The correct option is that only two of the mentioned space missions support micro-gravity research. Axiom-4, part of the Axiom Space program, aims to facilitate commercial missions to the International Space Station (ISS), where micro-gravity research is a fundamental focus. Similarly, SpaDeX, which is designed for scientific and research purposes, also promotes experiments in micro-gravity environments. In contrast, Gaganyaan, India's human spaceflight program, while significant for various space exploration objectives, does not primarily target micro-gravity research in its initial phases. This distinction is crucial for understanding the broader implications of space missions on scientific research, as emphasized in UPSC preparatory sources.