By The Sampadak Express
The Indian Space Research Organisation (ISRO) has successfully reached a new milestone in its Space Docking Experiment (SpaDeX) mission, completing the “rolling” or “rotating” test. This groundbreaking experiment involved one satellite orbiting another and returning to its original position, all while maintaining line-of-sight visibility.
The test, which was completed last week, was confirmed by ISRO Chairman V. Narayanan in an interview with The Times of India. Narayanan emphasized the importance of conducting ground simulations to minimize errors and optimize data collection during such critical tests.
The rolling experiment is being compared to Chandrayaan-3’s “hop” test on the Moon, as both are considered significant advancements for future space missions. It demonstrates ISRO’s capability to control satellite movements from Earth, utilizing advanced software, sensors, and positioning technologies. This skillset is vital for upcoming missions like Chandrayaan-4, India’s human spaceflight program under Gaganyaan, and satellite servicing projects.
SpaDeX consists of two satellites: SDX01 (Chaser) and SDX02 (Target), which were launched together on December 30, 2024. The mission’s goal is to demonstrate orbital rendezvous, docking, and proximity operations—key technologies for future space exploration.
Earlier this year, in January 2025, ISRO became the fourth country in the world to achieve successful space docking using indigenous technology. With ample propellant still remaining in the satellites, ISRO plans to conduct additional experiments, further refining docking techniques in different orientations, including vertical docking scenarios. These experiments are expected to enhance understanding of how to position objects for docking under various conditions.
This achievement is a major step forward for India’s space exploration ambitions, paving the way for lunar sample return missions and the establishment of the Bharatiya Antariksh Station (Indian Space Station). The SpaDeX mission remains a crucial platform for testing and validating the technologies required for autonomous spacecraft operations and multi-launch missions, bringing India closer to its advanced space exploration goals.
