Mars surface tunnel element concept

Abstract

When the first human visitors on Mars prepare to return to Earth, they will have to comply with stringent planetary protection requirements. Apollo Program experience warns that opening an EVA hatch directly to the surface will bring dust into the ascent vehicle. To prevent inadvertent return of potential Martian contaminants to Earth, careful consideration must be given to the way in which crew ingress their Mars Ascent Vehicle (MAV). For architectures involving more than one surface elementsuch as an ascent vehicle and a pressurized rover or surface habitat-a retractable tunnel that eliminates extravehicular activity (EVA) ingress is an attractive solution. Beyond addressing the immediate MAV access issue, a reusable tunnel may be useful for other surface applications, such as rover to habitat transfer, once its primary mission is complete. A National Aeronautics and Space Administration (NASA) team is studying the optimal balance between surface tunnel functionality, mass, and stowed volume as part of the Evolvable Mars Campaign (EMC). The study team began by identifying the minimum set of functional requirements needed for the tunnel to perform its primary mission, as this would presumably be the simplest design, with the lowest mass and volume. This Minimum Functional Tunnel then becomes a baseline against which various tunnel design concepts and potential alternatives can be traded, and aids in assessing the mass penalty of increased functionality. Preliminary analysis indicates that the mass of a single-mission tunnel is about 237 kg, not including mass growth allowance.

Update to Mars Ascent Vehicle Design for Human Exploration

“…They will install an inflatable tunnel between the MAV surface access hatch and the pressurized rover that will allow them to leave their Mars Extravehicular Activity (EVA) suits behind in the rover, and ingress the MAV in lightweight and clean Intravehicular Activity (IVA) suits. See figure 8 and reference [11] for crew access tunnel concepts. This approach is designed to eliminate contamination of the MAV with Martian dust and regolith for planetary protection reasons.…”

Human Mars ascent vehicle configuration and performance sensitivities

“…Configuration choices are driven by the need to minimize the height of the overall lander center of gravity for entry descent and landing and the desire to simplify crew access. Current designs assume crew access via pressurized tunnel from a rover [3]. (Figure 5).…”