Technology roadmap for future human landing systems

We describe a model-based technology roadmap that explores the capability of human landing systems to deliver crew to and from the lunar surface for short-stay ‘sortie’ missions. This kind of mission is assumed to take place through the first five years of future human lunar exploration and during the following early stage of the lunar outpost initial operational capability. After that, the human landing system will be able to continue transporting people to and from the Moon but will need to undergo some modifications to be able to stay dormant at the outpost for longer periods of time, up to 180 days. In this paper we describe the technology roadmapping approach that has been adopted. We use an Object Process Model to describe the lunar human landing system and supporting infrastructure. We define relevant figures of merit to measure performance and cost associated with lunar landing system developments. We provide a benchmark of the state of the art in lunar landing systems through a comprehensive literature review, and describe a technical model to set credible performance targets for future landing systems. In our analysis, we adopt NASA as the reference customer. We assume a landing crew of 4 people, operating on the lunar surface for 7 days. We assume departure and return points as the Lunar Gateway station in near rectilinear halo orbit. We assume a payload mass delivered to the surface of 500 kg, with additional 250 kg allowance. Based on a tradespace modeling exercise, we explored alternative system architectures for lunar landing systems. The analysis allowed us to set targets for future development, which we organized in a technology roadmap timeline. The roadmap suggests an informed path forward for future development of lunar landing systems, setting credible technology targets that are validated by the described model-based approach. All suggestions in the roadmap are backed up by technical models, which are briefly overviewed in the paper.