A Minimal Architecture for Human Journeys to Mars

Proposed architectures for human journeys to Mars need to take note of the two competing constraints of an executable program: the annual NASA human spaceflight budget will likely remain constrained (possibly growing with inflation), and going to Mars and landing on Mars need to happen within the interest horizon of the various stakeholders, including the public. In this article we describe a stepwise approach for human journeys to Mars using a minimal architecture. We refer to this architecture as minimal because it would minimize large new development efforts and rely largely on elements currently being developed or planned by NASA, such as SLS, Orion, a deep space habitat, and a 100-kWe-class SEP tug. In the architecture proposed here, human missions to Mars would begin with a crewed landing on Phobos in 2033, followed by a short-stay landing on Mars in 2039, and continue with a one-year stay in 2043. Each mission campaign would build on previous campaigns, leaving a legacy and new capabilities for those that follow. A first look independent cost assessment by the Aerospace Corporation suggests that this example could plausibly fit within an inflation-adjusted budget. Furthermore, although not considered here, international contributions could offset some of the cost.