This study explored the impact of an extended explicit-reflective instruction through a triple blended learning environment (triple-BLE) on pre-service science teachers' (PSTs) views of the nature of science (NOS). The triple-BLE included face-to-face (F2F), online, and out-of-school time (OST) engagement over two semesters. The study employed a pre-, mid-, and post-test design with random assignment. Seventy PSTs (33 males, 37 females) were randomly assigned to the treatment (N = 34) and control group (N = 36). While F2F and OST learning environments were common for both groups, the treatment group experienced a triple-BLE which integrated online learning into F2F and OST learning environments. Online learning environment used in this study consists of four main and 12 sub-components. The PSTs' NOS views were assessed with the "Views of The Nature of Science--Form C" questionnaire and follow-up individual semi-structured interviews. The results indicated that most PSTs in both groups initially held naïve views about all aspects of NOS. Mid-way, both groups made some positive changes compared to pre-tests, with a slight advantage for the treatment group. At the end of the intervention, the treatment group achieved noticeably more substantial gains in their NOS understanding compared to the control group. The study provides empirical support for the effectiveness of online learning in augmenting and enhancing the impact of F2F and OST experiences in promoting preservice teachers' understanding of NOS.