Due to the lack of matched dedicated small satellite launch vehicles, launch opportunities as a rideshare or piggyback using a highly reliable launch system has become increasingly important for small satellite developers. The objective of this paper is to provide an aggregated value method as a strategy for developers to evaluate launch opportunities, as well as an approach for the launchers to capture the market dynamics. Based on an up-to-date launch record, a reliable launch database for multi-attribute evaluation is established. Efforts are made to quantify the abstract and concrete attributes of launch systems. An aggregated preference value model is developed, translating different inherited capabilities of launch systems into integrated preference value as a reference for decision-making. The preference values of the launch opportunities of different launch vehicles are explored in a case study by the method proposed, and its feasibility and applicability for small satellite launch system evaluation tasks is validated.