All-solid-state lithium-ion batteries (ASSBs) have a wide operating temperature range (−40 °C to +120 °C) and are expected to be applied to lunar exploration, which has become increasingly active in recent years. Since a ground development test confirmed that ASSBs are tolerant of the space environment, in this study, a space demonstration test is conducted on the International Space Station (ISS). The battery was exposed in the ISS Exposed Section for 434 days. A total of 562 charge–discharge cycle tests were conducted, in addition to basic charge–discharge characterization, with no significant degradation observed in the charge–discharge characteristics or battery appearance. These results confirm that the battery operates reliably even in a complex space environment. This test confirmed that the lifetime characteristics of ASSBs can be estimated via ground-based charge–discharge characteristics, encouraging their potential application in space exploration.

The growing accessibility of small satellite technologies and international cooperation frameworks has enabled many emerging countries to initiate space development activities; however, the mechanisms through which they build and advance satellite development capabilities remain insufficiently theorized, as existing models such as the Space Technology Ladder capture only high-level milestones. To address this gap, this study proposes the Satellite Technology Ladder (SaTL), a structured 16-level framework integrating satellite development methods and satellite size as indicators of technological maturity. We conducted a comprehensive longitudinal analysis of all satellite projects initiated since 1990 across 16 emerging countries, coding each project according to the SaTL scheme and evaluating national trajectories over time. The analysis reveals four distinct developmental trajectories: (1) prolonged dependence on foreign procurement, (2) gradual capability enhancement through externally supported development, (3) expansion of domestic industrial ecosystems following initial collaboration, and (4) independent development from the outset based on pre-existing technological foundations. These findings demonstrate that technological advancement depends not only on technology introduction but also on absorptive capacity, institutional learning, and broader industrial structures. SaTL thus offers a theoretically grounded and empirically validated tool for assessing capability formation and informing policy strategies in emerging spacefaring nations.