India's human spaceflight ambitions received a significant boost with the Axiom Mission 4 (Ax-4), which saw Group Captain Shubhanshu Shukla become the first Indian astronaut to reside on the International Space Station (ISS). Launched on June 25, 2025, aboard a SpaceX Crew Dragon, Shukla's ~18-day mission was not just a symbolic moment but a crucial step in preparing for the Gaganyaan mission, slated for early 2027.
During his stay, Shukla conducted around 60 experiments, including seven vital studies designed by ISRO and Indian institutions. These experiments delved into the effects of microgravity on muscle health, the growth of microalgae, cognitive behavior, and the resilience of crops—areas critical for future long-duration spaceflights.
ISRO emphasized the invaluable hands-on experience gained through Ax-4. The mission provided critical insights into astronaut training protocols, health monitoring in space, crew coordination, the execution of scientific experiments under real space conditions, and emergency response procedures. According to ISRO, these learnings are directly applicable and essential for the success of the upcoming Gaganyaan mission, India's first crewed orbital mission.
While the mission involved a considerable investment for ISRO, estimated between ₹230 crore and ₹548 crore for training, logistics, and operations, the knowledge and experience acquired are considered paramount. The mission also highlighted international collaboration in space, overcoming a temporary postponement due to an air leak in the Russian segment of the ISS before launching successfully with an international crew.
Group Captain Shukla aptly described the mission as "India's second orbit," signifying India's transition towards a leadership role in human spaceflight. The data and insights garnered from Ax-4 are expected to significantly refine astronaut readiness, enhance ground support coordination, validate safety measures, and optimize operational protocols for the Gaganyaan program, bringing India closer to realizing its independent human spaceflight capabilities.