mars) and ground control (on Earth), which will preclude real-time telemedical support. VR-MARS will be built around two simultaneous decision loops which will allow task assignment and synchronisation between the care provider, the ECA and ground control. The ECA will interact with the care provider via augmented reality. Upon request, it will deliver step-by-step guidance on medical protocols, using reassuring verbal tone and cues in order to mitigate the stress of the care providers. As soon as it is available, ground control on Earth will be made aware of the situation on Mars and of the procedures being undertaken by the care provider. This will improve situational awareness on the ground and enable the most optimal decision making in the mid- to long-term. In return, ground control will deliver its recommendation to the care provider via the ECA. Therefore, the ECA will represent the central hub of communication between the two sites. VR-MARS will be tested on two medical scenarios involving a critically ill patient represented by a high-fidelity simulator. Technical and non-technical skills of the care provider will be assessed at two levels: immediate interactions between the care provider and the ECA (for urgent, life-saving decisions) and delayed interactions between the care provider and ground control (for mid- and long-term decisions). With regards to research output and spinoffs, we anticipate that VR-MARS will improve medical care in remote environments, such as humanitarian missions, the combat environment, medical evacuations, expedition medicine, etc.