Evaluating the Strategic and Economic Viability of Gateway for Human Space Exploration

More than 54 years after humans last set foot on the Moon, astronauts are poised to return through NASA’s Artemis program. These missions aim to pave the way for sustained human presence on the lunar surface and to deploy the Lunar Gateway, an orbital outpost designed to support exploration beyond low Earth orbit. While Gateway offers promising opportunities to modularize and expand lunar transfer architectures, its substantial price raises ongoing debates surrounding its cost-effectiveness. This paper evaluates the economic and strategic utility of the Lunar Gateway by comparing three lunar mission architectures currently under development. These include: an Artemis III-like architecture using Orion and the Starship Human Landing System to transport crew via a near-rectilinear halo orbit; a Gateway-based architecture with Blue Origin's Blue Moon Mk2 leveraging the outpost as a staging and logistics hub; and a monolithic architecture relying on direct Earth-to-Moon transit using Starship. Each architecture is assessed under the early stages of lunar exploration, assuming a crew of four astronauts supported solely by Earth-supplied resources. In addition to evaluating economic performance, the study examines the maximum surface mission duration enabled by each approach. This analysis is complemented by qualitative discussions on key architectural considerations, including the alignment with international collaboration objectives, the opportunity to foster the development of a cislunar economy, and the scalability toward future Mars missions. Given the dynamic nature of spacecraft development, the paper incorporates informed assumptions and conducts sensitivity analyses on key parameters such as vehicle performance and price. Based on current estimates, the study concludes that a direct landing architecture enabled by Starship outperforms a Gateway-enabled architecture by two orders of magnitude on a per kilogram basis. In terms of enabled exploration capabilities, the Starship lander also allows for mission durations almost four times greater than Blue Origin's Blue Moon Mk2. Nonetheless, Gateway is identified as an essential node for early lunar transfer architectures, fostering a cislunar economy and promoting international cooperation before larger vehicles are validated. Ultimately, the study offers a nuanced comparison of current lunar architectures, emphasizing that long-term strategic value may outweigh initial cost advantages in shaping a sustainable and scalable human presence beyond Earth. To further support architectural trade studies, the methodology is intentionally designed for adaptability, offering a flexible decision-making framework that remains applicable under evolving technical capabilities and economic conditions.