Altair Lander Life Support: Design Analysis Cycles 4 and 5

Abstract

NASA is working to develop a new lunar lander to support lunar exploration. The development process that the Altair project is using for this vehicle is unlike most others. In "Lander Design Analysis Cycle 1" (LDAC-1), a single-string, minimum functionality design concept was developed, including life support systems for different vehicle configuration concepts, first for a combination of an ascent vehicle and a habitat with integral airlocks, and then for a combined ascent vehicle-habitat with a detachable airlock. In LDAC-2, the Altair team took the ascent vehicle-habitat with detachable airlock and analyzed the design for the components that were the largest contributors to the risk of loss of crew (LOC). For life support, the largest drivers were related to oxygen supply and carbon dioxide control. Integrated abort options were developed at the vehicle level. Many life support failures were not considered to result in LOC because they had a long enough time to effect that abort was considered a feasible option to safely end the mission before the situation became life threatening. These failures were then classified as loss of mission (LOM) failures. Many options to reduce LOC risk were considered, and mass efficient solutions to the LOC problems were added to the vehicle design at the end of LDAC-2. In LDAC-3, the new design was analyzed for large contributors to the risk of LOM. To avoid ending the mission early or being unable to accomplish goals like performing all planned extravehicular activities (EVAs), various options were assessed for their combination of risk reduction and mass cost. This paper outlines the major assumptions, design features, and decisions related to the development of the life support system for the Altair project through LDAC-3.

Update to Mars Ascent Vehicle Design for Human Exploration

“…The life support systems for the Mars Ascent Vehicle are based heavily on the Altair life support systems [13]. Some changes are made to the water system to include additional capability for purification due to the long duration of dormancy prior to crew access on the Martian surface.…”

Mars Ascent Vehicle Design for Human Exploration

“…Like the avionics system, the life support systems for the Mars Ascent Vehicle are based heavily on the Altair life support systems 10 . Some changes are made to the water system to include additional capability for purification due to the long duration of dormancy prior to crew access on the Martian surface.…”